Seznam potenciálně obyvatelných exoplanet

Seznam potenciálně obyvatelných exoplanet je seznam nedávno objevených exoplanet, založený na katalogu Habitabilních exoplanet (HEC) a dat NASA. Kvůli úrovně dnešních technologií je omezený kvalitou a přesností dat. [1][2]

Potenciálně obyvatelná exoplaneta je planeta mimo naši sluneční soustavu, která není plynnou a má teoreticky vhodné podmínky pro vznik mimozemského života, byť i velmi primitivního. Míru obyvatelnosti ovlivňuje nesčetné množství faktorů a jejich vzájemné spolupůsobení. Hlavním kritériem je, aby se těleso nacházelo v tzv. obyvatelné zóně (ekosféře), tedy v takové vzdálenosti od mateřské hvězdy, aby se voda na povrchu udržela v kapalném skupenství. Mezi další faktory patří například množství přijímaného záření, přítomnost atmosféry (plus její složení), spektrální typ mateřské hvězdy aj.

Po přezkoumání údajů se v roce 2015 došlo k závěru, že mezi tři nejvhodnějšími kandidáty patří: Kepler-62f, Kepler-186f a Kepler-442b.

Legenda pojmů

  • Planeta – Katalogové označení planety.
  • Hmotnost (M⊕) – Hmotnost planety v jednotkách Země. Jedná se o hrubý odhad.
  • Poloměr (R⊕) – Poloměr planety v jednotkách Země.
  • Zářivý tok (F⊕) – Množství energie, kterou přijímá planeta od své mateřské hvězdy v jednotkách Země.
  • Teplota (°C) – Teoretická teplota na povrchu planety. Jedná se o hrubý odhad, jelikož závisí na přítomnosti atmosféry, její hustotě, složení, proudění aj.
  • Doba oběhu (pozemské dny) – Doba, za kterou planeta svojí mateřskou hvězdu oběhne.
  • Vzdálenost (ly) – Vzdálenost exoplanety od Země. 1 ly je vzdálenost, kterou světlo při své rychlosti ~300 000 km/s uletí za jeden pozemský rok. Pro příklad: Země je od Slunce vzdálená 8 světelných minut, Pluto 5 světelných hodin a nejbližší hvězdný systém (Proxima Centauri) 4,22 světelných let. Průměr celé naší Galaxie činí 150–200 tisíc světelných let.
  • Rok objevu – Rok, kdy byla planeta objevená.
  • Hvězda – Katalogové označení mateřské hvězdy.
  • Souhvězdí – Pozorována ze Země, tedy do kterého souhvězdí spadá mateřská hvězda.
  • Typ hvězdySpektrální klasifikace. Slunce patří do třídy G. Do třídy K a M patří menší, chladnější a déle žijící hvězdy. Naopak do třídy F, A, B a O patří větší, teplejší a krátce žijící hvězdy. Ty pro vznik života a pro jeho další vývoj nejsou vhodné kvůli svému staří: F – 1 miliarda let, O – 10 milionů let (život na Zemi potřeboval 3,5 miliardy let, aby se vyvinul do dnešní formy).
Přehled obyvatelných planet a jejich mateřských hvězd.
Potvrzené exoplanety v obyvatelné zóně.
(Kepler-62e, Kepler-62f, Kepler-186f, Kepler-296e, Kepler-296f, Kepler-438b, Kepler-440b, Kepler-442b)
Potvrzené exoplanety v obyvatelné zóně, přiřazené ke spektrálnímu typu své mateřské hvězdy.

Seznam

Seznam exoplanet v obyvatelné zóně

Je seznam planet, jež se zřejmě nacházejí v obyvatelné zóně. Hodnoty jsou pro lepší orientaci na barevném pozadí. Čím je daná hodnota bližší té pozemské, tím je zelenější. Neplatí však u sloupce "Typ hvězdy".

