Astronomy:Kepler-56b
 A diagram of the planetary system of Kepler-56 | |
| Discovery | |
|---|---|
| Discovered by | Daniel Huber et al.[1] |
| Discovery date | 16 October 2013 |
| Transit method | |
| Orbital characteristics | |
| 0.1028 ± 0.0037 AU (15,380,000 ± 550,000 km)[1] | |
| Orbital period | 10.5016+0.0011 −0.0010[1] d |
| Star | Kepler-56 |
| Physical characteristics | |
| Mean radius | 6.51+0.29 −0.28[1] R⊕ |
| Mass | 22.1+3.9 −3.6[1] M⊕ |
| Mean density | 0.442+0.080 −0.072 g cm−3 |
Kepler-56b (KOI-1241.02)[2] is a hot Neptune[1]—a class of exoplanets—located roughly 3,060 light-years (940 parsecs) away. It is somewhat larger than Neptune[3] and orbits its parent star Kepler-56 and was discovered in 2013 by the Kepler Space Telescope.
Planetary orbit
Kepler-56b is about 0.1028 astronomical unit|AU (9.56 million mi; 15.38 million km) away from its host star[1] (about one-tenth of the distance between Earth to the Sun), making it even closer to its parent star than Mercury (0.39 AU [36 million mi; 58 million km]) and Venus (0.72 AU [67 million mi; 110 million km]). It takes 10.5 days for Kepler-56b to complete a full orbit around its star.[1] Further research shows that Kepler-56b's orbit is about 45° misaligned to the host star's equator. Later radial velocity measurements have revealed evidence of a gravitational perturbation from Kepler-56d.
Both Kepler-56b and Kepler-56c will be devoured by their parent star in about 130 and 155 million years.[4] Even further research shows that it will have its atmosphere boiled away by intense heat from the star, and it will be stretched by the strengthening stellar tides.[4] The measured mass of Kepler-56b is about 30% larger than Neptune's mass, but its radius is roughly 70% larger than Neptune's. Therefore, Kepler-56b should have a hydrogen/helium envelope containing a significant fraction of its total mass.[5][6] Like Kepler-11b and Kepler-11c, the envelope's light elements are susceptible to photo-evaporation caused by radiation from the central star. For example, it has been calculated that Kepler-11c lost over 50% of its hydrogen/helium envelope after formation.[7] However, the larger mass of Kepler-56b, compared to that of Kepler-11c, reduces the efficiency of mass loss.[7] Nonetheless, the planet may have been significantly more massive in the past and may keep losing mass in the future.
Other planets in the Kepler-56 system
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Huber, D. et al. (2013). "Stellar Spin-Orbit Misalignment in a Multiplanet System". Science 342 (6156): 331–334. doi:10.1126/science.1242066. PMID 24136961. Bibcode: 2013Sci...342..331H.
- ↑ "KOI-1241.02". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=KOI-1241.02.
- ↑ "NASA Exoplanet Archive". Operated by the California Institute of Technology, under contract with NASA. https://exoplanetarchive.ipac.caltech.edu/index.html.
- ↑ 4.0 4.1 Charles Poladian (2014-06-03). "Cosmic Snack: Planets Kepler-56b And Kepler-56c Will Be Swallowed Whole By Host Star". International Business Times. http://www.ibtimes.com/cosmic-snack-planets-kepler-56b-kepler-56c-will-be-swallowed-whole-host-star-1593918. Retrieved 2017-09-07.
- ↑ Lissauer, J. J.; Hubickyj, O.; D'Angelo, G.; Bodenheimer, P. (2009). "Models of Jupiter's growth incorporating thermal and hydrodynamic constraints". Icarus 199 (2): 338–350. doi:10.1016/j.icarus.2008.10.004. Bibcode: 2009Icar..199..338L.
- ↑ D'Angelo, G.; Weidenschilling, S. J.; Lissauer, J. J.; Bodenheimer, P. (2014). "Growth of Jupiter: Enhancement of core accretion by a voluminous low-mass envelope". Icarus 241: 298–312. doi:10.1016/j.icarus.2014.06.029. Bibcode: 2014Icar..241..298D.
- ↑ 7.0 7.1 D'Angelo, G.; Bodenheimer, P. (2016). "In Situ and Ex Situ Formation Models of Kepler 11 Planets". The Astrophysical Journal 828 (1): id. 33. doi:10.3847/0004-637X/828/1/33. Bibcode: 2016ApJ...828...33D.
Further reading
- Steffen, Jason H et al. (20 August 2012). "Transit Timing Observations from Kepler: VII. Confirmation of 27 planets in 13 multiplanet systems via Transit Timing Variations and orbital stability". Mon. Not. R. Astron. Soc. 428 (2): 1077. doi:10.1093/mnras/sts090. Bibcode: 2013MNRAS.428.1077S.
External links
- "Kepler-56b". kepler.nasa.gov. http://kepler.nasa.gov/Mission/discoveries/kepler56b/. Retrieved 2016-01-02.
- Megan Smith (8 June 2014). "Star to Swallow not One, but Two Exoplanets". Futurism LLC. http://futurism.com/star-swallows-not-one-but-two-exoplanets-2014/.
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