Kepler-70b
| Exoplanet | List of exoplanets | |
|---|---|---|
| 300px |
||
| Parent star | ||
| Star | Kepler-70 | |
| Constellation | Cygnus | |
| Right ascension | (α) | 19h 45m 25s |
| Declination | (δ) | +41° 5′ 34″ |
| Apparent magnitude | (mV) | 14.87 [1] |
| Distance | 3849 ± 310 ly (1180 ± 95 [2] pc) |
|
| Spectral type | sdB | |
| Mass | (m) | 0.496 ± 0.002 M☉ |
| Radius | (r) | 0.203 ± 0.007 R☉ |
| Temperature | (T) | 27730 ± 270 K |
| Orbital elements | ||
| Semi-major axis | (a) | 0.006 AU (0.897 Gm) |
| Orbital period | (P) | 0.2401 ± 0.000004 d |
| Inclination | (i) | ~65° |
| Physical characteristics | ||
| Minimum mass | (m sin i) | 0.440 M⊕ |
| Radius | (r) | 0.759 [note 1][2] R⊕ |
| Density | (ρ) | 5500 kg m−3 |
| Stellar flux | (F⊙) | 640000 ⊕ |
| Temperature | (T) | 7,143 K (6,870 °C; 12,398 °F) |
| Discovery information | ||
| Discovery date | 12/22/2011 (announced) [3] | |
| Discoverer(s) | Charpinet et al.[3] | |
| Discovery method | Reflection/emission modulations | |
| Discovery site | Kepler telescope | |
| Discovery status | Published | |
| Other designations | ||
| Database references | ||
| Extrasolar Planets Encyclopaedia |
data | |
| SIMBAD | data | |
| Exoplanet Archive | data | |
| Open Exoplanet Catalogue | data | |
Kepler-70b (formerly called KOI-55.01;[3] sometimes listed as KOI-55 b) is a planet discovered orbiting the subdwarf B star (sdB) Kepler-70. It orbits its host along with another planet, Kepler-70c, both of which orbit very close to their host star. Kepler-70b completes one orbit around its star in just 5.76 hours, one of the shortest orbital periods of any exoplanetary system yet discovered, only second to PSR 1719-14 b with a period of 2.2 hours. It is also the hottest exoplanet as of mid-2013, with a surface temperature of 7,143 K (6,870 °C; 12,398 °F).[4] Its density is 5500 kg/m3 which is not much different from Earth.[5]
Kepler-70c passes 240,000 km away from Kepler-70b during their closest approach. This is currently the closest recorded approach between planets.
According to the main author of the paper in Nature which announced the discovery of the two planets, Stephane Charpinet, the two planets "probably plunged deep into the star’s envelope during the red giant phase, but survived.”[6] However, this is not the first sighting of planets orbiting a post-red giant star - numerous pulsar planets have been observed, but no planet has been found with such a short period around any star, whether or not on the main sequence.
Origins
The two planets were most likely gas giants which spiraled inward toward their host star, which subsequently became a red giant, vaporizing much of the planets except for parts of their solid cores, which are now orbiting the sdB star.[6] According to the Extrasolar Planets Encyclopedia, the star left the red giant stage 18.4 million years ago.[2]
See also
Notes
- ↑ Assuming an albedo of 0.1.
External links
References
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 2.0 2.1 2.2 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ 3.0 3.1 3.2 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.
- ↑ 6.0 6.1 Lua error in package.lua at line 80: module 'strict' not found.
