HD 203857
From Wikipedia, the free encyclopedia
|
Rendering of HD 203857 and its hypothetical planet |
|
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Cygnus |
| Right ascension | 21h 21m 46.81s |
| Declination | +37° 08′ 10.2″ |
| Apparent magnitude (V) | 6.45 |
| Characteristics | |
| Spectral type | K5III |
| Astrometry | |
| Distance | ≈919.32 ly (282±50 pc) |
| Details | |
| Mass | 1.7 [1] M☉ |
| Radius | 46-50[1] R☉ |
| Luminosity | 513[1] L☉ |
| Temperature | 3980[1] K |
| Other designations | |
|
HIP 105637, CSI+36 4543 1, HIC 105637, SAO 71280, AG+37 2110, GC 29966, HR 8193, SKY# 40762, BD+36 4543, GCRV 13462, IDS 21197+3655 A, TYC 2715-3976-1, BDS 10966 A, GSC 02715-03976, 2MASS J21234838+3721052, CCDM J21237+3722A, HD 203857, PPM 86485
|
|
HD 203857 is a late type K giant star in the constellation Cygnus, located nearly 920 light years away from Sun. The star is thought to form a visual binary system with the F-type bright giant BDS 10966 A, though it's likely they are actually not gravitationally bound. The star likely hosts an extrasolar planet, though yet unconfirmed.
[edit] Substellar companion
Okayama Planet Search team has published a paper in late 2008 reporting investigations on radial velocity variations observed for a set of evolved stars, announcing possible detection of a substellar companion orbiting the giant star HD 203857.[1] Orbital period is estimated 2.3 years, but planet has still to be confirmed.
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity |
|---|---|---|---|---|
| b (unconfirmed) | ≥8.1 MJ | 2.1 | 836.8 | 0.3 |
[edit] References
- ^ a b c d e Toyota et al. (2008). "Radial Velocity Search for Extrasolar Planets in Visual Binary Systems". Publications of the Astronomical Society of Japan 61 (1): 19–28. Bibcode 2009PASJ...61...19T.
[edit] External links
 |
This variable star–related article is a stub. You can help Wikipedia by expanding it. |
 |
This giant star-related article is a stub. You can help Wikipedia by expanding it. |
 |
This extrasolar planet related article is a stub. You can help Wikipedia by expanding it. |
