Astronomy:Kepler-36
Kepler-36 is a star in the constellation of Cygnus with two known planets. It has an anomalously large radius, meaning that it is a subgiant.
Planetary system
On June 21, 2012, the discovery of two planets orbiting the star was announced. The planets, a super-Earth and a mini-Neptune, are unusual in that they have very close orbits; their semi-major axes differ by only 0.013 AU. The outer planet orbits only 11% farther than the inner one. Coupled with masses significantly higher than Earth, their gravitational influence to each other is significant, meaning that their interaction causes extreme transit timing variations for both. Kepler-36b and c have estimated densities of 6.8 and 0.86 g/cm3, respectively.[1] The two planets are close to a 7:6 orbital resonance.[1] Kepler-36 is the most compact known resonant system with the 7:6 mean-motion resonance marking the last attainable stable period ratio.[2]
The large difference in densities, despite the close proximity of the planets' orbits, is likely due to the large difference in mass.[3] The innermost and less massive planet likely lost most, or all, of the hydrogen/helium envelope acquired during formation.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 3.83+0.11 −0.10 M⊕ |
0.1153 | 13.86821±0.00049 | <0.04 | 90.0° | 1.498+0.061 −0.049 R⊕ |
| c | 7.13±0.18 M⊕ | 0.1283 | 16.21865±0.00010 | <0.04 | 90.0° | 3.679+0.096 −0.091 R⊕ |
References
- ↑ 1.0 1.1 1.2 Carter, J. A. et al. (2012). "Kepler-36: A Pair of Planets with Neighboring Orbits and Dissimilar Densities". Science 337 (6094): 556–559. doi:10.1126/science.1223269. PMID 22722249. Bibcode: 2012Sci...337..556C.
- ↑ Batygin, Konstantin; Morbidelli, Alessandro (2026-05-01). "Origins of Compact Mean-motion Resonances: Evidence for Long-range Migration and the Case of Kepler-36". The Astrophysical Journal 1002 (1). doi:10.3847/1538-4357/ae57a9. Bibcode: 2026ApJ..1002....4B.
- ↑ Bodenheimer, P.; Stevenson, D.; Lissauer, J.; D'Angelo, G. (2018). "New Formation Models for the Kepler-36 System". The Astrophysical Journal 868 (2): id. 138 (17 pp.). doi:10.3847/1538-4357/aae928. Bibcode: 2018ApJ...868..138B.
- ↑ Vissapragada, Shreyas et al. (2020). "Diffuser-assisted Infrared Transit Photometry for Four Dynamically Interacting Kepler Systems". The Astronomical Journal 159 (3). doi:10.3847/1538-3881/ab65c8. Bibcode: 2020AJ....159..108V.
Cite error: <ref> tag with name "Gaia DR3" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Roman1987" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "shevchenko2020" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Simbad" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "ucac4" defined in <references> is not used in prior text.
External links
 |  |
