View of the Andromeda Galaxy, with HD 3765 circled in red. The star is much closer than Andromeda, within the Milky Way galaxy. | |
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 |
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]
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 | — | — |