View source for Kepler-10b

{{Short description|Terrestrial exoplanet orbiting Kepler-10}}
{{good article}}

{{Infobox planet
| name                     = Kepler-10b
| image                    = Exoplanet Comparison Kepler-10 b.png
| caption                  = Size comparison of Kepler-10b with Earth
| discovery_ref = <ref name="Batalha2011"/>
| discoverer               = Batalha ''et al.''
| discovered               = January 10, 2011
| discovery_method         = [[Transit method|Transit]] ([[Kepler Mission]])
| apsis                    = astron
| semimajor                = 0.01684 {{±|0.00032|0.00034}}<ref name="Batalha2011"/> [[astronomical unit|AU]]
| eccentricity             = 0<ref name="Batalha2011"/>
| period                   = 0.837495<ref name="Batalha2011"/> [[day|d]]<br>20.0999 [[hour|h]]
| inclination              = 84.4<ref name="Batalha2011"/>
| semi-amplitude           = 3.3 {{±|0.8|1.0}}<ref name="Batalha2011"/>
| star                     = [[Kepler-10]]<ref name="datatable"/>
| mean_radius              = {{val|1.47|0.03}}<ref name=Brinkman/> {{earth radius|link=y}}
| mass                     = {{val|3.58|0.33}}<ref name=Brinkman/> {{Earth mass|link=y}}
| density                  = {{val|6.46|0.73}} g/cm<sup>3</sup><ref name="Weiss2016"/>
| surface_grav             = {{convert|15|m/s2|lk=on|abbr=on}}<ref name="harps"/>
| albedo                   = 0.5
| single_temperature       = {{convert|1833|K|C F}} (day side) <br> {{convert|50|K|C F}} (night side)<ref>{{Cite journal |last=Rouan |first=D. |last2=Deeg |first2=H. J. |last3=Demangeon |first3=O. |last4=Samuel |first4=B. |last5=Cavarroc |first5=C. |last6=Fegley |first6=B. |last7=Léger |first7=A. |date=2011 |title=The orbital phases and secondary transit of Kepler-10b - A physical interpretation based on the ''Lava-ocean'' planet model |journal=The Astrophysical Journal |volume=741 |issue=2 |pages=L30 |arxiv=1109.2768 |bibcode=2011ApJ...741L..30R |doi=10.1088/2041-8205/741/2/L30}}</ref>
}}
'''Kepler-10b''' is the first confirmed [[terrestrial planet]] to have been discovered outside the [[Solar System]] by the Kepler Space Telescope.<ref name= "BBCNews"/> Discovered after several months of data collection during the course of the [[NASA]]-directed [[Kepler Mission]], which aims to discover [[Earth]]-like planets [[transit method|crossing in front of]] their host stars, the planet's discovery was announced on January 10, 2011. Kepler-10b has a mass of 3.72±0.42 [[Earth mass]]es and a radius of 1.47 [[Earth radius|Earth radii]]. However, it lies extremely close to its star, [[Kepler-10]], and as a result is too hot to support life as we know it. Its existence was confirmed using measurements from the [[W.M. Keck Observatory]] in Hawaii.

==Nomenclature and history==
[[Kepler-10]], the star that hosts Kepler-10b, is located 560 [[light-year]]s from the Solar System in the [[Draco (constellation)|Draco constellation]]. It is approximately the same size as the [[Sun]], with an estimated age of 12&nbsp;billion years.<ref name="kepler10bData" /> Planet Kepler-10b was the first planet to be discovered in the orbit of its star. For this, it was designated the star's ''b'' planet. The star, in turn, was named for the Kepler Mission, a NASA-led operation aimed at discovering terrestrial planets that [[transit method|transit]], or cross in front of, their host stars with respect to Earth.<ref name="Mission overview"/> The planet's discovery was announced to the public on January 10, 2011.<ref name="Dennis Overbye">{{cite news | url=https://www.nytimes.com/2011/01/11/science/space/11planet.html |title=Kepler-10b, a Lethally Hot Exoplanet, Is Discovered | author=Dennis Overbye | date=10 January 2011 | newspaper=[[New York Times]] | access-date=6 March 2011}}</ref>
[[File:Lightcurve20090111Kepler-10b.jpg|thumb|left|170px|The [[light curve]] for Kepler-10b, demonstrating the dimming effect as it [[transit method|transits]] its star]]
The transit method of discovering [[Extrasolar planet|exoplanet]]s relies upon carefully monitoring the brightness of a star. If a planet is present and crosses the line of sight between Earth and the star, the star will dim at a regular interval by an amount that depends upon the radius of the transiting planet. In order to measure the mass of a planet, and rule out other phenomena that can mimic the presence of a planet transiting a star, candidate transiting planets are followed up with the [[radial velocity method]] of detecting extrasolar planets.<ref name="Seager2003" />

