03h40m49.5246s, +31° 49′ 34.6489″03h40m 49.5246s[1]
+31° 49′ 34.6489″[1]
8.78[2]
Characteristics
K0[2]
Radial velocity (Rv)
8.26[1] km/s
Proper motion (μ)
RA: 40.576[1] mas/yr
Dec.: −94.254[1] mas/yr
Parallax (π)
106.4 ± 0.4 ly
(32.6 ± 0.1 pc)
Details[5]
0.75±0.02 M☉
0.70±0.02 R☉
Surface gravity (log g)
4.57±0.04 cgs
5175±15 K
Metallicity [Fe/H]
−0.35±0.02 dex
Rotational velocity (v sin i)
1.73[3] km/s
4.14±3.63 Gyr
Database references
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]
In 2011 a transiting superjovian planet or brown dwarf b was detected on an extremely 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]
The HD 22781 planetary system[3]
Companion
(in order from star)
≥13.65±0.97 MJ
1.167±0.039
528.07±0.14
0.8191±0.0023
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Other
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