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{{Planetbox begin | |||
| name= Kepler-4b | |||
}} | |||
{{Planetbox image | |||
| image = Exoplanet Comparison Kepler-4 b.png | |||
| caption = Size comparison of Kepler-4b (right) with [[Neptune]] (left). | |||
}} | |||
{{Planetbox star | |||
| star = [[Kepler-4]]<ref name=datatable /> | |||
| constell= [[Draco (constellation)|Draco]] | |||
| RA = {{RA|19|2|27.7}} | |||
| DEC= {{DEC|+50|8|8.7}} | |||
| app_mag = 12.6<ref name=datatable /> | |||
| dist_pc = 550<ref name=datatable /> | |||
| dist_ly = 1631 | |||
| mass = 1.223<ref name=datatable /> | |||
| radius = 1.487<ref name=datatable /> | |||
| temperature = 5857<ref name=datatable /> | |||
| luminosity = 0.354 ± 0.1 | |||
| metallicity = 0.17<ref name=datatable /> | |||
| age = 4.5<ref name="EPE"/> | |||
}} | |||
{{Planetbox character | |||
| radius_earth = 3.878 | |||
| radius = 0.357<ref name=datatable /> | |||
| mass = .077<ref name=datatable /> | |||
| temperature = 1650<ref name=datatable /> | |||
| stellar_flux = ~168 | |||
}} | |||
{{Planetbox orbit | |||
| period = 3.2135<ref name=datatable /> | |||
| semimajor = .04558<ref name=datatable /> | |||
| eccentricity = 0.25 ± 0.12<ref name="Kipping2010"/> | |||
| inclination = 89.76<ref name=datatable /> | |||
}} | |||
{{Planetbox discovery | |||
| discovery_date = 2010-01-04<ref name=Talcott /> | |||
| discoverers = | |||
| discovery_method = [[Methods of detecting extrasolar planets#Transit method|Transit]] ([[Kepler Mission]])<ref name=QuickGuide /> | |||
| detection_methods = Radial velocity | |||
| discovery_status = Conference announcement<ref name=Talcott /> | |||
}} | |||
{{Planetbox end}} | |||
'''Kepler-4b''', initially known as '''KOI 7.01''', is an [[exoplanet|extrasolar planet]] first detected as a [[astronomical transit|transit]] by the [[Kepler (spacecraft)|Kepler spacecraft]]. Its [[radius]] and [[mass]] are similar to that of [[Neptune]]; however, due to its proximity to its host star, it is substantially hotter than any planet in the Solar System.<ref name="datatable"/><ref name="sciencenews"/> The planet's discovery was announced on January 4, 2010 in [[Washington, D.C.]] along with four other planets that were initially detected by the Kepler spacecraft and subsequently confirmed by telescopes at the [[W.M. Keck Observatory]]. | |||
==Nomenclature and history== | |||
Kepler-4b was named because it was the first planet discovered in the orbit of its star, [[Kepler-4]]. The star was, in turn, named for the Kepler Mission, a [[NASA]] satellite whose purpose is to discover Earth-like planets in a section of the sky between constellations [[Cygnus (constellation)|Cygnus]] and [[Lyra]] using the transit method. Using this method, Kepler notes small and steady decreases in a star's brightness that are measured as a planet crosses in front of it.<ref name=QuickGuide>{{cite web |url=http://kepler.nasa.gov/Mission/QuickGuide/ |title=Kepler: About the Mission |author= |year=2011 |work=Kepler Mission |publisher=NASA |accessdate=11 March 2011}}</ref> Initially, Kepler-4b was detected as a transit event by the [[Kepler telescope]] and considered a [[Kepler Object of Interest]] with the designation KOI 7.01.<ref name="Borucki2011"/> | |||
Subsequent [[radial velocity]] measurements by the [[High Resolution Echelle Spectrometer]] on the telescopes of W.M. Keck Observatory confirmed the planetary nature of the transit event and established a mass estimate for the planet.<ref name="Borucki2010"/> The planet's existence was announced on January 4, 2010 along with four other planets detected by Kepler: [[Kepler-5b]], [[Kepler-6b|6b]], [[Kepler-7b|7b]] and [[Kepler-8b|8b]]<ref name="sciencenews"/> at the [[American Astronomical Society 215th meeting|215th]] meeting of the [[American Astronomical Society]] in Washington, D.C.<ref name=Talcott>{{cite web |url=http://cs.astronomy.com/asycs/blogs/astronomy/archive/2010/01/05/215th-aas-meeting-update-kepler-discoveries-the-talk-of-the-town.aspx |title=215th AAS meeting update: Kepler discoveries the talk of the town |author=Rich Talcott |date=5 January 2010 |work=Astronomy.com |publisher=''[[Astronomy (magazine)|Astronomy]]'' magazine |accessdate=11 March 2011}}</ref> | |||