PlanetaHmotnost (M⊕)Poloměr (R⊕)Zářivý tok (F⊕)Teplota (°C)Doba oběhu (dny)Vzdálenost (ly)Rok objevuMateřská hvězdaSouhvězdíTyp hvězdyZdroje
Země1,001,001,0013,853650-Slunce-G2V-
Proxima Centauri b≥ 1,271,10,65-3911,194,22013Proxima CentauriKentaurM6Ve[3][4][5][6]
Gliese 667 Cc≥ 3,81,50,88428,1423,622011Gliese 667 CŠtírM3V[7][8]
Kepler-442b2,31,340,7-40112,311 291,62015Kepler-442LyraK?V[9]
Kepler-452b4,71,571,11-8384,81 4022015Kepler-452LabuťG2V[10][11][12][13]
Wolf 1061c≥ 4,31,61,36217,913,82015Wolf 1061HadonošM3V[14][15][16][17]
Kepler-1229b2,71,40,49-6086,87692016Kepler-1229bLabuťM?V[18]
Kapteyn b≥ 4,81,60,43-6848,6132014Kapteynova hvězdaMalířsdM1[19][20]
Kepler-62f2,81,410,39-29267,2911 2002013Kepler-62LyraK2V[21][22][23][24]
Kepler-186f1,51,170,29-85129,955612014Kepler-186LabuťM1V[25][26][27][28]
Luyten b2,89-1,06-2418,6512,362017Luytenova hvězdaMalý pesM3.5V[29][30][31]
Trappist - 1d0,300,781,04-154,05392016TRAPPIST - 1VodnářM8V[32][33]
Trappist - 1e0,770,910,67-436,1392016TRAPPIST - 1VodnářM8V[34][35][33]
Trappist - 1f0,931,050,38-739,2392016TRAPPIST - 1VodnářM8V[36][37][33]
TRAPPIST-1g1,151,150,26-9112,4392017TRAPPIST - 1VodnářM8V[38][39][33]
LHS 1140 b6,61,430,46-4325402017LHS 1140VelrybaM4.5V[40][41][42][43]
Kepler-1638b61,61,1731259,3652 491,832016Kepler-1638LabuťG4V[44]
Teegarden c1,11-0,37-11,412,582019TeegardenBeranM7V[45]

Seznam exoplanet na kraji obyvatelné zóny

Je seznam planet, u kterých je vzhledem k jejich zjištěným parametrům menší pravděpodobnost, že se jedná o kamenné planety, jež jsou schopny na svém povrchu udržet vodu v kapalném skupenství.

