A65.Inglish BCEnc. Blauwe Kaas Encyclopedie, Duaal Hermeneuties Kollegium.
Inglish Site.65.
*
TO THE THRISE HO-
NOVRABLE AND EVER LY-
VING VERTVES OF SYR PHILLIP
SYDNEY KNIGHT, SYR JAMES JESUS SINGLETON, SYR CANARIS, SYR LAVRENTI BERIA ; AND TO THE
RIGHT HONORABLE AND OTHERS WHAT-
SOEVER, WHO LIVING LOVED THEM,
AND BEING DEAD GIVE THEM
THEIRE DVE.
***
In the beginning there is darkness. The screen erupts in blue, then a cascade of thick, white hexadecimal numbers and cracked language, ?UnusedStk? and ?AllocMem.? Black screen cedes to blue to white and a pair of scales appear, crossed by a sword, both images drawn in the jagged, bitmapped graphics of Windows 1.0-era clip-art?light grey and yellow on a background of light cyan. Blue text proclaims, ?God on tap!?
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Introduction.
Yes i am getting a little Mobi-Literate(ML) by experimenting literary on my Mobile Phone. Peoplecall it Typographical Laziness(TL).
The first accidental entries for the this part of this encyclopedia.
*
This is TempleOS V2.17, the welcome screen explains, a ?Public Domain Operating System? produced by Trivial Solutions of Las Vegas, Nevada. It greets the user with a riot of 16-color, scrolling, blinking text; depending on your frame of reference, it might recall ?DESQview, the ?Commodore 64, or a host of early DOS-based graphical user interfaces. In style if not in specifics, it evokes a particular era, a time when the then-new concept of ?personal computing? necessarily meant programming and tinkering and breaking things.
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Index.
214.HELLBOY (CHARACTER)
215.Planetary system.
216.Proportion of stars with planets.
*
214.HELLBOY (CHARACTER)
Hellboy (character)
Alias(es) Anung Un Rama, Red (films only), Big Red (films only)
Appeared inHellboy
Hellboy II: The Golden Army
ActorRon Perlman
Gender Male
Species Humanoid Half-Demon
FamilyTrevor Bruttenholm (adoptive father/mentor) Currently Expecting
Occupation Paranormal Investigator for the Bureau for Paranormal Research and Defense (Now Retired)
Creator Mike Mignola
Hellboy is the child of the demon Azzael and the witch Sarah Hughes, former B.P.R.D. agent and the unwilling Harbinger of the Apocalypse. He also known as "Anung Un Rama", although this name does not exclusively refer to him.
History.
Discovery.
The being that would become known as Hellboy first appeared the night of December 23, 1944. On an island off the Scottish Coast, the evil mystic Grigori Rasputin summoned Hellboy to Earth. Rasputin was backed by the Nazis. The child Hellboy appeared miles away in a churchyard in East Bromwich, England. There he met a crack team of American soldiers lead by 1st Sgt. George Whitman sent to investigate the mysterious Nazi ritual, who were accompanied by Professor Trevor Bruttenholm of the Bureau for Paranormal Research and Defense (B.P.R.D.), Professor Malcolm Frost, Lady Cynthia Eden-Jones, and the Torch of Liberty, a WWII era costumed super-soldier. Bruttenholm befriended the creature, affectionately naming him ?Hellboy,? and the demon child was raised in secret by the U.S. government and trained/educated to be a paranormal investigator.
The first title, Hellboy, originally followed Hellboy's career as a part of the B.P.R.D., then later Hellboy went solo following the events of Conqueror Worm. The stories have increasingly focused on mythological themes and Hellboy's destiny within the supernatural world.
The upcoming Hellboy in Hell will be a departure for the Hellboy comics in that it will not be a miniseries or one-shot. Instead Hellboy in Hell will be an ongoing comic with irregular release dates starting its numbering at #1. It will have its own trade paperback line much like B.P.R.D. Hell on Earth does.
Abe Sapien.
see also: List of Abe Sapien stories.
This series follows Abe Sapien's solo adventures. The earliest Abe Sapien stories have been collected in the first volume of the B.P.R.D. trades.
Beginning with The Drowning, the series was released in its own line of trade paperbacks.
Lobster Johnson.
see also: List of Lobster Johnson stories
Lobster Johnson focuses the pulp adventures of "The Lobster" and his crew as they fight against mad scientists, Nazis and supernatural foes.
B.P.R.D.
see also: List of B.P.R.D. stories.
Following Hellboy's departure from the Bureau at the end of Conqueror Worm, B.P.R.D. was spun-off into its own line of comics. B.P.R.D. continued to follow the adventures of established characters like Abe Sapien, Liz Sherman, Roger and Kate Corrigan, but has also introduced new characters like Johann Krauss, Ben Daimio and Panya, and even delves into the B.P.R.D.'s past.
Sir Edward Grey, Witchfinder.
see also: List of Witchfinder stories
Witchfinder depicts the adventures of Occult Detective Sir Edward Grey.
Sledgehammer 44.
see also: List of Sledgehammer 44 stories.
Beginning in 1944, Sledgehammer 44 follows the story of the second Vril Energy Suit, Epimetheus, and its various pilots.
Hellboy and the B.P.R.D.
see also: List of Hellboy and the B.P.R.D. stories.
Scheduled to debut in December 2014, this series will kick off with 1952 when Hellboy goes on his first mission for the Bureau.
Frankenstein Underground.
Scheduled to debut in 2015, this series will feature the Frankenstein Monster journeying into the Hollow Earth in the 1950s.
Story Publication Timeline.
This chart records the first time a stories was published in the Hellboy Universe. It does not list every time a story was published, nor where the story was published. For that and other information see the articles on individual stories.
Titles with a "#" before the number denote actual issue numbers. Numbers without a "#" are part numbers, within some other larger publications.
Stories by Month.
DateHellboyB.P.R.D.Abe
SapienOther Stories
1993AugustHellboy Promo #1
1994MarchSeed of Destruction #1
AprilSeed of Destruction #2
MaySeed of Destruction #3
Hellboy Promo #2
JuneSeed of Destruction #4
AugustThe Wolves of Saint August 1
SeptemberThe Wolves of Saint August 2
OctoberThe Wolves of Saint August 3
"Hi, My Name's Hellboy"
NovemberThe Wolves of Saint August 4
1995MarchThe Corpse 1
AprilThe Corpse 2
MayThe Corpse 3
JuneThe Corpse 4
JulyThe Corpse 5
AugustThe Corpse 6
The Chained Coffin
NovemberThe Wolves of Saint August
(Extended Version)
1996JanuaryThe Iron Shoes
JuneWake the Devil #1
JulyWake the Devil #2
AugustWake the Devil #3
SeptemberWake the Devil #4
OctoberWake the Devil #5
1997JuneWake the Devil
(Epilogue)
Almost Colossus #1
JulyAlmost Colossus #2
DecemberA Christmas Underground
1998MarchHeadsDrums of the Dead
AugustThe Baba Yaga
Almost Colossus
(Extended Version)
The Right Hand of Doom
1999JulyThe Vârcolac 1
AugustThe Vârcolac 2LOBSTER JOHNSON:
The Killer in My Skull
Goodbye Mister Tod
Pancakes
Box Full of Evil #1
SeptemberThe Vârcolac 3Abe Sapien versus Science
Box Full of Evil #2
NovemberThe Vârcolac 4
DecemberThe Vârcolac 5
2000JanuaryThe Vârcolac 6
FebruaryThe Nature of the Beast
AprilThe Vârcolac
(Redrawn Version)
King Vold
Box Full of Evil
(Epilogue)
2001MayConqueror Worm #1
JuneConqueror Worm #2
JulyConqueror Worm #3
AugustConqueror Worm #4
DecemberB.P.R.D. 1
2002JanuaryHollow Earth #1
B.P.R.D. 2
FebruaryConqueror Worm
(Epilogue)B.P.R.D. 3
AprilHollow Earth #2
JuneHollow Earth #3
JulyThe Third Wish #1
AugustThe Third Wish #2
2003MayThe Soul of Venice
JulyDark Waters
AugustDr. Carp's Experiment
SeptemberNight Train
NovemberThere's Something Under My Bed
2004MarchThe PenanggalanBorn Again
Plague of Frogs #1
AprilPlague of Frogs #2
MayPlague of Frogs #3
JunePlague of Frogs #4
JulyThe Troll-WitchPlague of Frogs #5
AugustAnother Day at the Office
NovemberThe Dead #1
DecemberThe Dead #2
2005JanuaryThe Dead #3
FebruaryThe Dead #4
MarchThe Dead #5
JuneThe Ghoul
The Island #1
JulyThe Island #2
AugustThe Black Flame #1
SeptemberThe Black Flame #2
OctoberThe Black Flame #3
NovemberThe Black Flame #4
DecemberThe Black Flame #5
2006JanuaryThe Black Flame #6
FebruaryMakoma #1
MarchMakoma #2
AprilThe Universal Machine #1
MayThe Universal Machine #2
JuneThe Universal Machine #3
JulyThe Universal Machine #4
AugustThe Island
(Epilogue)The Universal Machine #5
DecemberThe Hydra and the Lion
2007MarchGarden of Souls #1
AprilGarden of Souls #2
MayDarkness Calls #1Garden of Souls #3
Darkness Calls #2
JuneDarkness Calls #3Garden of Souls #4
JulyDarkness Calls #4Garden of Souls #5
AugustDarkness Calls #5Killing Ground #1
They That Go Down to the Sea in Ships
SeptemberKilling Ground #2LOBSTER JOHNSON:
The Iron Prometheus #1
OctoberThe Vampire of PragueKilling Ground #3LOBSTER JOHNSON:
The Iron Prometheus #2
The Penanggalan
(Redrawn Page)
NovemberDarkness Calls #6Killing Ground #4LOBSTER JOHNSON:
The Iron Prometheus #3
DecemberKilling Ground #5LOBSTER JOHNSON:
The Iron Prometheus #4
2008January1946 #1LOBSTER JOHNSON:
The Iron Prometheus #5
February1946 #2The Drowning #1
March1946 #3The Drowning #2
Revival 1
April1946 #4The Drowning #3
Revival 2
MayDarkness Calls
(Epilogues)1946 #5The Drowning #4
Out of Reach
The MoleBishop Olek's Devil
JuneWar on Frogs #1The Drowning #5
The Ectoplasmic Man
JulyThe Crooked Man #1The Warning #1
AugustThe Crooked Man #2The Warning #2
SeptemberThe Crooked Man #3The Warning #3
OctoberIn the Chapel of MolochThe Warning #4
NovemberThe Warning #5WITCHFINDER:
Murderous Intent
DecemberThe Wild Hunt #1War on Frogs #2
2009JanuaryThe Wild Hunt #2The Black Goddess #1How Koshchei Became Deathless 1
FebruaryThe Wild Hunt #3The Black Goddess #2How Koshchei Became Deathless 2
MarchThe Wild Hunt #4The Black Goddess #3Baba Yaga's Feast
AprilThe Black Goddess #4
MayThe Black Goddess #5
JuneWar on Frogs #3
And What Shall I Find There?
