HD 31975
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Mensa |
| Right ascension | 04h 53m 05.6446s |
| Declination | −72° 24′ 27.6449″ |
| Apparent magnitude (V) | 6.28 |
| Characteristics | |
| Spectral type | F9 V Fe−0.5 |
| U−B color index | +0.01 |
| B−V color index | +0.52 |
| Astrometry | |
| Radial velocity (Rv) | 26.8 ± 0.3 km/s |
| Proper motion (μ) | RA: −46.178 mas/yr Dec.: +270.916 mas/yr |
| Parallax (π) | 30.8217±0.0217 mas |
| Distance | 105.82 ± 0.07 ly (32.44 ± 0.02 pc) |
| Absolute magnitude (MV) | +3.72 |
| Details | |
| Mass | 1.13 M☉ |
| Radius | 1.46 R☉ |
| Luminosity | 2.77 L☉ |
| Surface gravity (log g) | 4.16 cgs |
| Temperature | 6.165 K |
| Metallicity [Fe/H] | 0.00 dex |
| Rotational velocity (v sin i) | 6 km/s |
| Age | 3.5 Gyr |
| Other designations | |
| 15 G. Mensae, CD−72°231, CPD−72°332, GC 6031, HD 31975, HIP 22717, HR 1606, SAO 256139, WDS J04531-7225A | |
| Database references | |
| SIMBAD | data |
HD 31975 (HR 1606) is a star situated in the southern circumpolar constellation Mensa. It has an apparent magnitude of 6.28, which is near the threshold of naked eye visibility. It is relatively close at a distance of about 106 light years but is receding with a heliocentric radial velocity of 26.9 km/s.
HD 31975 has a stellar classification of F9 V Fe−0.5, indicating that it is a F-type main-sequence star with a mild under abundance of iron in its atmosphere. At present it has 120% the mass of the Sun and 146% the radius of the Sun. It shines at double the luminosity of the Sun from its photosphere at an effective temperature of 6,165 K, giving it a yellow-white glow. HD 31975 has a similar metallicity to the Sun and at an age of 3.5 billion years it spins slowly with a projected rotational velocity of 6 km/s.
The Washington Double Star Catalog lists a faint M5 companion 16.5" away, which is related to the star.