Kepler-10b's discovery was based on eight months of data collected with the Kepler telescope from May 2009 to January 2010. The planet's first transits were observed in July 2009. According to the collected data, Kepler-10 dimmed by one part in ten thousand every 0.83 days.<ref name="NASANews"/><ref name="WiredScience" /> Kepler-10 was the first star in the [[field of view]] of the Kepler telescope identified as capable of harboring a small transiting planet, and was considered a high priority target for ground-based radial velocity observations intended to confirm the mass of Kepler-10b. Radial velocity measurements with the [[Keck I]] telescope taken intermittently between August 2009 and August 2010 revealed a periodic [[Doppler shift]] in the spectrum of Kepler-10 consistent with a planet of the nature observed by Kepler, confirming the planet's existence and allowing its mass to be determined.<ref name="Batalha2011"/><ref name="NASANews"/> The planet's discovery was announced to the public on January 10, 2011.<ref name="Dennis Overbye"/>

In September 2011, the detection of secondary transit and phases were announced. This allowed to determine the temperature and albedo of the planet. This is the first terrestrial exoplanet with observed phases. Detection of phases was possible due to extreme day/night side temperature variations and the amount of starlight the planet receives due to its proximity to the host star.<ref>[https://arxiv.org/abs/1109.2768  The orbital phases and secondary transit of Kepler-10b - A physical interpretation based on the Lava-ocean planet model] : Daniel Rouan, Hans J. Deeg, Olivier Demangeon, Benjamin Samuel, Céline Cavarroc, Bruce Fegley, Alain Léger</ref>

===Reaction===
Kepler-10b's discovery excited astronomers, who hoped to use data about it to inquire into the formation and structure that terrestrial, Earth-size planets tend to have in common.<ref>{{cite news |url=http://content.usatoday.com/communities/sciencefair/post/2011/01/rocky-exoplanet-reaction-round-up/1 |title=Kepler's rocky exoplanet reaction round-up |author=Dan Vergano |date=10 January 2011 |work=Science Fair |publisher=[[USA Today]] |access-date=11 March 2011}}</ref> Diana Valencia at the University of Côte d'Azur in Nice, France considered the planet more of a "super-Mercury" than a super-Earth, granted its physical characteristics.<ref>{{cite web |url=http://www.sciencenews.org/view/generic/id/68586/title/New_planet_small_but_tough |title=New Planet Small But Tough |author=Ron Cowen |date=12 February 2011 |publisher=ScienceNews |access-date=11 March 2011}}</ref>

==Characteristics==
[[File:CompositionOfKepler-10b.jpg|left|thumb|330px|Diagram showing composition of Kepler-10b in comparison with other planets and exoplanets]]
Kepler-10b is most noted for its rocky surface. It has a diameter 1.47&nbsp;times that of the [[Earth]]. The mass of Kepler-10b is 3.58 times that of Earth<ref name=Brinkman/> and the average density is {{val|6.46}} [[g/cm3|g/cm<sup>3</sup>]].<ref name="Weiss2016"/> It orbits its star, [[Kepler-10]], in less than a day, at less than a twentieth of the distance from [[Mercury (planet)|Mercury]] to the [[Sun]]. Its surface temperature on the star lit side is approximately 1,833&nbsp;[[Kelvin|K]],<ref name="Kepler-10b">{{cite web|date=2011-01-10|title=Kepler Discoveries: Kepler-10b|publisher=Kepler @ NASA|url=http://kepler.nasa.gov/Mission/discoveries/kepler10b/|archive-url=https://web.archive.org/web/20110721122709/http://kepler.nasa.gov/Mission/discoveries/kepler10b/|url-status=dead|archive-date=2011-07-21|access-date=2011-01-12}}</ref> which is as hot as a [[blast furnace]] and hot enough to melt iron.<ref name="WiredScience" />