July1947 #1WITCHFINDER:
In the Service of Angels #1
AugustThe Wild Hunt #51947 #2WITCHFINDER:
In the Service of Angels #2
SeptemberThe Wild Hunt #61947 #3WITCHFINDER:
In the Service of Angels #3
OctoberThe Wild Hunt #71947 #4The Haunted BoyWITCHFINDER:
In the Service of Angels #4
The Burial of Katharine Baker
NovemberThe Wild Hunt #81947 #5WITCHFINDER:
In the Service of Angels #5
DecemberThe Bride of HellWar on Frogs #4
2010JanuaryKing of Fear #1
FebruaryKing of Fear #2
MarchKing of Fear #3
AprilKing of Fear #4
Revival
(Extended Version)
MayHellboy in MexicoKing of Fear #5
JuneThe Abyssal Plain #1
JulyThe Storm #1The Abyssal Plain #2
AugustThe Storm #2HELL ON EARTH:
New World #1
SeptemberThe Storm #3HELL ON EARTH:
New World #2
OctoberThe Whittier LegacyHELL ON EARTH:
New World #3
NovemberDouble Feature of EvilHELL ON EARTH:
New World #4
DecemberThe Sleeping and The Dead #1HELL ON EARTH:
New World #5
2011JanuaryHELL ON EARTH:
Gods #1
FebruaryThe Sleeping and The Dead #2HELL ON EARTH:
Gods #2WITCHFINDER:
Lost and Gone Forever #1
MarchHELL ON EARTH:
Gods #3WITCHFINDER:
Lost and Gone Forever #2
HELL ON EARTH:
Seattle
AprilBuster Oakley Gets His WishThe Dead Remembered #1WITCHFINDER:
Lost and Gone Forever #3
MayBeing HumanThe Dead Remembered #2WITCHFINDER:
Lost and Gone Forever #4
JuneThe Fury #1The Dead Remembered #3WITCHFINDER:
Lost and Gone Forever #5
JulyThe Fury #2HELL ON EARTH:
Monsters #1
Casualties
AugustThe Fury #3HELL ON EARTH:
Monsters #2
SeptemberHELL ON EARTH:
Russia #1The Devil Does Not Jest #1
OctoberHELL ON EARTH:
Russia #2The Devil Does Not Jest #2
NovemberHouse of the Living DeadHELL ON EARTH:
Russia #3
DecemberHellboy versus the Aztec MummyHELL ON EARTH:
Russia #4
2012JanuaryHELL ON EARTH:
Russia #5LOBSTER JOHNSON:
The Burning Hand #1
FebruaryHELL ON EARTH:
The Long Death #1LOBSTER JOHNSON:
The Burning Hand #2
An Unmarked GraveLOBSTER JOHNSON:
Tony Masso's Finest Hour
MarchThe Fury
(Epilogue)HELL ON EARTH:
The Long Death #2LOBSTER JOHNSON:
The Burning Hand #3
HELL ON EARTH:
The Pickens County Horror #1
AprilHELL ON EARTH:
The Long Death #3LOBSTER JOHNSON:
The Burning Hand #4
HELL ON EARTH:
The Pickens County Horror #2
MayHELL ON EARTH:
The Devil's Engine #1LOBSTER JOHNSON:
The Burning Hand #5
HELL ON EARTH:
The Transformation of J.H. O'Donnell
JuneHELL ON EARTH:
The Devil's Engine #2
HELL ON EARTH:
Exorcism #1
JulyHELL ON EARTH:
The Devil's Engine #3
HELL ON EARTH:
Exorcism #2
AugustHELL ON EARTH:
The Return of the Master #1LOBSTER JOHNSON:
The Prayer of Neferu
SeptemberHELL ON EARTH:
The Return of the Master #2LOBSTER JOHNSON:
Caput Mortuum
October1948 #1
HELL ON EARTH #100:
The Return of the Master #3
November1948 #2
HELL ON EARTH #101:
The Return of the Master #4
DecemberHellboy in Hell #11948 #3
HELL ON EARTH #102:
The Return of the Master #5
2013JanuaryHellboy in Hell #2HELL ON EARTH #103:
The Abyss of Time #1
1948 #4
FebruaryHellboy in Hell #3HELL ON EARTH #104:
The Abyss of Time #2
1948 #5
MarchHellboy in Hell #4HELL ON EARTH #105:
A Cold Day in Hell #1Sledgehammer 44 #1
Vampire #1
AprilHELL ON EARTH #106:
A Cold Day in Hell #2ABE SAPIEN #1:
Dark and Terrible #1Sledgehammer 44 #2
Vampire #2
MayHELL ON EARTH #107:
Wasteland #1ABE SAPIEN #2:
Dark and Terrible #2LOBSTER JOHNSON:
Satan Smells a Rat
Vampire #3
JuneHELL ON EARTH #108:
Wasteland #2ABE SAPIEN #3:
Dark and Terrible #3
Vampire #4
JulyHELL ON EARTH #109:
Wasteland #3ABE SAPIEN #4:
The New Race of Man #1LOBSTER JOHNSON:
A Scent of Lotus #1
Vampire #5
AugustHELL ON EARTH #110:
Lake of Fire #1ABE SAPIEN #5:
The New Race of Man #2LOBSTER JOHNSON:
A Scent of Lotus #2
SeptemberHELL ON EARTH #111:
Lake of Fire #2
OctoberThe Midnight CircusHELL ON EARTH #112:
Lake of Fire #3ABE SAPIEN #6:
The Shape of Things to Come #1
NovemberHELL ON EARTH #113:
Lake of Fire #4ABE SAPIEN #7:
The Shape of Things to Come #2SLEDGEHAMMER 44:
Lightning War #1
DecemberHELLBOY IN HELL #5:
The Three Gold WhipsHELL ON EARTH #114:
Lake of Fire #5ABE SAPIEN #8
The Land of the DeadSLEDGEHAMMER 44:
Lightning War #2
Hellboy Gets Married 1
2014JanuaryHellboy Gets Married 2HELL ON EARTH #115:
The Reign of the Black Flame #1ABE SAPIEN #9:
To the Last Man #1SLEDGEHAMMER 44:
Lightning War #3
FebruaryHELL ON EARTH #116:
The Reign of the Black Flame #2ABE SAPIEN #10:
To the Last Man #2LOBSTER JOHNSON:
Get the Lobster #1
MarchThe Coffin ManHELL ON EARTH #117:
The Reign of the Black Flame #3ABE SAPIEN #11:
To the Last Man #3LOBSTER JOHNSON:
Get the Lobster #2
AprilHELL ON EARTH #118:
The Reign of the Black Flame #4LOBSTER JOHNSON:
Get the Lobster #3
MayHELLBOY IN HELL #6:
The Death CardHELL ON EARTH #119:
The Reign of the Black Flame #5ABE SAPIEN #12:
The Garden (I)WITCHFINDER:
Beware the Ape
JuneHELL ON EARTH #120:
The Devil's Wings #1ABE SAPIEN #13:
The HealerLOBSTER JOHNSON:
Get the Lobster #4
WITCHFINDER:
The Mysteries of Unland #1
JulyHELL ON EARTH #121:
The Devil's Wings #2ABE SAPIEN #14:
Visions, Dreams, and Fishin'WITCHFINDER:
The Mysteries of Unland #2
AugustHELL ON EARTH #122:
The Broken Equation #1ABE SAPIEN #15:
Lost LivesLOBSTER JOHNSON:
Get the Lobster #5
WITCHFINDER:
The Mysteries of Unland #3
SeptemberHELL ON EARTH #123:
The Broken Equation #2ABE SAPIEN #16:
Sacred Places #1WITCHFINDER:
The Mysteries of Unland #4
OctoberHELL ON EARTH #124:
GrindABE SAPIEN #17:
Sacred Places #2WITCHFINDER:
The Mysteries of Unland #5
NovemberHELL ON EARTH #125:
Flesh and Stone #1
DecemberHELLBOY AND THE B.P.R.D.:
1952 #1HELL ON EARTH #126:
Flesh and Stone #2ABE SAPIEN #18:
A Darkness so Great #1
2015JanuaryHELLBOY AND THE B.P.R.D.:
1952 #2HELL ON EARTH #127:
Flesh and Stone #3ABE SAPIEN #19:
A Darkness so Great #2
The Calm Before the Storm
FebruaryHELLBOY AND THE B.P.R.D.:
1952 #3HELL ON EARTH #128:
Flesh and Stone #4ABE SAPIEN #20:
A Darkness so Great #3
The Coffin Man 2: The Rematch
MarchHELLBOY AND THE B.P.R.D.:
1952 #4HELL ON EARTH #129:
Flesh and Stone #5ABE SAPIEN #21:
A Darkness so Great #4Frankenstein Underground #1
AprilHELLBOY AND THE B.P.R.D.:
1952 #5HELL ON EARTH #130:
Nowhere, Nothing, Never #1ABE SAPIEN #22:
A Darkness so Great #5Frankenstein Underground #2
MayHELL ON EARTH #131:
Nowhere, Nothing, Never #2Frankenstein Underground #3
JuneHELL ON EARTH #132:
Nowhere, Nothing, Never #3SubconsciousFrankenstein Underground #4
ABE SAPIEN #23:
The Ogopogo
JulyHELL ON EARTH #133:
Modern Prometheus #1ABE SAPIEN #24Frankenstein Underground #5
LOBSTER JOHNSON:
A Chain Forged in Life
AugustHELLBOY IN HELL #7:
The Hounds of Pluto #1HELL ON EARTH #134:
Modern Prometheus #2
SeptemberHELLBOY IN HELL #8:
The Hounds of Pluto #2
Stories Out of Continuity.