==Host star== | |||
{{main|Kepler-4}} | |||
Kepler-4 is located within the [[Draco (constellation)|Draco constellation]] on the sky, and is approximately 550 [[parsecs]] from our solar system. It has an effective temperature almost identical to the [[Sun]] at 5857 [[Kelvin]], but a mass and radius that are somewhat larger than the sun: respectively, 1.223 [[solar mass|<math>\begin{smallmatrix}M_\odot\end{smallmatrix}</math>]] and 1.487 [[solar radius|<math>\begin{smallmatrix}R_\odot\end{smallmatrix}</math>]]. The star is thought to be around 4.5 billion years old, and at or very near the end of its [[main-sequence]] [[hydrogen burning]] phase. In several tens of millions of years it will likely become a [[subgiant]] star.<ref name="Borucki2010"/> | |||
==Characteristics== | |||
Kepler-4b orbits its host star in 3.213 days at a distance of 0.046 [[astronomical unit|AU]].<ref name="Borucki2010"/> This places it almost 10 times closer to its star than Mercury is to the Sun. Consequently, Kepler-4b is thought to be extremely hot, with an [[equilibrium temperature]] greater than 1700 [[Kelvin]] (2600 Fahrenheit).<ref name="Kipping2010"/> The planet is estimated to be 25 times more massive than the Earth with a radius that is 4 times greater than the Earth.<ref name="Borucki2010"/> This makes it similar to Neptune in terms of size and mass, but with a temperature that is not comparable to any planet in our solar system (Venus, the hottest planet is only 735 Kelvin). Kepler-4b's [[orbital eccentricity|eccentricity]] was assumed to be 0, however an independent reanalysis of the discovery data found a value of 0.25 ± 0.12.<ref name="Kipping2010"/> | |||
[[File:Kepler first five exoplanet size.jpg|thumb|300px|A picture showing the relative sizes of the first five planets discovered by Kepler. Kepler-4b is the smallest of the five, highlighted in purple.]] | |||
== See also == | |||
* [[Kepler-5b]] | |||
* [[Kepler-6b]] | |||
* [[Kepler-7b]] | |||
* [[Kepler-8b]] | |||
* [[Kepler-9b]] | |||
* [[Kepler-10b]] | |||
== References == | |||
{{reflist|refs= | |||
<ref name="Borucki2010">{{cite journal | title=Kepler-4b: A Hot Neptune-like Planet of a G0 Star Near Main-sequence Turnoff | url=http://iopscience.iop.org/2041-8205/713/2/L126/fulltext/ | last1=Borucki | first1=William J. | last2=Koch | first2=David G. | last3=Brown | first3=Timothy M. | last4=Basri | first4=Gibor | last5=Batalha | first5=Natalie M. | last6=Caldwell | first6=Douglas A. | last7=Cochran | first7=William D. | last8=Dunham | first8=Edward W. | last9=Gautier III | first9=Thomas N. | display-authors=1 | journal=The Astrophysical Journal Letters | year=2010 | volume=713 | issue=2 | page=L126 | arxiv=1001.0604 | bibcode=2010ApJ...713L.126B | doi=10.1088/2041-8205/713/2/L126 }}</ref> | |||
.<ref name ="Borucki2011">{{cite web| author=Borucki, William J; et al. | title=Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data | url=http://kepler.nasa.gov/files/mws/FebDataRelease_revised_020211.pdf |publisher=http://kepler.nasa.gov | date=2011-02-01 |accessdate=2011-03-07}}</ref> | |||
<ref name="EPE">{{cite web | url=http://exoplanet.eu/catalog/kepler-4_b/ | title=Planet Kepler-4 b | |||
| author=Jean Schneider | year=2010 | work=[[Extrasolar Planets Encyclopaedia]] | publisher=Jean Schneider | accessdate=5 August 2012}}</ref> | |||
<ref name="Kipping2010">{{cite journal | title=An Independent Analysis of Kepler-4b through Kepler-8b | url=http://iopscience.iop.org/0004-637X/730/1/50/fulltext/ | last1=Kipping | first1=David | last2=Bakos | first2=Gáspár | journal=The Astrophysical Journal | year=2011 | volume=730 | issue=1 | at=50 | arxiv=1004.3538 | bibcode=2011ApJ...730...50K | doi=10.1088/0004-637X/730/1/50 }}</ref> | |||
<ref name="sciencenews"> | |||