Though [[CoRoT-7b]] was discovered before Kepler-10b and has been claimed to be rocky, there is more room for other interpretations in the case of CoRoT-7b's composition than there is for Kepler-10b, due to its highly uncertain mass — for example, it could be predominantly water rather than rock and iron.<ref name="WiredScience" />

Kepler-10b is tidally locked to its parent star and has extreme variations in temperature between day and night sides. It also reflects about half of the starlight it receives. One possible explanation for the high Bond albedo could be that Kepler-10b is a [[Coreless planet|coreless rocky planet]] with surface magma oceans rich in iron oxides.<ref>Modirrousta-Galian, D., Ito, Y. and Micela, G., (2020). Exploring super-Earth surfaces: Albedo of near-airless magma ocean planets and topography. Icarus, p.114175.</ref>

==See also==
* [[Kepler-10c]]
* [[Kepler Mission]]
* [[Kepler-4b]], [[Kepler-5b|5b]], [[Kepler-6b|6b]], [[Kepler-7b|7b]], [[Kepler-8b|8b]], [[Kepler-9b|9b]], [[Kepler-78b|78b]]
* [[List of exoplanet extremes]]

==References==
{{reflist|refs=

<ref name="BBCNews">
{{cite news |url=https://www.bbc.co.uk/news/science-environment-12158028 |title= BBC News|date=2010-01-10 |publisher=BBC|access-date=2010-11-01}}</ref>

<ref name="Batalha2011">{{cite journal | title=Kepler's First Rocky Planet: Kepler-10b | last1=Batalha | first1=Natalie M. | last2=Borucki | first2=William J. | last3=Bryson | first3=Stephen T. | last4=Buchhave | first4=Lars A. | last5=Caldwell | first5=Douglas A. | last6=Christensen-Dalsgaard | first6=Jørgen | last7=Ciardi | first7=David | last8=Dunham | first8=Edward W. | last9=Fressin | first9=Francois | last10=Gautier | first10=Thomas N. | last11=Gilliland | first11=Ronald L. | last12=Haas | first12=Michael R. | last13=Howell | first13=Steve B. | last14=Jenkins | first14=Jon M. | last15=Kjeldsen | first15=Hans | last16=Koch | first16=David G. | last17=Latham | first17=David W. | last18=Lissauer | first18=Jack J. | last19=Marcy | first19=Geoffrey W. | last20=Rowe | first20=Jason F. | last21=Sasselov | first21=Dimitar D. | last22=Seager | first22=Sara | last23=Steffen | first23=Jason H. | last24=Torres | first24=Guillermo | last25=Basri | first25=Gibor S. | last26=Brown | first26=Timothy M. | last27=Charbonneau | first27=David | last28=Christiansen | first28=Jessie | last29=Clarke | first29=Bruce | last30=Cochran | first30=William D. | display-authors=1 | journal=The Astrophysical Journal | volume=729 | issue=1 | pages=27 | year=2011 | arxiv=1102.0605 | bibcode=2011ApJ...729...27B | doi=10.1088/0004-637X/729/1/27 | s2cid=55059000 }}</ref>

<ref name="datatable">
{{cite web |url=http://kepler.nasa.gov/Mission/discoveries/  |archive-url=https://web.archive.org/web/20100527104316/http://kepler.nasa.gov/Mission/discoveries/  |url-status=dead  |archive-date=2010-05-27  |title=Summary Table of Kepler Discoveries |date=2010-08-26 |publisher=NASA|access-date=2010-09-01}}</ref>