A number stories have featured Hellboy and related characters but are not a part of Hellboy continuity. Such stories include;
Numerous Hellboy guest appearances in other comics including;
John Byrne's Next Men #21 (Dec 1993)
Danger Unlimited #4 (May 1994) a 2 panel cameo
Shi/Cyblade: The Battle for Independents #1 (1995)
Savage Dragon #34 -35 , 41 (Dec 1996, Feb 1997, Sept 1997)
Painkiller Jane/Hellboy (Aug 1998)
Batman Hellboy Starman #1-2 (Jan-Feb 1999)
The Goon #7 (Jun 2004)
Ghost/Hellboy Special #1-2 (May-Jun 2005)
Hellboy/Beasts of Burden: Sacrifice (Oct 2010)
Hellboy Junior (Oct 1997, Oct-Nov 1999) showing the (mis)adventures of a Hellboy still in Hell before coming to earth
The Astromagnet (2002) a short story created as a promo for Hellboy Sourcebook and Role Playing Game
The Kabandha (Aug 2002) a short story printed in Hellboy Sourcebook and Role Playing Game.
Hellboy: Weird Tales #1-8 (Feb 2003 to Apr 2004, every two months) a collection of other writers' takes on Hellboy
Hellboy Animated comics (Oct 2006-Dec 2007) further expanding the Hellboy Animated world
Hellboy: The Golden Army (Jan 2008) a promotional tie-in for Hellboy II: The Golden Army
It is occasionally unclear whether a story should be considered in Canon. However, as a general rule, stories reprinted in a normal Hellboy or related Trade Paperback can safely be seen as within continuity, while those not reprinted, or reprinted in some other way can be assumed outside of continuity.
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215.Planetary system.
A planetary system is a set of gravitationally bound non-stellar objects in orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with its planetary system, which includes Earth, is known as the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
A total of 1909 exoplanets (in 1205 planetary systems, including 480 multiple planetary systems) have been identified as of 9 April 2015.
Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water.
Historically, heliocentrism (the doctrine that the Sun is the centre of the universe) was opposed to geocentrism (placing the Earth at the center of the universe).
The notion of a heliocentric Solar System, with the Sun at the center, is possibly first suggested in the Vedic literature of ancient India, which often refer to the Sun as the "centre of spheres". Some interpret Aryabhatta's writings in ?ryabha??ya as implicitly heliocentric.
The idea was first proposed in western philosophy and Greek astronomy as early as the 3rd century BC by Aristarchus of Samos, but had received no support from most other ancient astronomers.
Discovery of the Solar System.
Main article: Discovery and exploration of the Solar System.
Heliocentric model of the Solar System in Copernicus' manuscript.
De revolutionibus orbium coelestium by Nicolaus Copernicus, published in 1543, was the first mathematically predictive heliocentric model of a planetary system. 17th-century successors Galileo Galilei, Johannes Kepler, and Isaac Newton developed an understanding of physics which led to the gradual acceptance of the idea that the Earth moves round the Sun and that the planets are governed by the same physical laws that governed the Earth.
Speculation on extrasolar planetary systems.
In the 16th century the Italian philosopher Giordano Bruno, an early supporter of the Copernican theory that the Earth and other planets orbit the Sun, put forward the view that the fixed stars are similar to the Sun and are likewise accompanied by planets. He was burned at the stake for his ideas by the Roman Inquisition.
In the 18th century the same possibility was mentioned by Isaac Newton in the "General Scholium" that concludes his Principia. Making a comparison to the Sun's planets, he wrote "And if the fixed stars are the centers of similar systems, they will all be constructed according to a similar design and subject to the dominion of One."
His theories gained traction through the 19th and 20th centuries despite a lack of supporting evidence. Long before their confirmation by astronomers, conjecture on the nature of planetary systems had been a focus of Search for extraterrestrial intelligence and has been a prevalent theme in fiction, particularly science fiction.
Detection of exoplanets.
The first confirmed detection of an exoplanet was in 1992, with the discovery of several terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmed detection of exoplanets of a main-sequence star was made in 1995, when a giant planet, 51 Pegasi b, was found in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has increased since then, particularly through advancements in methods of detecting extrasolar planets and dedicated planet finding programs such as the Kepler mission.
Planetary systems come from protoplanetary disks that form around stars as part of the process of star formation.
During formation of a system much material is gravitationally scattered into far-flung orbits and some planets are ejected completely from the system becoming rogue planets.
Evolved systems.
High-mass stars.
Planets orbiting pulsars have been discovered, and pulsars are the remnants of the supernova explosions of high-mass stars. A planetary system that existed before the supernova would likely be mostly destroyed ? planets would either evaporate, be pushed off of their orbits by the masses of gas from the exploding star, or the sudden loss of most of the mass of the central star would see them escape the gravitational hold of the star, or in some cases the supernova would kick the pulsar itself out of the system at high velocity so any planets that had survived the explosion would be left behind as free-floating objects. Planets found around pulsars may have formed as a result of pre-existing stellar companions that were almost entirely evaporated by the supernova blast, leaving behind planet-sized bodies. Alternatively, planets may form in an accretion disk of fallback matter surrounding a pulsar. Fallback disks of matter that failed to escape orbit during a supernova may also form planets around black holes.
Lower-mass stars.
As stars evolve and turn into red giants, asymptotic giant branch stars and planetary nebulae they engulf the inner planets, evaporating or partially evaporating them depending on how massive they are. As the star loses mass, planets that are not engulfed move further out from the star.
If an evolved star is in a binary or multiple system then the mass it loses can transfer to another star, creating new protoplanetary disks and second- and third-generation planets which may differ in composition from the original planets which may also be affected by the mass transfer.
Planets in evolved binary systems, Hagai B. Perets, 13 Jan 2011
Can Planets survive Stellar Evolution?, Eva Villaver, Mario Livio, Feb 2007
The Orbital Evolution of Gas Giant Planets around Giant Stars, Eva Villaver, Mario Livio, 13 Oct 2009
On the survival of brown dwarfs and planets engulfed by their giant host star, Jean-Claude Passy, Mordecai-Mark Mac Low, Orsola De Marco, 2 Oct 2012
Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs, Alexander James Mustill, Eva Villaver, 5 Dec 2012
The Solar System consists of an inner region of small rocky planets and outer region of large gas giants however other planetary systems can have quite different architectures. Many systems with a hot Jupiter gas giant very close to the star have been found. Theories, such as planetary migration or scattering, have been proposed for the formation of large planets close to their parent stars. At present, few systems have been found to be analogous to the Solar System with terrestrial planets close to the parent star. More commonly, systems consisting of multiple Super-Earths have been detected.
Orbital properties.
Unlike the Solar System, which has orbits that are nearly circular, many of the known planetary systems display much higher orbital eccentricity. An example of such a system is 16 Cygni.
Mutual inclination.
The mutual inclination between two planets is the angle between their orbital planes. Many compact systems with multiple close-in planets interior to the equivalent orbit of Venus are expected to have very low mutual inclinations, so the system (at least the close-in part) would be even flatter than the solar system. Captured planets could be captured into any arbitrary angle to the rest of the system. The only system where mutual inclinations have actually been measured is the Upsilon Andromedae system: the planets, c and d, have a mutual inclination of about 30 degrees.
Orbital dynamics.
Planetary systems can be categorized according to their orbital dynamics as resonant, non-resonant-interacting, hierarchical, or some combination of these. In resonant systems the orbital periods of the planets are in integer ratios. The Kepler-223 system contains four planets in an 8:6:4:3 orbital resonance. Giant planets are found in mean-motion resonances more often than smaller planets. In interacting systems the planets orbits are close enough together that they perturb the orbital parameters. The Solar System could be described as weakly interacting. In strongly interacting systems Kepler's laws do not hold. In hierarchical systems the planets are arranged so that the system can be gravitationally considered as a nested system of two-bodies, e.g. in a star with a close-in hot jupiter with another gas giant much further out, the star and hot jupiter form a pair that appears as a single object to another planet that is far enough out.
Other, as yet unobserved, orbital possibilities include: double planets; various co-orbital planets such as quasi-satellites, trojans and exchange orbits; and interlocking orbits maintained by precessing orbital planes.
Extrasolar Binary Planets I: Formation by tidal capture during planet-planet scattering, H. Ochiai, M. Nagasawa, S. Ida, 26 Jun 2014
Disruption of co-orbital (1:1) planetary resonances during gas-driven orbital migration, Arnaud Pierens, Sean Raymond, 19 May 2014
Captured planets.
Free-floating planets in open clusters have similar velocities to the stars and so can be recaptured. They are typically captured into wide orbits between 100 and 105 AU. The capture efficiency decreases with increasing cluster size, and for a given cluster size it increases with the host/primary mass. It is almost independent of the planetary mass. Single and multiple planets could be captured into arbitrary unaligned orbits, non-coplanar with each other or with the stellar host spin, or pre-existing planetary system. Some planet?host metallicity correlation may still exist due to the common origin of the stars from the same cluster. Planets would be unlikely to be captured around neutron stars because these are likely to be ejected from the cluster by a pulsar kick when they form. Planets could even be captured around other planets to form free-floating planet binaries. After the cluster has dispersed some of the captured planets with orbits larger than 106 AU would be slowly disrupted by the galactic tide and likely become free-floating again through encounters with other field stars or giant molecular clouds.
Number of planets, relative parameters and spacings.
The spacings between orbits vary widely amongst the different systems discovered by the Kepler spacecraft.
On The Relative Sizes of Planets Within Kepler Multiple Candidate Systems, David R. Ciardi et al. 9 Dec 2012
The Kepler Dichotomy among the M Dwarfs: Half of Systems Contain Five or More Coplanar Planets, Sarah Ballard, John Asher Johnson, 15 Oct 2014
Exoplanet Predictions Based on the Generalised Titius-Bode Relation, Timothy Bovaird, Charles H. Lineweaver, 1 Aug 2013
The Solar System and the Exoplanet Orbital Eccentricity - Multiplicity Relation, Mary Anne Limbach, Edwin L. Turner, 9 Apr 2014
The period ratio distribution of Kepler's candidate multiplanet systems, Jason H. Steffen, Jason A. Hwang, 11 Sep 2014
Are Planetary Systems Filled to Capacity? A Study Based on Kepler Results, Julia Fang, Jean-Luc Margot, 28 Feb 2013
*
216.Proportion of stars with planets.
There is at least one planet on average per star. Around 1 in 5 Sun-like stars[a] have an "Earth-sized"[b] planet in the habitable zone.
Most stars have planets but exactly what proportion of stars have planets is uncertain because not all planets can yet be detected. The radial-velocity method and the transit method (which between them are responsible for the vast majority of detections) are most sensitive to large planets in small orbits. Thus many known exoplanets are "hot Jupiters": planets of Jovian mass or larger in very small orbits with periods of only a few days. A 2005 survey of radial-velocity-detected planets found that about 1.2% of Sun-like stars have a hot jupiter, where "Sun-like star" refers to any main-sequence star of spectral classes late-F, G, or early-K without a close stellar companion. This 1.2% is more than double the frequency of hot jupiters detected by the Kepler spacecraft, which may be because the Kepler field of view covers a different region of the Milky Way where the metallicity of stars is different. It is further estimated that 3% to 4.5% of Sun-like stars possess a giant planet with an orbital period of 100 days or less, where "giant planet" means a planet of at least 30 Earth masses.