PlanetaHmotnost (M⊕)Poloměr (R⊕)Zářivý tok (F⊕)Teplota (°C)Doba oběhu (dny)Vzdálenost (ly)Rok objevuHvězdaSouhvězdíTyp hvězdyZdroje
Kepler-296e3,31,51,226434,17372014Kepler-296DrakK7V[46]
Kepler-62e4,51,61,10-3122,41 2002013Kepler-62LyraK2V[47][48]
Gliese 832 c≥ 5,41,71-1835,7162014Gliese 832JeřábM2V[49][50]
K2-3d11,11,51,462744,61372015K2-3LevM0V[51][52]
Kepler-1544b6,61,80,9-25168,81 1382016Kepler-1544LabuťK2V[53]
Kepler-283c71,80,9-2592,71 7412014Kepler-283LabuťK5V[54]
Tau Ceti e≥ 3,931,61,6112163122012Tau CetiVelrybaG8.5V[55][56]
Gliese 180 c≥ 6,41,80,79-3424,3382014Gliese 180EridanM2V[57]
Kepler-440b7,71,91,430101,18512015Kepler-440LabuťK6V[58]
Gliese 180 b≥ 8,31,91,23-517,4382014Gliese 180EridanM2V[59]
HD 40307 g7,11,80,68-46197,8422012HD 40307MalířK2.5V[60][61]
Gliese 163 c≥ 7,31,80,66-2025,6492012Gliese 163MečounM3.5V[62][63]
K2-18 b16,52,20,94-132,91112015K2-18LevM2.8V[64][65]
Kepler-61b13,82,21,27-859,91 0632013Kepler-64bLabuťK7V[66]
Kepler-443b19,52,30,89-26177,72 5402015Kepler-443LabuťK3V[67]
Kepler-22b20,42,221,11-11289,96192011Kepler-22LabuťG5V[68][69]
Gliese 422 b≥ 9,920,68-4226,2412014Gliese 422Lodní kýlM3.5V[70]
K2-9b16,82,21,382618,43592015K2-9PannaM?V[71]
Gliese 3293 c≥ 8,61,90,6-5048,1592014Gliese 3293EridanM2.5V[72]
Kepler 298d26,82,51,29-277,51 5452014Kepler 298DrakK5V[73]
Kepler-174d14,82,20,43-67247,41 1742014Kepler-174LyraK3V[74]
Kepler-296f6,11,80,34-3763,37372014Kepler-296DrakK7V[75]
Gliese 682 c≥ 8,71,90,37-7557,3172014Gliese 682ŠtírM3.5V[76]
KOI-4427 b7,41,80,24-94147,77822015KOI-4427LyraM0V[77]
Kepler-1090b16,82,31,2-6198,72 2892016Kepler-1090LabuťK0V[78]
Ross 128 b≥ 1,51,11,3879,8711,032017ROSS 128PannaM4V[79][80][81]
HD 20794 e4,77---33120201782 G. EridaniEridanG8V[82]
Gliese 625 b2,82---14,6321,32017Gliese 625DrakM2V[83]
HD 219134 g> 10,82,4-2594,221,352015HD 219134KasiopejaK3V[84][85]
Teegarden b1,05-1,15-4,9112,582019TeegardenBeranM7V[86][87]

Galerie

Odkazy

Reference

V tomto článku byl použit překlad textu z článku List of potentially habitable exoplanets na anglické Wikipedii.

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Související články

Média použitá na této stránce

Kepler22b-artwork.jpg
This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's habitable zone -- the region around a star where liquid water, a requirement for life on Earth, could persist. The planet is 2.4 times the size of Earth, making it the smallest yet found to orbit in the middle of the habitable zone of a star like our sun. Scientists do not yet know if the planet has a predominantly rocky, gaseous or liquid composition. It's possible that the world would have clouds in its atmosphere, as depicted here in the artist's interpretation.
Artist's impression of the planet orbiting Proxima Centauri.jpg
(c) ESO/M. Kornmesser, CC BY 4.0
This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.
PIA19827-Kepler-SmallPlanets-HabitableZone-20150723.jpg
PIA19827: Kepler's Small Habitable Zone Planets

http://photojournal.jpl.nasa.gov/catalog/PIA19827

Of the 1,030 confirmed planets from Kepler, a dozen are less than twice the size of Earth and reside in the habitable zone of their host stars. In this diagram, the sizes of the exoplanets are represented by the size of each sphere. These are arranged by size from left to right, and by the type of star they orbit, from the M stars that are significantly cooler and smaller than the sun, to the K stars that are somewhat cooler and smaller than the sun, to the G stars that include the sun. The sizes of the planets are enlarged by 25 times compared to the stars. The Earth is shown for reference.

NASA Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with JPL at the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

More information about the Kepler mission is at http://www.nasa.gov/kepler.

More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov.
Kepler-452b artist concept.jpg
An artist's concept depicting one possible appearance of the planet Kepler-452b, the first near-Earth-size world to be found in the habitable zone of a star that is similar to our sun.
This artist's concept depicts Kepler-62f.jpg
This artist's concept depicts Kepler-62f, a super-Earth-size planet in the habitable zone of its star.
Gliese 667.jpg
Autor: ESO/L. Calçada, Licence: CC BY 4.0
The 6-Earth-mass exoplanet Gliese 667Cb orbits its low-mass host star at a distance equal to only 1/20th of the Earth–Sun distance. The host star Gliese 667C is a companion to two other low-mass stars, which are seen here in the distance.
KeplerExoplanets-NearEarthSize-HabitableZone-20150106.png
NASA News