{{cite web |url=http://www.usnews.com/science/articles/2010/01/04/space-telescope-finds-its-first-extrasolar-planets |title=Kepler space telescope finds its first extrasolar planets |author=Ron Cowen |date=2010-01-04 |work= |publisher=Science News|accessdate=2010-01-04}}</ref> | |||
<ref name="datatable"> | |||
{{cite web |url=http://kepler.nasa.gov/Mission/discoveries/ |title=Summary Table of Kepler Discoveries |date=2010-03-15 |work= |publisher=NASA|accessdate=2010-03-18}}</ref> | |||
}} | |||
== External links == | |||
{{commonscat-inline|Kepler-4 b}} | |||
*http://kepler.nasa.gov/Mission/discoveries/kepler4b/ | |||
{{Sky|19|2|27.7|+|50|8|8.7| 550}} | |||
[[Category:Exoplanets discovered in 2010]] | |||
[[Category:Hot Neptunes]] | |||
[[Category:Gas giants]] | |||
[[Category:Transiting exoplanets]] | |||
[[Category:Draco (constellation)]] | |||
[[Category:Exoplanets discovered by Kepler (spacecraft)|4b]] |
Revision as of 03:50, 20 January 2013
Template:Good article Template:Planetbox begin Template:Planetbox image Template:Planetbox star Template:Planetbox character Template:Planetbox orbit Template:Planetbox discovery Template:Planetbox end
Kepler-4b, initially known as KOI 7.01, is an extrasolar planet first detected as a transit by the Kepler spacecraft. Its radius and mass are similar to that of Neptune; however, due to its proximity to its host star, it is substantially hotter than any planet in the Solar System.[1][2] The planet's discovery was announced on January 4, 2010 in Washington, D.C. along with four other planets that were initially detected by the Kepler spacecraft and subsequently confirmed by telescopes at the W.M. Keck Observatory.
Nomenclature and history
Kepler-4b was named because it was the first planet discovered in the orbit of its star, Kepler-4. The star was, in turn, named for the Kepler Mission, a NASA satellite whose purpose is to discover Earth-like planets in a section of the sky between constellations Cygnus and Lyra using the transit method. Using this method, Kepler notes small and steady decreases in a star's brightness that are measured as a planet crosses in front of it.[3] Initially, Kepler-4b was detected as a transit event by the Kepler telescope and considered a Kepler Object of Interest with the designation KOI 7.01.[4]
Subsequent radial velocity measurements by the High Resolution Echelle Spectrometer on the telescopes of W.M. Keck Observatory confirmed the planetary nature of the transit event and established a mass estimate for the planet.[5] The planet's existence was announced on January 4, 2010 along with four other planets detected by Kepler: Kepler-5b, 6b, 7b and 8b[2] at the 215th meeting of the American Astronomical Society in Washington, D.C.[6]
Host star
Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. Kepler-4 is located within the Draco constellation on the sky, and is approximately 550 parsecs from our solar system. It has an effective temperature almost identical to the Sun at 5857 Kelvin, but a mass and radius that are somewhat larger than the sun: respectively, 1.223 and 1.487 . The star is thought to be around 4.5 billion years old, and at or very near the end of its main-sequence hydrogen burning phase. In several tens of millions of years it will likely become a subgiant star.[5]
Characteristics
Kepler-4b orbits its host star in 3.213 days at a distance of 0.046 AU.[5] This places it almost 10 times closer to its star than Mercury is to the Sun. Consequently, Kepler-4b is thought to be extremely hot, with an equilibrium temperature greater than 1700 Kelvin (2600 Fahrenheit).[7] The planet is estimated to be 25 times more massive than the Earth with a radius that is 4 times greater than the Earth.[5] This makes it similar to Neptune in terms of size and mass, but with a temperature that is not comparable to any planet in our solar system (Venus, the hottest planet is only 735 Kelvin). Kepler-4b's eccentricity was assumed to be 0, however an independent reanalysis of the discovery data found a value of 0.25 ± 0.12.[7]
See also
References
43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.
External links
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