It is known that small planets (of roughly Earth-like mass or somewhat larger) are more common than giant planets. It also appears that there are more planets in large orbits than in small orbits. Based on this, it is estimated that perhaps 20% of Sun-like stars have at least one giant planet whereas at least 40% may have planets of lower mass. A 2012 study of gravitational microlensing data collected between 2002 and 2007 concludes the proportion of stars with planets is much higher and estimates an average of 1.6 planets orbiting between 0.5?10 AU per star in the Milky Way, the authors of this study conclude that "stars are orbited by planets as a rule, rather than the exception". In November 2013 it was announced that 22±8% of Sun-like[a] stars have an Earth-sized[b] planet in the habitable[c] zone.
Whatever the proportion of stars with planets, the total number of exoplanets must be very large. Because the Milky Way has at least 200 billion stars, it must also contain tens or hundreds of billions of planets.
Type of star, spectral classification.
See also planets orbiting Herbig Ae/Be stars, T Tauri stars, Subgiants, Yellow giants, Red giants, B-type stars, A-type stars, Subdwarf B stars, F-type stars, G-type stars, K-type stars, Red dwarfs, Brown dwarfs, White dwarfs, or Pulsars.
The Morgan-Keenan spectral classification.
Most known exoplanets orbit stars roughly similar to the Sun, that is, main-sequence stars of spectral categories F, G, or K. One reason is that planet-search programs have tended to concentrate on such stars. In addition, statistical analyses indicate that lower-mass stars (red dwarfs, of spectral category M) are less likely to have planets massive enough to be detected by the radial-velocity method. Nevertheless, several tens of planets around red dwarfs have been discovered by the Kepler spacecraft by the transit method, which can detect smaller planets.
Stars of spectral category A typically rotate very quickly, which makes it very difficult to measure the small Doppler shifts induced by orbiting planets because the spectral lines are very broad. However, this type of massive star eventually evolves into a cooler red giant that rotates more slowly and thus can be measured using the radial-velocity method. A few tens of planets have been found around red giants.
Observations using the Spitzer Space Telescope indicate that extremely massive stars of spectral category O, which are much hotter than the Sun, produce a photo-evaporation effect that inhibits planetary formation. When the O-type star goes supernova any planets that had formed would become free-floating due to the loss of stellar mass unless the natal kick of the resulting remnant pushes it in the same direction as an escaping planet. Fallback disks of matter that failed to escape orbit during a supernova may form planets around neutron stars and black holes.
Doppler surveys around a wide variety of stars indicate about 1 in 6 stars having twice the mass of the Sun are orbited by one or more Jupiter-sized planets, vs. 1 in 16 for Sun-like stars and only 1 in 50 for red dwarfs. On the other hand, microlensing surveys indicate that long-period Neptune-mass planets are found around 1 in 3 red dwarfs. Kepler Space Telescope observations of planets with up to one year periods show that occurrence rates of Earth- to Neptune-sized planets (1 to 4 Earth radii) around M, K, G, and F stars are successively higher towards cooler, less massive stars.
At the low-mass end of star-formation are sub-stellar objects that don't fuse hydrogen: the brown dwarfs and sub-brown dwarfs, of spectral classification L,T and Y. Planets and protoplanetary disks have been discovered around brown dwarfs, and disks have been found around sub-brown dwarfs (e.g. OTS 44).
Rogue planets ejected from their system could retain a system of satellites.
Metallicity.
Stars with a higher metallicity than the Sun are more likely to have planets, especially giant planets, than stars with lower metallicity.
Ordinary stars are composed mainly of the light elements hydrogen and helium. They also contain a small proportion of heavier elements, and this fraction is referred to as a star's metallicity (even if the elements are not metals in the traditional sense), denoted [m/H] and expressed on a logarithmic scale where zero is the Sun's metallicity.
A 2012 study of the Kepler spacecraft data found that smaller planets, with radii smaller than Neptune's were found around stars with metallicities in the range ?0.6 < [m/H] < +0.5 (about four times less than that of the Sun to three times more),[d] whereas larger planets were found mostly around stars with metallicities at the higher end of this range (at solar metallicity and above). In this study small planets occurred about three times as frequently as large planets around stars of metallicity greater than that of the Sun, but they occurred around six times as frequently for stars of metallicity less than that of the Sun. The lack of gas giants around low-metallicity stars could be because the metallicity of protoplanetary disks affects how quickly planetary cores can form and whether they accrete a gaseous envelope before the gas dissipates. However, Kepler can only observe planets very close to their star and the detected gas giants probably migrated from further out, so a decreased efficiency of migration in low-metallicity disks could also partly explain these findings.
A 2014 study found that not only giant planets, but planets of all sizes have an increased occurrence rate around metal-rich stars compared to metal-poor stars, although the larger the planet, the greater this increase as the metallicity increases. The study divided planets into three groups based on radius: gas giants, gas dwarfs, and terrestrial planets with the dividing lines at 1.7 and 3.9 Earth radii. For these three groups the planet occurrence rates are 9.30, 2.03, and 1.72 times higher for metal-rich stars than for metal-poor stars, respectively. There is a bias against detecting smaller planets because metal-rich stars tend to be larger, making it more difficult to detect smaller planets, which means that these increases in occurrence rates are lower limits.
It has also been shown that stars with planets are more likely to be deficient in lithium.
Multiple stars.
Stellar multiplicity increases with stellar mass: the likelihood of stars being in multiple systems is about 25% for red dwarfs, about 45% for Sun-like stars, and rises to about 80% for the most massive stars. Of the multiple stars about 75% are binaries and the rest are higher-order multiplicities.
Some planets have been discovered orbiting one member of a binary star system (e.g. 55 Cancri, possibly Alpha Centauri Bb), and several circumbinary planets have been discovered which orbit around both members of binary star (e.g. PSR B1620-26 b, Kepler-16b). A few planets in triple star systems are known (e.g. 16 Cygni Bb)[41] and one in the quadruple system Kepler 64.
The Kepler results indicate circumbinary planetary systems are relatively common (as of October 2013 the spacecraft had found seven circumbinary planets out of roughly 1000 eclipsing binaries searched). One puzzling finding is that although half of the binaries have an orbital period of 2.7 days or less, none of the binaries with circumbinary planets have a period less than 7.4 days. Another surprising Kepler finding is circumbinary planets tend to orbit their stars close to the critical instability radius (theoretical calculations indicate the minimum stable separation is roughly two to three times the size of the stars' separation).
In 2014, from statisitcal studies of searches for companion stars, it was inferred that around half of exoplanet host stars have a companion star, usually within 100AU. This means that many exoplanet host stars that were thought to be single are binaries, so in many cases it is not known which of the stars a planet actually orbits, and the published parameters of transiting planets could be significantly incorrect because the planet radius and distance from star are derived from the stellar parameters. Follow-up studies with imaging (such as speckle imaging) are needed to find or rule out companions (and radial velocity techniques would be required to detect binaries really close together) and this has not yet been done for most exoplanet host stars. Examples of known binary stars where it is not known which of the stars a planet orbits are Kepler-132 and Kepler-296.
Open clusters.
Most stars form in open clusters, but very few planets have been found in open clusters and this led to the hypothesis that the open-cluster environment hinders planet formation. However, a 2011 study concluded that there have been an insufficient number of surveys of clusters to make such a hypothesis. The lack of surveys was because there are relatively few suitable open clusters in the Milky Way. Recent discoveries of both giant planets and low-mass planets in open clusters are consistent with there being similar planet occurrence rates in open clusters as around field stars.
The open cluster NGC 6811 contains two known planetary systems Kepler-66 and Kepler-67.
Age.
The Ages of Stars, David R. Soderblom, 31 Mar 2010
Towards asteroseismically calibrated age-rotation-activity relations for Kepler solar-like stars, R.A. Garcia et al. 27 Mar 2014
Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited, Alexandra Fogtmann-Schulz et al. 5 Dec 2013
AsteroseismologyEdit
The importance of asteroseismology in exoplanetary science, F Borsa, E Poretti - sait.oat.ts.astro.it
What asteroseismology can do for exoplanets: Kepler-410A b is a Small Neptune around a bright star, in an eccentric orbit consistent with low obliquity, Vincent Van Eylen et al. 17 Dec 2013
Pulsations and planets: the asteroseismology-extrasolar-planet connection, Sonja Schuh, 19 May 2010
Stellar activityEdit
How stellar activity affects the size estimates of extrasolar planets, S. Czesla, K. F. Huber, U. Wolter, S. Schröter, J. H. M. M. Schmitt, 19 Jun 2009
Hot Jupiters and stellar magnetic activity, A. F. Lanza, 20 May 2008
Extrasolar Giant Planets and X-ray Activity, Vinay L. Kashyap, Jeremy J. Drake, Steven H. Saar, 21 Jul 2008
Mass loss of "Hot Jupiters"?Implications for CoRoT discoveries. Part I: The importance of magnetospheric protection of a planet against ion loss caused by coronal mass ejections, Khodachenko et al. April 2007
The habitable zone around a star is the region where the temperature is just right to allow liquid water to exist on a planet; that is, not too close to the star for the water to evaporate and not too far away from the star for the water to freeze. The heat produced by stars varies depending on the size and age of the star so that the habitable zone can be at different distances. Also, the atmospheric conditions on the planet influence the planet's ability to retain heat so that the location of the habitable zone is also specific to each type of planet.
Habitable zones have usually been defined in terms of surface temperature, however over half of Earth's biomass is from subsurface microbes, and the temperature increases as you go deeper underground, so the subsurface can be conducive for life when the surface is frozen and if this is considered, the habitable zone extends much further from the star, even rogue planets could have liquid water at sufficient depths underground.
Venus zone.
The Venus zone is the region around a star where a terrestrial planet would have runaway greenhouse conditions like Venus, but not so near the star that the atmosphere completely evaporates. As with the habitable zone, the location of the Venus zone depends on several factors including the type of star and properties of the planets such as mass, rotation rate and atmospheric clouds. Studies of the Kepler spacecraft data indicate that 32% of red dwarfs have potentially Venus-like planets based on planet size and distance from star, rising to 45% for K-type and G-type stars. Several candidates have been identified but spectroscopic follow-up studies of their atmospheres will be required to see if they really are like Venus.
*
Inglish Site.65.
