HD 22781
Coordinates: 
03h 40m 49.5246s, +31° 49′ 34.6489″
03h 40m 49.5246s, +31° 49′ 34.6489″| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Perseus |
| Right ascension | 03h 40m 49.5246s[1] |
| Declination | +31° 49′ 34.6489″[1] |
| Apparent magnitude (V) | 8.78[2] |
| Characteristics | |
| Evolutionary stage | main-sequence star[3]
|
| Spectral type | K0[2] |
| Details Gyr | |
| Database references | |
| SIMBAD | data |
HD 22781, is a single star about 106 light-years away. It is a K-type main-sequence star. The star’s age is poorly constrained at 4.14±3.63 billion years, but is likely similar to that of the Sun.[5] HD 22781 is heavily depleted in heavy elements, having just 45% of Sun's concentration of iron,[2] yet is comparatively rich in carbon, having 90% of Sun`s abundance.[5]
An imaging survey in 2012 has failed to find any stellar companions, suggesting HD 22781 is a single star.[6]
Planetary system
In 2011 a
eccentric orbit.[3] It is located just outside of the conservative habitable zone of the parent star.[7] Planets around such metal-poor stars are rare; the only three known similar cases are HD 111232 and HD 181720.[8]
In 2012, a radial velocity data review indicated there are no additional giant planets in the system.[9]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥13.65±0.97 MJ | 1.167±0.039 | 528.07±0.14 | 0.8191±0.0023 | — | — |
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