Kepler-70
| Observation data Epoch Equinox |
|
|---|---|
| Constellation | Cygnus[1][note 1] |
| Right ascension | 19h 45m 25s[1] |
| Declination | +41° 5′ 34″[1] |
| Apparent magnitude (V) | 14.87[2] |
| Characteristics | |
| Spectral type | sdB[1] |
| Apparent magnitude (U) | 13.80[2] |
| Apparent magnitude (B) | 14.71[2] |
| Apparent magnitude (R) | 15.43[2] |
| Apparent magnitude (I) | 15.72[2] |
| Apparent magnitude (J) | 15.36[2] |
| Apparent magnitude (H) | 15.59[2] |
| Astrometry | |
| Distance | 3849 ± 310[1] ly (1180 ± 95[1] pc) |
| Details | |
| Mass | 0.496 ± 0.002[1] M☉ |
| Radius | 0.203 ± 0.007[1] R☉ |
| Luminosity (bolometric) | 22.9 ± 3.1 L☉ |
| Temperature | 27,730 ± 260[1] K |
| Other designations | |
Kepler-70, formerly known as KOI-55, is a star in the constellation Cygnus with an apparent visual magnitude of 14.87.[2] This is too faint to be seen with the naked eye; viewing it requires a telescope with an aperture of Lua error in Module:Convert at line 1851: attempt to index local 'en_value' (a nil value). or more.[3]
A subdwarf B star, KOI-55 passed through the red giant stage some 18.4 million years ago. In its present day state, it is fusing helium in its core. Once it runs out of helium it will contract to form a white dwarf. It has a relatively small radius of about 0.2 times the Sun's radius; white dwarfs are generally much smaller.[4] The star is host to a planetary system with two planets, KOI-55.01 and KOI-55.02.[5]
Planetary system
On December 26, 2011, evidence for two extremely short-period planets was announced. They were detected by the reflection of starlight caused by the planets themselves, rather than through a variation in apparent stellar magnitude caused by them transiting the star.
The measurements also suggested a smaller body between the two confirmed planets; this remains unconfirmed.
Orbits of Kepler-70b and Kepler-70c have 7:10 orbital resonance and have the closest approach between planets of any known planetary system.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 0.440 M⊕ | 0.0060 | 0.2401 | — | 20–80, likely 65 [note 2]° | 0.759 R⊕ |
| KOI-55.03 (unconfirmed) | 0.222 M⊕ | 0.0065 | — | — | — | 0.605 R⊕ |
| c | 0.655 M⊕ | 0.0076 | 0.34289 | — | 20–80, likely 65° | 0.867 R⊕ |
Notes
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 5.0 5.1 Lua error in package.lua at line 80: module 'strict' not found.