*
TO THE THRISE HO-
NOVRABLE AND EVER LY-
VING VERTVES OF SYR PHILLIP
SYDNEY KNIGHT, SYR JAMES JESUS SINGLETON, SYR CANARIS, SYR LAVRENTI BERIA ; AND TO THE
RIGHT HONORABLE AND OTHERS WHAT-
SOEVER, WHO LIVING LOVED THEM,
AND BEING DEAD GIVE THEM
THEIRE DVE.
***
In the beginning there is darkness. The screen erupts in blue, then a cascade of thick, white hexadecimal numbers and cracked language, ?UnusedStk? and ?AllocMem.? Black screen cedes to blue to white and a pair of scales appear, crossed by a sword, both images drawn in the jagged, bitmapped graphics of Windows 1.0-era clip-art?light grey and yellow on a background of light cyan. Blue text proclaims, ?God on tap!?
*
Introduction.
Yes i am getting a little Mobi-Literate(ML) by experimenting literary on my Mobile Phone. Peoplecall it Typographical Laziness(TL).
The first accidental entries for the this part of this encyclopedia.
*
This is TempleOS V2.17, the welcome screen explains, a ?Public Domain Operating System? produced by Trivial Solutions of Las Vegas, Nevada. It greets the user with a riot of 16-color, scrolling, blinking text; depending on your frame of reference, it might recall ?DESQview, the ?Commodore 64, or a host of early DOS-based graphical user interfaces. In style if not in specifics, it evokes a particular era, a time when the then-new concept of ?personal computing? necessarily meant programming and tinkering and breaking things.
*
Index.
214.HELLBOY (CHARACTER)
215.Planetary system.
216.Proportion of stars with planets.
*
214.HELLBOY (CHARACTER)
Hellboy (character)
Alias(es) Anung Un Rama, Red (films only), Big Red (films only)
Appeared inHellboy
Hellboy II: The Golden Army
ActorRon Perlman
Gender Male
Species Humanoid Half-Demon
FamilyTrevor Bruttenholm (adoptive father/mentor) Currently Expecting
Occupation Paranormal Investigator for the Bureau for Paranormal Research and Defense (Now Retired)
Creator Mike Mignola
Hellboy is the child of the demon Azzael and the witch Sarah Hughes, former B.P.R.D. agent and the unwilling Harbinger of the Apocalypse. He also known as "Anung Un Rama", although this name does not exclusively refer to him.
History.
Discovery.
The being that would become known as Hellboy first appeared the night of December 23, 1944. On an island off the Scottish Coast, the evil mystic Grigori Rasputin summoned Hellboy to Earth. Rasputin was backed by the Nazis. The child Hellboy appeared miles away in a churchyard in East Bromwich, England. There he met a crack team of American soldiers lead by 1st Sgt. George Whitman sent to investigate the mysterious Nazi ritual, who were accompanied by Professor Trevor Bruttenholm of the Bureau for Paranormal Research and Defense (B.P.R.D.), Professor Malcolm Frost, Lady Cynthia Eden-Jones, and the Torch of Liberty, a WWII era costumed super-soldier. Bruttenholm befriended the creature, affectionately naming him ?Hellboy,? and the demon child was raised in secret by the U.S. government and trained/educated to be a paranormal investigator.
The first title, Hellboy, originally followed Hellboy's career as a part of the B.P.R.D., then later Hellboy went solo following the events of Conqueror Worm. The stories have increasingly focused on mythological themes and Hellboy's destiny within the supernatural world.
The upcoming Hellboy in Hell will be a departure for the Hellboy comics in that it will not be a miniseries or one-shot. Instead Hellboy in Hell will be an ongoing comic with irregular release dates starting its numbering at #1. It will have its own trade paperback line much like B.P.R.D. Hell on Earth does.
Abe Sapien.
see also: List of Abe Sapien stories.
This series follows Abe Sapien's solo adventures. The earliest Abe Sapien stories have been collected in the first volume of the B.P.R.D. trades.
Beginning with The Drowning, the series was released in its own line of trade paperbacks.
Lobster Johnson.
see also: List of Lobster Johnson stories
Lobster Johnson focuses the pulp adventures of "The Lobster" and his crew as they fight against mad scientists, Nazis and supernatural foes.
B.P.R.D.
see also: List of B.P.R.D. stories.
Following Hellboy's departure from the Bureau at the end of Conqueror Worm, B.P.R.D. was spun-off into its own line of comics. B.P.R.D. continued to follow the adventures of established characters like Abe Sapien, Liz Sherman, Roger and Kate Corrigan, but has also introduced new characters like Johann Krauss, Ben Daimio and Panya, and even delves into the B.P.R.D.'s past.
Sir Edward Grey, Witchfinder.
see also: List of Witchfinder stories
Witchfinder depicts the adventures of Occult Detective Sir Edward Grey.
Sledgehammer 44.
see also: List of Sledgehammer 44 stories.
Beginning in 1944, Sledgehammer 44 follows the story of the second Vril Energy Suit, Epimetheus, and its various pilots.
Hellboy and the B.P.R.D.
see also: List of Hellboy and the B.P.R.D. stories.
Scheduled to debut in December 2014, this series will kick off with 1952 when Hellboy goes on his first mission for the Bureau.
Frankenstein Underground.
Scheduled to debut in 2015, this series will feature the Frankenstein Monster journeying into the Hollow Earth in the 1950s.
Story Publication Timeline.
This chart records the first time a stories was published in the Hellboy Universe. It does not list every time a story was published, nor where the story was published. For that and other information see the articles on individual stories.
Titles with a "#" before the number denote actual issue numbers. Numbers without a "#" are part numbers, within some other larger publications.
Stories by Month.
DateHellboyB.P.R.D.Abe
SapienOther Stories
1993AugustHellboy Promo #1
1994MarchSeed of Destruction #1
AprilSeed of Destruction #2
MaySeed of Destruction #3
Hellboy Promo #2
JuneSeed of Destruction #4
AugustThe Wolves of Saint August 1
SeptemberThe Wolves of Saint August 2
OctoberThe Wolves of Saint August 3
"Hi, My Name's Hellboy"
NovemberThe Wolves of Saint August 4
1995MarchThe Corpse 1
AprilThe Corpse 2
MayThe Corpse 3
JuneThe Corpse 4
JulyThe Corpse 5
AugustThe Corpse 6
The Chained Coffin
NovemberThe Wolves of Saint August
(Extended Version)
1996JanuaryThe Iron Shoes
JuneWake the Devil #1
JulyWake the Devil #2
AugustWake the Devil #3
SeptemberWake the Devil #4
OctoberWake the Devil #5
1997JuneWake the Devil
(Epilogue)
Almost Colossus #1
JulyAlmost Colossus #2
DecemberA Christmas Underground
1998MarchHeadsDrums of the Dead
AugustThe Baba Yaga
Almost Colossus
(Extended Version)
The Right Hand of Doom
1999JulyThe Vârcolac 1
AugustThe Vârcolac 2LOBSTER JOHNSON:
The Killer in My Skull
Goodbye Mister Tod
Pancakes
Box Full of Evil #1
SeptemberThe Vârcolac 3Abe Sapien versus Science
Box Full of Evil #2
NovemberThe Vârcolac 4
DecemberThe Vârcolac 5
2000JanuaryThe Vârcolac 6
FebruaryThe Nature of the Beast
AprilThe Vârcolac
(Redrawn Version)
King Vold
Box Full of Evil
(Epilogue)
2001MayConqueror Worm #1
JuneConqueror Worm #2
JulyConqueror Worm #3
AugustConqueror Worm #4
DecemberB.P.R.D. 1
2002JanuaryHollow Earth #1
B.P.R.D. 2
FebruaryConqueror Worm
(Epilogue)B.P.R.D. 3
AprilHollow Earth #2
JuneHollow Earth #3
JulyThe Third Wish #1
AugustThe Third Wish #2
2003MayThe Soul of Venice
JulyDark Waters
AugustDr. Carp's Experiment
SeptemberNight Train
NovemberThere's Something Under My Bed
2004MarchThe PenanggalanBorn Again
Plague of Frogs #1
AprilPlague of Frogs #2
MayPlague of Frogs #3
JunePlague of Frogs #4
JulyThe Troll-WitchPlague of Frogs #5
AugustAnother Day at the Office
NovemberThe Dead #1
DecemberThe Dead #2
2005JanuaryThe Dead #3
FebruaryThe Dead #4
MarchThe Dead #5
JuneThe Ghoul
The Island #1
JulyThe Island #2
AugustThe Black Flame #1
SeptemberThe Black Flame #2
OctoberThe Black Flame #3
NovemberThe Black Flame #4
DecemberThe Black Flame #5
2006JanuaryThe Black Flame #6
FebruaryMakoma #1
MarchMakoma #2
AprilThe Universal Machine #1
MayThe Universal Machine #2
JuneThe Universal Machine #3
JulyThe Universal Machine #4
AugustThe Island
(Epilogue)The Universal Machine #5
DecemberThe Hydra and the Lion
2007MarchGarden of Souls #1
AprilGarden of Souls #2
MayDarkness Calls #1Garden of Souls #3
Darkness Calls #2
JuneDarkness Calls #3Garden of Souls #4
JulyDarkness Calls #4Garden of Souls #5
AugustDarkness Calls #5Killing Ground #1
They That Go Down to the Sea in Ships
SeptemberKilling Ground #2LOBSTER JOHNSON:
The Iron Prometheus #1
OctoberThe Vampire of PragueKilling Ground #3LOBSTER JOHNSON:
The Iron Prometheus #2
The Penanggalan
(Redrawn Page)
NovemberDarkness Calls #6Killing Ground #4LOBSTER JOHNSON:
The Iron Prometheus #3
DecemberKilling Ground #5LOBSTER JOHNSON:
The Iron Prometheus #4
2008January1946 #1LOBSTER JOHNSON:
The Iron Prometheus #5
February1946 #2The Drowning #1
March1946 #3The Drowning #2
Revival 1
April1946 #4The Drowning #3
Revival 2
MayDarkness Calls
(Epilogues)1946 #5The Drowning #4
Out of Reach
The MoleBishop Olek's Devil
JuneWar on Frogs #1The Drowning #5
The Ectoplasmic Man
JulyThe Crooked Man #1The Warning #1
AugustThe Crooked Man #2The Warning #2
SeptemberThe Crooked Man #3The Warning #3
OctoberIn the Chapel of MolochThe Warning #4
NovemberThe Warning #5WITCHFINDER:
Murderous Intent
DecemberThe Wild Hunt #1War on Frogs #2
2009JanuaryThe Wild Hunt #2The Black Goddess #1How Koshchei Became Deathless 1
FebruaryThe Wild Hunt #3The Black Goddess #2How Koshchei Became Deathless 2
MarchThe Wild Hunt #4The Black Goddess #3Baba Yaga's Feast
AprilThe Black Goddess #4
MayThe Black Goddess #5
JuneWar on Frogs #3
And What Shall I Find There?
