HD 3765
K-type main-sequence star in the constellation Andromeda
From Wikipedia, the free encyclopedia
HD 3765 is a single K-type main-sequence star in the constellation of Andromeda, near the Andromeda Galaxy in the sky. Its surface temperature is about 5076 K.[6] HD 3765 has an orange hue and is too faint to be seen with the naked eye, but can be seen with a small telescope.[8] It has an apparent visual magnitude of 7.34. Based upon parallax measurements, it is located 58.4 light-years from the Sun. The object is drifting towards the Sun with a radial velocity of −63.3 km/s.[2]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda[1] |
| Right ascension | 00h 40m 49.270s[2] |
| Declination | +40° 11′ 13.82″[2] |
| Apparent magnitude (V) | 7.34[3] |
| Characteristics | |
| Evolutionary stage | Main sequence[3] |
| Spectral type | K2V[4] |
| Astrometry | |
| Radial velocity (Rv) | −63.33±0.12[2] km/s |
| Proper motion (μ) | RA: 356.318 mas/yr[2] Dec.: −669.205 mas/yr[2] |
| Parallax (π) | 55.8412±0.0235 mas[2] |
| Distance | 58.41 ± 0.02 ly (17.908 ± 0.008 pc) |
| Absolute magnitude (MV) | 6.16[3] |
| Details | |
| Mass | 0.852+0.020 −0.044[5] M☉ |
| Radius | 0.79±0.02[5] R☉ |
| Luminosity | 0.383±0.011[6] L☉ |
| Surface gravity (log g) | 4.58±0.03[5] cgs |
| Temperature | 5076+115 −160[6] K |
| Metallicity [Fe/H] | 0.25[3] dex |
| Rotational velocity (v sin i) | 2[3] km/s |
| Other designations | |
| BD+39 154, GJ 28, HD 3765, HIP 3206, SAO 54074, LHS 1125, Wolf 12[7] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
Planetary system
HD 3765 has one known exoplanet, discovered in 2021 by the radial velocity method.[9] Prior to this discovery, it had been used as a radial velocity standard star.[10] The planet, HD 3765 b, orbits with a period of 3.3 years at a distance of 2.1 AU, and is not in the habitable zone. It is a gas giant with a minimum mass of 0.173 Jupiter masses,[9] and a predicted radius 0.764 times that of Jupiter.[11]
During observations of the variable star EG Andromedae in 1971, a possible eclipse of HD 3765 (which was used as a comparison star) was observed. It was proposed that this might be due to a transiting planet the size of Jupiter. The presence of eclipses has not been confirmed, and the observation could have been due to intrinsic variability, or in error.[12]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.173+0.014 −0.013 MJ |
2.108+0.032 −0.033 |
1211+15 −16 |
0.298+0.078 −0.071 |
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