<ref name="harps">{{Cite journal |last=Dumusque |first=Xavier |last2=Bonomo |first2=Aldo S. |last3=Haywood |first3=Raphaelle D. |last4=Malavolta |first4=Luca |last5=Segransan |first5=Damien |last6=Buchhave |first6=Lars A. |last7=Cameron |first7=Andrew Collier |last8=Latham |first8=David W. |last9=Molinari |first9=Emilio |last10=Pepe |first10=Francesco |last11=Udry |first11=Stephane |last12=Charbonneau |first12=David |last13=Cosentino |first13=Rosario |last14=Dressing |first14=Courtney D. |last15=Figueira |first15=Pedro |date=2014-06-24 |title=The Kepler-10 planetary system revisited by HARPS-N: A hot rocky world and a solid Neptune-mass planet |url=https://arxiv.org/abs/1405.7881 |journal=The Astrophysical Journal |volume=789 |issue=2 |pages=154 |doi=10.1088/0004-637X/789/2/154 |issn=0004-637X}}</ref>

<ref name="kepler10bData">
{{cite web | url = http://kepler.nasa.gov/Mission/discoveries/kepler10b/ | archive-url = https://web.archive.org/web/20110721122709/http://kepler.nasa.gov/Mission/discoveries/kepler10b/ | url-status = dead | archive-date = 2011-07-21 | title = Kepler-10b | date = 2011-01-10 | publisher = NASA | access-date = 2010-01-15}}</ref>

<ref name="Mission overview">{{cite web | title=Mission overview | url=https://www.nasa.gov/mission_pages/kepler/overview/index.html | work=Kepler and K2 | date=13 April 2015 | publisher=NASA | access-date=3 December 2017}}</ref>

<ref name="NASANews">{{cite web |url=http://www.nasa.gov/topics/universe/features/rocky_planet.html |title=NASA'S Kepler Mission Discovers Its First Rocky Planet |date=2011-01-10 |publisher=NASA |access-date=2011-01-10 |archive-date=2015-06-27 |archive-url=https://web.archive.org/web/20150627200219/http://www.nasa.gov/topics/universe/features/rocky_planet.html |url-status=dead }}</ref>

<ref name="Seager2003">{{Cite journal | last1 = Seager  | first1 = S. | last2 = Mallen‐ornelas | first2 = G. | date = 2003 | title = A Unique Solution of Planet and Star Parameters from an Extrasolar Planet Transit Light Curve | journal = [[The Astrophysical Journal]] | volume = 585 | issue = 2 | pages = 1038–1055 | arxiv = astro-ph/0206228 | bibcode=2003ApJ...585.1038S | doi = 10.1086/346105| s2cid = 14274640 }}</ref>

<ref name="WiredScience">
{{cite magazine | url = https://www.wired.com/wiredscience/2011/01/kepler-rocky-world/ | title = Kepler Finds First Definitively Rocky Exoplanet | author = Grossman, Lisa | date = 2010-01-10 | magazine = Wired | access-date = 2011-01-15 | archive-url = https://web.archive.org/web/20140602142730/http://www.wired.com/2011/01/kepler-rocky-world/ | archive-date = 2014-06-02 }}</ref>

<ref name = "Weiss2016">[http://iopscience.iop.org/article/10.3847/0004-637X/819/1/83/pdf],
Weiss L. M., et al., 2016, Astrophys. J., 819, 83</ref>
}}

==External links==
* {{Commons category-inline|Kepler-10 b}}
* [https://web.archive.org/web/20110721122709/http://kepler.nasa.gov/Mission/discoveries/kepler10b/ NASA Kepler Mission (Kepler Discoveries): Kepler-10b]
* [https://www.youtube.com/watch?v=S5ZJEiGOHTo YouTube: Narrated Animation on Kepler-10b]

{{Kepler-10}}
{{2011 in space}}
{{Stars of Draco}}

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{{s-bef|before=[[Earth]]}}
{{s-ttl|title=Most dense planet|years=2011}}
{{s-aft|after=[[PSR J1719-1438 b]]}}
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{{s-ttl|title=[[List of extrasolar planet extremes|Most dense exoplanet]]|years=2011}}
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{{Sky|19|2|43|+|50|14|29|564}}

{{DEFAULTSORT:Kepler-10b}}
[[Category:Exoplanets with Kepler designations]]
[[Category:Exoplanets discovered in 2011]]
[[Category:Kepler-10|B]]
[[Category:Super-Earths]]
[[Category:Terrestrial planets]]
[[Category:Transiting exoplanets]]
[[Category:Draco (constellation)]]
[[Category:Exoplanets discovered by the Kepler space telescope|10b]]