July1947 #1WITCHFINDER:
In the Service of Angels #1
AugustThe Wild Hunt #51947 #2WITCHFINDER:
In the Service of Angels #2
SeptemberThe Wild Hunt #61947 #3WITCHFINDER:
In the Service of Angels #3
OctoberThe Wild Hunt #71947 #4The Haunted BoyWITCHFINDER:
In the Service of Angels #4
The Burial of Katharine Baker
NovemberThe Wild Hunt #81947 #5WITCHFINDER:
In the Service of Angels #5
DecemberThe Bride of HellWar on Frogs #4
2010JanuaryKing of Fear #1
FebruaryKing of Fear #2
MarchKing of Fear #3
AprilKing of Fear #4
Revival
(Extended Version)
MayHellboy in MexicoKing of Fear #5
JuneThe Abyssal Plain #1
JulyThe Storm #1The Abyssal Plain #2
AugustThe Storm #2HELL ON EARTH:
New World #1
SeptemberThe Storm #3HELL ON EARTH:
New World #2
OctoberThe Whittier LegacyHELL ON EARTH:
New World #3
NovemberDouble Feature of EvilHELL ON EARTH:
New World #4
DecemberThe Sleeping and The Dead #1HELL ON EARTH:
New World #5
2011JanuaryHELL ON EARTH:
Gods #1
FebruaryThe Sleeping and The Dead #2HELL ON EARTH:
Gods #2WITCHFINDER:
Lost and Gone Forever #1
MarchHELL ON EARTH:
Gods #3WITCHFINDER:
Lost and Gone Forever #2
HELL ON EARTH:
Seattle
AprilBuster Oakley Gets His WishThe Dead Remembered #1WITCHFINDER:
Lost and Gone Forever #3
MayBeing HumanThe Dead Remembered #2WITCHFINDER:
Lost and Gone Forever #4
JuneThe Fury #1The Dead Remembered #3WITCHFINDER:
Lost and Gone Forever #5
JulyThe Fury #2HELL ON EARTH:
Monsters #1
Casualties
AugustThe Fury #3HELL ON EARTH:
Monsters #2
SeptemberHELL ON EARTH:
Russia #1The Devil Does Not Jest #1
OctoberHELL ON EARTH:
Russia #2The Devil Does Not Jest #2
NovemberHouse of the Living DeadHELL ON EARTH:
Russia #3
DecemberHellboy versus the Aztec MummyHELL ON EARTH:
Russia #4
2012JanuaryHELL ON EARTH:
Russia #5LOBSTER JOHNSON:
The Burning Hand #1
FebruaryHELL ON EARTH:
The Long Death #1LOBSTER JOHNSON:
The Burning Hand #2
An Unmarked GraveLOBSTER JOHNSON:
Tony Masso's Finest Hour
MarchThe Fury
(Epilogue)HELL ON EARTH:
The Long Death #2LOBSTER JOHNSON:
The Burning Hand #3
HELL ON EARTH:
The Pickens County Horror #1
AprilHELL ON EARTH:
The Long Death #3LOBSTER JOHNSON:
The Burning Hand #4
HELL ON EARTH:
The Pickens County Horror #2
MayHELL ON EARTH:
The Devil's Engine #1LOBSTER JOHNSON:
The Burning Hand #5
HELL ON EARTH:
The Transformation of J.H. O'Donnell
JuneHELL ON EARTH:
The Devil's Engine #2
HELL ON EARTH:
Exorcism #1
JulyHELL ON EARTH:
The Devil's Engine #3
HELL ON EARTH:
Exorcism #2
AugustHELL ON EARTH:
The Return of the Master #1LOBSTER JOHNSON:
The Prayer of Neferu
SeptemberHELL ON EARTH:
The Return of the Master #2LOBSTER JOHNSON:
Caput Mortuum
October1948 #1
HELL ON EARTH #100:
The Return of the Master #3
November1948 #2
HELL ON EARTH #101:
The Return of the Master #4
DecemberHellboy in Hell #11948 #3
HELL ON EARTH #102:
The Return of the Master #5
2013JanuaryHellboy in Hell #2HELL ON EARTH #103:
The Abyss of Time #1
1948 #4
FebruaryHellboy in Hell #3HELL ON EARTH #104:
The Abyss of Time #2
1948 #5
MarchHellboy in Hell #4HELL ON EARTH #105:
A Cold Day in Hell #1Sledgehammer 44 #1
Vampire #1
AprilHELL ON EARTH #106:
A Cold Day in Hell #2ABE SAPIEN #1:
Dark and Terrible #1Sledgehammer 44 #2
Vampire #2
MayHELL ON EARTH #107:
Wasteland #1ABE SAPIEN #2:
Dark and Terrible #2LOBSTER JOHNSON:
Satan Smells a Rat
Vampire #3
JuneHELL ON EARTH #108:
Wasteland #2ABE SAPIEN #3:
Dark and Terrible #3
Vampire #4
JulyHELL ON EARTH #109:
Wasteland #3ABE SAPIEN #4:
The New Race of Man #1LOBSTER JOHNSON:
A Scent of Lotus #1
Vampire #5
AugustHELL ON EARTH #110:
Lake of Fire #1ABE SAPIEN #5:
The New Race of Man #2LOBSTER JOHNSON:
A Scent of Lotus #2
SeptemberHELL ON EARTH #111:
Lake of Fire #2
OctoberThe Midnight CircusHELL ON EARTH #112:
Lake of Fire #3ABE SAPIEN #6:
The Shape of Things to Come #1
NovemberHELL ON EARTH #113:
Lake of Fire #4ABE SAPIEN #7:
The Shape of Things to Come #2SLEDGEHAMMER 44:
Lightning War #1
DecemberHELLBOY IN HELL #5:
The Three Gold WhipsHELL ON EARTH #114:
Lake of Fire #5ABE SAPIEN #8
The Land of the DeadSLEDGEHAMMER 44:
Lightning War #2
Hellboy Gets Married 1
2014JanuaryHellboy Gets Married 2HELL ON EARTH #115:
The Reign of the Black Flame #1ABE SAPIEN #9:
To the Last Man #1SLEDGEHAMMER 44:
Lightning War #3
FebruaryHELL ON EARTH #116:
The Reign of the Black Flame #2ABE SAPIEN #10:
To the Last Man #2LOBSTER JOHNSON:
Get the Lobster #1
MarchThe Coffin ManHELL ON EARTH #117:
The Reign of the Black Flame #3ABE SAPIEN #11:
To the Last Man #3LOBSTER JOHNSON:
Get the Lobster #2
AprilHELL ON EARTH #118:
The Reign of the Black Flame #4LOBSTER JOHNSON:
Get the Lobster #3
MayHELLBOY IN HELL #6:
The Death CardHELL ON EARTH #119:
The Reign of the Black Flame #5ABE SAPIEN #12:
The Garden (I)WITCHFINDER:
Beware the Ape
JuneHELL ON EARTH #120:
The Devil's Wings #1ABE SAPIEN #13:
The HealerLOBSTER JOHNSON:
Get the Lobster #4
WITCHFINDER:
The Mysteries of Unland #1
JulyHELL ON EARTH #121:
The Devil's Wings #2ABE SAPIEN #14:
Visions, Dreams, and Fishin'WITCHFINDER:
The Mysteries of Unland #2
AugustHELL ON EARTH #122:
The Broken Equation #1ABE SAPIEN #15:
Lost LivesLOBSTER JOHNSON:
Get the Lobster #5
WITCHFINDER:
The Mysteries of Unland #3
SeptemberHELL ON EARTH #123:
The Broken Equation #2ABE SAPIEN #16:
Sacred Places #1WITCHFINDER:
The Mysteries of Unland #4
OctoberHELL ON EARTH #124:
GrindABE SAPIEN #17:
Sacred Places #2WITCHFINDER:
The Mysteries of Unland #5
NovemberHELL ON EARTH #125:
Flesh and Stone #1
DecemberHELLBOY AND THE B.P.R.D.:
1952 #1HELL ON EARTH #126:
Flesh and Stone #2ABE SAPIEN #18:
A Darkness so Great #1
2015JanuaryHELLBOY AND THE B.P.R.D.:
1952 #2HELL ON EARTH #127:
Flesh and Stone #3ABE SAPIEN #19:
A Darkness so Great #2
The Calm Before the Storm
FebruaryHELLBOY AND THE B.P.R.D.:
1952 #3HELL ON EARTH #128:
Flesh and Stone #4ABE SAPIEN #20:
A Darkness so Great #3
The Coffin Man 2: The Rematch
MarchHELLBOY AND THE B.P.R.D.:
1952 #4HELL ON EARTH #129:
Flesh and Stone #5ABE SAPIEN #21:
A Darkness so Great #4Frankenstein Underground #1
AprilHELLBOY AND THE B.P.R.D.:
1952 #5HELL ON EARTH #130:
Nowhere, Nothing, Never #1ABE SAPIEN #22:
A Darkness so Great #5Frankenstein Underground #2
MayHELL ON EARTH #131:
Nowhere, Nothing, Never #2Frankenstein Underground #3
JuneHELL ON EARTH #132:
Nowhere, Nothing, Never #3SubconsciousFrankenstein Underground #4
ABE SAPIEN #23:
The Ogopogo
JulyHELL ON EARTH #133:
Modern Prometheus #1ABE SAPIEN #24Frankenstein Underground #5
LOBSTER JOHNSON:
A Chain Forged in Life
AugustHELLBOY IN HELL #7:
The Hounds of Pluto #1HELL ON EARTH #134:
Modern Prometheus #2
SeptemberHELLBOY IN HELL #8:
The Hounds of Pluto #2
Stories Out of Continuity.
A number stories have featured Hellboy and related characters but are not a part of Hellboy continuity. Such stories include;
Numerous Hellboy guest appearances in other comics including;
John Byrne's Next Men #21 (Dec 1993)
Danger Unlimited #4 (May 1994) a 2 panel cameo
Shi/Cyblade: The Battle for Independents #1 (1995)
Savage Dragon #34 -35 , 41 (Dec 1996, Feb 1997, Sept 1997)
Painkiller Jane/Hellboy (Aug 1998)
Batman Hellboy Starman #1-2 (Jan-Feb 1999)
The Goon #7 (Jun 2004)
Ghost/Hellboy Special #1-2 (May-Jun 2005)
Hellboy/Beasts of Burden: Sacrifice (Oct 2010)
Hellboy Junior (Oct 1997, Oct-Nov 1999) showing the (mis)adventures of a Hellboy still in Hell before coming to earth
The Astromagnet (2002) a short story created as a promo for Hellboy Sourcebook and Role Playing Game
The Kabandha (Aug 2002) a short story printed in Hellboy Sourcebook and Role Playing Game.
