Kepler-69c

Kepler-69c[1][2][3]
Exoplanet List of exoplanets
Parent star
Star Kepler-69 (KIC=8692861)[4][5][6][7][8][9][10] [11]
Constellation Cygnus[12]
Right ascension (α) 19h 33m 02.622s[4]
Declination (δ) +44° 52′ 08.00″[4]
Apparent magnitude (mV) 13.7[1]
Distance2700;[13] 1040.0[10] ly
(830 pc)
Spectral type G4V[8]
Mass (m) 0.98;[10] null[5] M☉
Radius (r) 0.900;[4] 0.655; 0.69[5] R☉
Temperature (T) 5603;[5] 5886[4] K
Metallicity [Fe/H] −0.540; null[5]
Age 0.400[4] Gyr
Physical characteristics
Radius(r)1.71+0.34
−0.23[1] R⊕
Stellar flux(F⊙)1.91 (+0.43
−0.56)[14] ⊕
Temperature (T) 281;[4] 299[1]
Orbital elements
Semi-major axis(a) 0.64+0.15
−0.11[4][5] AU
Eccentricity (e) 0.14+0.18
−0.1[4][5]
Orbital period(P) 242.4613+0.0059
−0.0064[1][4][5] d
Inclination (i) 89.85+0.03
−0.08[4][5]°
Time of transit (Tt) 150.867[4][5] JD
Discovery information
Discovery date 17 April 2013
Discoverer(s) Barclay et al.
Discovery method Transit (Kepler Mission Method)
Discovery site Kepler Space Observatory
Discovery status Conference announcement
Other designations
KOI-172.02
Database references
Extrasolar Planets
Encyclopaedia		data
SIMBADdata
Exoplanet Archivedata
Open Exoplanet Cataloguedata

Kepler-69c[1][2][3] (also known by its Kepler Object of Interest designation KOI-172.02)[5][10] is a confirmed super-Earth extrasolar planet, about 70% larger than Earth, orbiting a Sun-like G-type star, Kepler-69, located about 2,700 ly (830 pc) from Earth in the constellation of Cygnus. The planet was discovered by NASA's Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Kepler-69c is most likely a terrestrial planet. Initial discovery of the planet was announced on January 7, 2013;[7][8] confirmation was announced on April 18, 2013. Although it was initially thought to be in the habitable zone,[15] it is now thought to represent a super-Venus, analogous to Venus but more massive, and thus highly unlikely to be habitable for life as we know it.[11]

Confirmed exoplanet

Kepler-69c, a super-Earth, has a radius 1.7 times that of Earth. The planet orbits a Sun-like star, named Kepler-69, once every 242.5 days.[5]

Habitability

The planet was announced in the media as being located within the star's "habitable zone", a region where liquid water could exist on the surface of the planet. It was described as being one of the most Earth-like planets, in terms of size and temperature yet found and, according to the scientists, a "prime candidate to host alien life".[8] Due to uncertainties in the stellar parameters, the error bars on the value of the incident flux on this planet are quite large, at 1.91+0.43
−0.56 times the level of Earth. Using the nominal parameters, the planet is too close to the star to be habitable, though the uncertainties allow for the possibility that it may actually lie in the innermost region of the habitable zone.[16] A more recent analysis has shown that the planet is likely more analogous to Venus, which is known to be one of the most inhospitable places to life as we know it in the Solar System, and thus unlikely to be habitable to such organisms.[11]

Host star and star system

The host star, Kepler-69 (KIC 8692861, 2MASS J19330262+4452080),[5] is a G-type main-sequence star somewhat cooler than the Sun.[8] On April 18, 2013, it was announced that two planets orbit Kepler-69: an inner planet, Kepler-69b, and an outer planet, Kepler-69c.[1][2][3] Kepler-69c is about 70 million miles from its host star (compared to 93 million miles between Earth and the Sun) and takes 242 days to orbit its star (compared to the 365 days of Earth).[8]

Kepler-69 Comparisons
Star systems – Kepler-69 System and the Solar System
Planet sizes – Kepler-69c, Kepler-62e, Kepler-62f, and Earth

See also

References

  1. 1 2 3 4 5 6 7 Barclay, Thomas; et al. (17 April 2013). "A super-Earth-sized planet orbiting in or near the habitable zone around Sun-like star". arXiv. arXiv:1304.4941v1. Retrieved 18 April 2013.
  2. 1 2 3 Johnson, Michele; Harrington, J.D. (18 April 2013). "NASA's Kepler Discovers Its Smallest 'Habitable Zone' Planets to Date". NASA. Retrieved 18 April 2013.
  3. 1 2 3 Overbye, Dennis (18 April 2013). "2 Good Places to Live, 1,200 Light-Years Away". New York Times. Retrieved 18 April 2013.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 Staff (January 7, 2013). "Kepler KOI Search Results for KOI-172.02". Space Telescope Science Institute. Retrieved January 11, 2013.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 Staff. "NASA Exoplanet Archive -KOI-172.02". Caltech. Retrieved January 11, 2013.
  6. ↑ Graham, Keith P. (2008). "Star Finder for KIC=8692861". CThreePO.com. Retrieved January 11, 2013.
  7. 1 2 Harrington, J. D.; Johnson, Michele (January 7, 2013). "NASA'S Kepler Mission Discovers 461 New Planet Candidates". NASA. Retrieved January 11, 2013.
  8. 1 2 3 4 5 6 Moskowitz, Clara (January 9, 2013). "Most Earth-Like Alien Planet Possibly Found". Space.com. Retrieved January 9, 2013.
  9. ↑ Borucki, William J.; et al. (July 20, 2011). "Characteristics of planetary candidates observed by Kepler, II: Analysis of the first four months of data". The Astrophysical Journal 736: 19. arXiv:1102.0541. Bibcode:2011ApJ...736...19B. doi:10.1088/0004-637X/736/1/19. Retrieved January 12, 2013.
  10. 1 2 3 4 Johnston, Wm. Robert (October 2, 2011). "List of Extrasolar Planets". JohnstonArchive.com. Retrieved January 11, 2013.
  11. 1 2 3 Kane, Stephen; et al. "A Potential Super-Venus in the Kepler-69 System". arXiv.
  12. ↑ Walker, John (April 4, 2003). "Your Sky - The Virtual Telescope". fourmilab.ch. Retrieved January 13, 2013.
  13. ↑ Batalha, Natalie (January 17, 2013). "Astronomer, Kepler Space Observatory - Message Post". Facebook. Retrieved January 17, 2013.
  14. ↑ Kaltenegger, L. "Water-Planets in the Habitable Zone: Atmospheric Chemistry, Observable Features, and the case of Kepler-62e and -62f". arXiv:1304.5058.
  15. ↑ 3 Potentially Habitable 'Super-Earths' Explained (Infographic)
  16. ↑ L. Kaltenegger, D. Sasselov, S. Rugheimer (2013). "Water Planets in the Habitable Zone: Atmospheric Chemistry, Observable Features, and the case of Kepler-62e and -62f". arXiv:1304.5058v1 [astro-ph.EP].

External links

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Coordinates: 19h 33m 02.622s, +44° 52′ 08.00″

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