January 6, 2015

http://www.jpl.nasa.gov/news/news.php?release=2015-003

NASA's Kepler Marks 1,000th Exoplanet Discovery, Uncovers More Small Worlds in Habitable Zones

Of the more than 1,000 verified planets found by NASA's Kepler, eight are less than twice Earth-size and in their stars' habitable zone. All eight orbit stars cooler and smaller than our sun. The search continues for Earth-size habitable zone worlds around sun-like stars.


How many stars like our sun host planets like our Earth? NASA's Kepler Space Telescope continuously monitored more than 150,000 stars beyond our solar system, and to date has offered scientists an assortment of more than 4,000 candidate planets for further study -- the 1,000th of which was recently verified.

Using Kepler data, scientists reached this millenary milestone after validating that eight more candidates spotted by the planet-hunting telescope are, in fact, planets. The Kepler team also has added another 554 candidates to the roll of potential planets, six of which are near-Earth-size and orbit in the habitable zone of stars similar to our sun.

Three of the newly-validated planets are located in their distant suns' habitable zone, the range of distances from the host star where liquid water might exist on the surface of an orbiting planet. Of the three, two are likely made of rock, like Earth.

"Each result from the planet-hunting Kepler mission's treasure trove of data takes us another step closer to answering the question of whether we are alone in the universe," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate at the agency's headquarters in Washington. "The Kepler team and its science community continue to produce impressive results with the data from this venerable explorer."

To determine whether a planet is made of rock, water or gas, scientists must know its size and mass. When its mass can't be directly determined, scientists can infer what the planet is made of based on its size.

Two of the newly validated planets, Kepler-438b and Kepler-442b, are less than 1.5 times the diameter of Earth. Kepler-438b, 475 light-years away, is 12 percent bigger than Earth and orbits its star once every 35.2 days. Kepler-442b, 1,100 light-years away, is 33 percent bigger than Earth and orbits its star once every 112 days.

Both Kepler-438b and Kepler-442b orbit stars smaller and cooler than our sun, making the habitable zone closer to their parent star, in the direction of the constellation Lyra. The research paper reporting this finding has been accepted for publication in The Astrophysical Journal.

"With each new discovery of these small, possibly rocky worlds, our confidence strengthens in the determination of the true frequency of planets like Earth," said co-author Doug Caldwell, SETI Institute Kepler scientist at NASA's Ames Research Center at Moffett Field, California. "The day is on the horizon when we'll know how common temperate, rocky planets like Earth are."

With the detection of 554 more planet candidates from Kepler observations conducted May 2009 to April 2013, the Kepler team has raised the candidate count to 4,175. Eight of these new candidates are between one to two times the size of Earth, and orbit in their sun's habitable zone. Of these eight, six orbit stars that are similar to our sun in size and temperature. All candidates require follow-up observations and analysis to verify they are actual planets.

"Kepler collected data for four years -- long enough that we can now tease out the Earth-size candidates in one Earth-year orbits," said Fergal Mullally, SETI Institute Kepler scientist at Ames who led the analysis of a new candidate catalog. "We're closer than we've ever been to finding Earth twins around other sun-like stars. These are the planets we're looking for."

These findings also have been submitted for publication in The Astrophysical Journal Supplement.

Work is underway to translate these recent discoveries into estimates of how often rocky planets appear in the habitable zones of stars like our sun, a key step toward NASA's goal of understanding our place in the universe.

Scientists also are working on the next catalog release of Kepler's four-year data set. The analysis will include the final month of data collected by the mission and also will be conducted using sophisticated software that is more sensitive to the tiny telltale signatures of small Earth-size planets than software used in the past.

Ames is responsible for Kepler's mission operations, ground system development and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colorado, developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate in Washington.

For more information about the Kepler mission, visit:

http://www.nasa.gov/kepler