Hellboy: Weird Tales #1-8 (Feb 2003 to Apr 2004, every two months) a collection of other writers' takes on Hellboy
Hellboy Animated comics (Oct 2006-Dec 2007) further expanding the Hellboy Animated world
Hellboy: The Golden Army (Jan 2008) a promotional tie-in for Hellboy II: The Golden Army
It is occasionally unclear whether a story should be considered in Canon. However, as a general rule, stories reprinted in a normal Hellboy or related Trade Paperback can safely be seen as within continuity, while those not reprinted, or reprinted in some other way can be assumed outside of continuity.
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215.Planetary system.
A planetary system is a set of gravitationally bound non-stellar objects in orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. The Sun together with its planetary system, which includes Earth, is known as the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
A total of 1909 exoplanets (in 1205 planetary systems, including 480 multiple planetary systems) have been identified as of 9 April 2015.
Of particular interest to astrobiology is the habitable zone of planetary systems where planets could have surface liquid water.
Historically, heliocentrism (the doctrine that the Sun is the centre of the universe) was opposed to geocentrism (placing the Earth at the center of the universe).
The notion of a heliocentric Solar System, with the Sun at the center, is possibly first suggested in the Vedic literature of ancient India, which often refer to the Sun as the "centre of spheres". Some interpret Aryabhatta's writings in ?ryabha??ya as implicitly heliocentric.
The idea was first proposed in western philosophy and Greek astronomy as early as the 3rd century BC by Aristarchus of Samos, but had received no support from most other ancient astronomers.
Discovery of the Solar System.
Main article: Discovery and exploration of the Solar System.
Heliocentric model of the Solar System in Copernicus' manuscript.
De revolutionibus orbium coelestium by Nicolaus Copernicus, published in 1543, was the first mathematically predictive heliocentric model of a planetary system. 17th-century successors Galileo Galilei, Johannes Kepler, and Isaac Newton developed an understanding of physics which led to the gradual acceptance of the idea that the Earth moves round the Sun and that the planets are governed by the same physical laws that governed the Earth.
Speculation on extrasolar planetary systems.
In the 16th century the Italian philosopher Giordano Bruno, an early supporter of the Copernican theory that the Earth and other planets orbit the Sun, put forward the view that the fixed stars are similar to the Sun and are likewise accompanied by planets. He was burned at the stake for his ideas by the Roman Inquisition.
In the 18th century the same possibility was mentioned by Isaac Newton in the "General Scholium" that concludes his Principia. Making a comparison to the Sun's planets, he wrote "And if the fixed stars are the centers of similar systems, they will all be constructed according to a similar design and subject to the dominion of One."
His theories gained traction through the 19th and 20th centuries despite a lack of supporting evidence. Long before their confirmation by astronomers, conjecture on the nature of planetary systems had been a focus of Search for extraterrestrial intelligence and has been a prevalent theme in fiction, particularly science fiction.
Detection of exoplanets.
The first confirmed detection of an exoplanet was in 1992, with the discovery of several terrestrial-mass planets orbiting the pulsar PSR B1257+12. The first confirmed detection of exoplanets of a main-sequence star was made in 1995, when a giant planet, 51 Pegasi b, was found in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has increased since then, particularly through advancements in methods of detecting extrasolar planets and dedicated planet finding programs such as the Kepler mission.
Planetary systems come from protoplanetary disks that form around stars as part of the process of star formation.
During formation of a system much material is gravitationally scattered into far-flung orbits and some planets are ejected completely from the system becoming rogue planets.
Evolved systems.
High-mass stars.
Planets orbiting pulsars have been discovered, and pulsars are the remnants of the supernova explosions of high-mass stars. A planetary system that existed before the supernova would likely be mostly destroyed ? planets would either evaporate, be pushed off of their orbits by the masses of gas from the exploding star, or the sudden loss of most of the mass of the central star would see them escape the gravitational hold of the star, or in some cases the supernova would kick the pulsar itself out of the system at high velocity so any planets that had survived the explosion would be left behind as free-floating objects. Planets found around pulsars may have formed as a result of pre-existing stellar companions that were almost entirely evaporated by the supernova blast, leaving behind planet-sized bodies. Alternatively, planets may form in an accretion disk of fallback matter surrounding a pulsar. Fallback disks of matter that failed to escape orbit during a supernova may also form planets around black holes.
Lower-mass stars.
As stars evolve and turn into red giants, asymptotic giant branch stars and planetary nebulae they engulf the inner planets, evaporating or partially evaporating them depending on how massive they are. As the star loses mass, planets that are not engulfed move further out from the star.
If an evolved star is in a binary or multiple system then the mass it loses can transfer to another star, creating new protoplanetary disks and second- and third-generation planets which may differ in composition from the original planets which may also be affected by the mass transfer.
Planets in evolved binary systems, Hagai B. Perets, 13 Jan 2011
Can Planets survive Stellar Evolution?, Eva Villaver, Mario Livio, Feb 2007
The Orbital Evolution of Gas Giant Planets around Giant Stars, Eva Villaver, Mario Livio, 13 Oct 2009
On the survival of brown dwarfs and planets engulfed by their giant host star, Jean-Claude Passy, Mordecai-Mark Mac Low, Orsola De Marco, 2 Oct 2012
Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs, Alexander James Mustill, Eva Villaver, 5 Dec 2012
The Solar System consists of an inner region of small rocky planets and outer region of large gas giants however other planetary systems can have quite different architectures. Many systems with a hot Jupiter gas giant very close to the star have been found. Theories, such as planetary migration or scattering, have been proposed for the formation of large planets close to their parent stars. At present, few systems have been found to be analogous to the Solar System with terrestrial planets close to the parent star. More commonly, systems consisting of multiple Super-Earths have been detected.
Orbital properties.
Unlike the Solar System, which has orbits that are nearly circular, many of the known planetary systems display much higher orbital eccentricity. An example of such a system is 16 Cygni.
Mutual inclination.
The mutual inclination between two planets is the angle between their orbital planes. Many compact systems with multiple close-in planets interior to the equivalent orbit of Venus are expected to have very low mutual inclinations, so the system (at least the close-in part) would be even flatter than the solar system. Captured planets could be captured into any arbitrary angle to the rest of the system. The only system where mutual inclinations have actually been measured is the Upsilon Andromedae system: the planets, c and d, have a mutual inclination of about 30 degrees.
Orbital dynamics.
Planetary systems can be categorized according to their orbital dynamics as resonant, non-resonant-interacting, hierarchical, or some combination of these. In resonant systems the orbital periods of the planets are in integer ratios. The Kepler-223 system contains four planets in an 8:6:4:3 orbital resonance. Giant planets are found in mean-motion resonances more often than smaller planets. In interacting systems the planets orbits are close enough together that they perturb the orbital parameters. The Solar System could be described as weakly interacting. In strongly interacting systems Kepler's laws do not hold. In hierarchical systems the planets are arranged so that the system can be gravitationally considered as a nested system of two-bodies, e.g. in a star with a close-in hot jupiter with another gas giant much further out, the star and hot jupiter form a pair that appears as a single object to another planet that is far enough out.
Other, as yet unobserved, orbital possibilities include: double planets; various co-orbital planets such as quasi-satellites, trojans and exchange orbits; and interlocking orbits maintained by precessing orbital planes.
Extrasolar Binary Planets I: Formation by tidal capture during planet-planet scattering, H. Ochiai, M. Nagasawa, S. Ida, 26 Jun 2014
Disruption of co-orbital (1:1) planetary resonances during gas-driven orbital migration, Arnaud Pierens, Sean Raymond, 19 May 2014
Captured planets.
Free-floating planets in open clusters have similar velocities to the stars and so can be recaptured. They are typically captured into wide orbits between 100 and 105 AU. The capture efficiency decreases with increasing cluster size, and for a given cluster size it increases with the host/primary mass. It is almost independent of the planetary mass. Single and multiple planets could be captured into arbitrary unaligned orbits, non-coplanar with each other or with the stellar host spin, or pre-existing planetary system. Some planet?host metallicity correlation may still exist due to the common origin of the stars from the same cluster. Planets would be unlikely to be captured around neutron stars because these are likely to be ejected from the cluster by a pulsar kick when they form. Planets could even be captured around other planets to form free-floating planet binaries. After the cluster has dispersed some of the captured planets with orbits larger than 106 AU would be slowly disrupted by the galactic tide and likely become free-floating again through encounters with other field stars or giant molecular clouds.
Number of planets, relative parameters and spacings.
The spacings between orbits vary widely amongst the different systems discovered by the Kepler spacecraft.
On The Relative Sizes of Planets Within Kepler Multiple Candidate Systems, David R. Ciardi et al. 9 Dec 2012
The Kepler Dichotomy among the M Dwarfs: Half of Systems Contain Five or More Coplanar Planets, Sarah Ballard, John Asher Johnson, 15 Oct 2014
Exoplanet Predictions Based on the Generalised Titius-Bode Relation, Timothy Bovaird, Charles H. Lineweaver, 1 Aug 2013
The Solar System and the Exoplanet Orbital Eccentricity - Multiplicity Relation, Mary Anne Limbach, Edwin L. Turner, 9 Apr 2014
The period ratio distribution of Kepler's candidate multiplanet systems, Jason H. Steffen, Jason A. Hwang, 11 Sep 2014
Are Planetary Systems Filled to Capacity? A Study Based on Kepler Results, Julia Fang, Jean-Luc Margot, 28 Feb 2013
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216.Proportion of stars with planets.
There is at least one planet on average per star. Around 1 in 5 Sun-like stars[a] have an "Earth-sized"[b] planet in the habitable zone.
Most stars have planets but exactly what proportion of stars have planets is uncertain because not all planets can yet be detected. The radial-velocity method and the transit method (which between them are responsible for the vast majority of detections) are most sensitive to large planets in small orbits. Thus many known exoplanets are "hot Jupiters": planets of Jovian mass or larger in very small orbits with periods of only a few days. A 2005 survey of radial-velocity-detected planets found that about 1.2% of Sun-like stars have a hot jupiter, where "Sun-like star" refers to any main-sequence star of spectral classes late-F, G, or early-K without a close stellar companion. This 1.2% is more than double the frequency of hot jupiters detected by the Kepler spacecraft, which may be because the Kepler field of view covers a different region of the Milky Way where the metallicity of stars is different. It is further estimated that 3% to 4.5% of Sun-like stars possess a giant planet with an orbital period of 100 days or less, where "giant planet" means a planet of at least 30 Earth masses.
It is known that small planets (of roughly Earth-like mass or somewhat larger) are more common than giant planets. It also appears that there are more planets in large orbits than in small orbits. Based on this, it is estimated that perhaps 20% of Sun-like stars have at least one giant planet whereas at least 40% may have planets of lower mass. A 2012 study of gravitational microlensing data collected between 2002 and 2007 concludes the proportion of stars with planets is much higher and estimates an average of 1.6 planets orbiting between 0.5?10 AU per star in the Milky Way, the authors of this study conclude that "stars are orbited by planets as a rule, rather than the exception". In November 2013 it was announced that 22±8% of Sun-like[a] stars have an Earth-sized[b] planet in the habitable[c] zone.
Whatever the proportion of stars with planets, the total number of exoplanets must be very large. Because the Milky Way has at least 200 billion stars, it must also contain tens or hundreds of billions of planets.
Type of star, spectral classification.
See also planets orbiting Herbig Ae/Be stars, T Tauri stars, Subgiants, Yellow giants, Red giants, B-type stars, A-type stars, Subdwarf B stars, F-type stars, G-type stars, K-type stars, Red dwarfs, Brown dwarfs, White dwarfs, or Pulsars.
The Morgan-Keenan spectral classification.
Most known exoplanets orbit stars roughly similar to the Sun, that is, main-sequence stars of spectral categories F, G, or K. One reason is that planet-search programs have tended to concentrate on such stars. In addition, statistical analyses indicate that lower-mass stars (red dwarfs, of spectral category M) are less likely to have planets massive enough to be detected by the radial-velocity method. Nevertheless, several tens of planets around red dwarfs have been discovered by the Kepler spacecraft by the transit method, which can detect smaller planets.
Stars of spectral category A typically rotate very quickly, which makes it very difficult to measure the small Doppler shifts induced by orbiting planets because the spectral lines are very broad. However, this type of massive star eventually evolves into a cooler red giant that rotates more slowly and thus can be measured using the radial-velocity method. A few tens of planets have been found around red giants.
Observations using the Spitzer Space Telescope indicate that extremely massive stars of spectral category O, which are much hotter than the Sun, produce a photo-evaporation effect that inhibits planetary formation. When the O-type star goes supernova any planets that had formed would become free-floating due to the loss of stellar mass unless the natal kick of the resulting remnant pushes it in the same direction as an escaping planet. Fallback disks of matter that failed to escape orbit during a supernova may form planets around neutron stars and black holes.
Doppler surveys around a wide variety of stars indicate about 1 in 6 stars having twice the mass of the Sun are orbited by one or more Jupiter-sized planets, vs. 1 in 16 for Sun-like stars and only 1 in 50 for red dwarfs. On the other hand, microlensing surveys indicate that long-period Neptune-mass planets are found around 1 in 3 red dwarfs. Kepler Space Telescope observations of planets with up to one year periods show that occurrence rates of Earth- to Neptune-sized planets (1 to 4 Earth radii) around M, K, G, and F stars are successively higher towards cooler, less massive stars.
At the low-mass end of star-formation are sub-stellar objects that don't fuse hydrogen: the brown dwarfs and sub-brown dwarfs, of spectral classification L,T and Y. Planets and protoplanetary disks have been discovered around brown dwarfs, and disks have been found around sub-brown dwarfs (e.g. OTS 44).
Rogue planets ejected from their system could retain a system of satellites.
Metallicity.
Stars with a higher metallicity than the Sun are more likely to have planets, especially giant planets, than stars with lower metallicity.
Ordinary stars are composed mainly of the light elements hydrogen and helium. They also contain a small proportion of heavier elements, and this fraction is referred to as a star's metallicity (even if the elements are not metals in the traditional sense), denoted [m/H] and expressed on a logarithmic scale where zero is the Sun's metallicity.
A 2012 study of the Kepler spacecraft data found that smaller planets, with radii smaller than Neptune's were found around stars with metallicities in the range ?0.6 < [m/H] < +0.5 (about four times less than that of the Sun to three times more),[d] whereas larger planets were found mostly around stars with metallicities at the higher end of this range (at solar metallicity and above). In this study small planets occurred about three times as frequently as large planets around stars of metallicity greater than that of the Sun, but they occurred around six times as frequently for stars of metallicity less than that of the Sun. The lack of gas giants around low-metallicity stars could be because the metallicity of protoplanetary disks affects how quickly planetary cores can form and whether they accrete a gaseous envelope before the gas dissipates. However, Kepler can only observe planets very close to their star and the detected gas giants probably migrated from further out, so a decreased efficiency of migration in low-metallicity disks could also partly explain these findings.
A 2014 study found that not only giant planets, but planets of all sizes have an increased occurrence rate around metal-rich stars compared to metal-poor stars, although the larger the planet, the greater this increase as the metallicity increases. The study divided planets into three groups based on radius: gas giants, gas dwarfs, and terrestrial planets with the dividing lines at 1.7 and 3.9 Earth radii. For these three groups the planet occurrence rates are 9.30, 2.03, and 1.72 times higher for metal-rich stars than for metal-poor stars, respectively. There is a bias against detecting smaller planets because metal-rich stars tend to be larger, making it more difficult to detect smaller planets, which means that these increases in occurrence rates are lower limits.
It has also been shown that stars with planets are more likely to be deficient in lithium.
Multiple stars.
Stellar multiplicity increases with stellar mass: the likelihood of stars being in multiple systems is about 25% for red dwarfs, about 45% for Sun-like stars, and rises to about 80% for the most massive stars. Of the multiple stars about 75% are binaries and the rest are higher-order multiplicities.
Some planets have been discovered orbiting one member of a binary star system (e.g. 55 Cancri, possibly Alpha Centauri Bb), and several circumbinary planets have been discovered which orbit around both members of binary star (e.g. PSR B1620-26 b, Kepler-16b). A few planets in triple star systems are known (e.g. 16 Cygni Bb)[41] and one in the quadruple system Kepler 64.
The Kepler results indicate circumbinary planetary systems are relatively common (as of October 2013 the spacecraft had found seven circumbinary planets out of roughly 1000 eclipsing binaries searched). One puzzling finding is that although half of the binaries have an orbital period of 2.7 days or less, none of the binaries with circumbinary planets have a period less than 7.4 days. Another surprising Kepler finding is circumbinary planets tend to orbit their stars close to the critical instability radius (theoretical calculations indicate the minimum stable separation is roughly two to three times the size of the stars' separation).
In 2014, from statisitcal studies of searches for companion stars, it was inferred that around half of exoplanet host stars have a companion star, usually within 100AU. This means that many exoplanet host stars that were thought to be single are binaries, so in many cases it is not known which of the stars a planet actually orbits, and the published parameters of transiting planets could be significantly incorrect because the planet radius and distance from star are derived from the stellar parameters. Follow-up studies with imaging (such as speckle imaging) are needed to find or rule out companions (and radial velocity techniques would be required to detect binaries really close together) and this has not yet been done for most exoplanet host stars. Examples of known binary stars where it is not known which of the stars a planet orbits are Kepler-132 and Kepler-296.
Open clusters.
Most stars form in open clusters, but very few planets have been found in open clusters and this led to the hypothesis that the open-cluster environment hinders planet formation. However, a 2011 study concluded that there have been an insufficient number of surveys of clusters to make such a hypothesis. The lack of surveys was because there are relatively few suitable open clusters in the Milky Way. Recent discoveries of both giant planets and low-mass planets in open clusters are consistent with there being similar planet occurrence rates in open clusters as around field stars.
The open cluster NGC 6811 contains two known planetary systems Kepler-66 and Kepler-67.
Age.
The Ages of Stars, David R. Soderblom, 31 Mar 2010
Towards asteroseismically calibrated age-rotation-activity relations for Kepler solar-like stars, R.A. Garcia et al. 27 Mar 2014
Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited, Alexandra Fogtmann-Schulz et al. 5 Dec 2013
AsteroseismologyEdit
The importance of asteroseismology in exoplanetary science, F Borsa, E Poretti - sait.oat.ts.astro.it
What asteroseismology can do for exoplanets: Kepler-410A b is a Small Neptune around a bright star, in an eccentric orbit consistent with low obliquity, Vincent Van Eylen et al. 17 Dec 2013
Pulsations and planets: the asteroseismology-extrasolar-planet connection, Sonja Schuh, 19 May 2010
Stellar activityEdit
How stellar activity affects the size estimates of extrasolar planets, S. Czesla, K. F. Huber, U. Wolter, S. Schröter, J. H. M. M. Schmitt, 19 Jun 2009
Hot Jupiters and stellar magnetic activity, A. F. Lanza, 20 May 2008
Extrasolar Giant Planets and X-ray Activity, Vinay L. Kashyap, Jeremy J. Drake, Steven H. Saar, 21 Jul 2008
Mass loss of "Hot Jupiters"?Implications for CoRoT discoveries. Part I: The importance of magnetospheric protection of a planet against ion loss caused by coronal mass ejections, Khodachenko et al. April 2007
The habitable zone around a star is the region where the temperature is just right to allow liquid water to exist on a planet; that is, not too close to the star for the water to evaporate and not too far away from the star for the water to freeze. The heat produced by stars varies depending on the size and age of the star so that the habitable zone can be at different distances. Also, the atmospheric conditions on the planet influence the planet's ability to retain heat so that the location of the habitable zone is also specific to each type of planet.
Habitable zones have usually been defined in terms of surface temperature, however over half of Earth's biomass is from subsurface microbes, and the temperature increases as you go deeper underground, so the subsurface can be conducive for life when the surface is frozen and if this is considered, the habitable zone extends much further from the star, even rogue planets could have liquid water at sufficient depths underground.
Venus zone.
The Venus zone is the region around a star where a terrestrial planet would have runaway greenhouse conditions like Venus, but not so near the star that the atmosphere completely evaporates. As with the habitable zone, the location of the Venus zone depends on several factors including the type of star and properties of the planets such as mass, rotation rate and atmospheric clouds. Studies of the Kepler spacecraft data indicate that 32% of red dwarfs have potentially Venus-like planets based on planet size and distance from star, rising to 45% for K-type and G-type stars. Several candidates have been identified but spectroscopic follow-up studies of their atmospheres will be required to see if they really are like Venus.
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