HD 50281
Binary star in the constellation Monoceros
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HD 50281 is a star in the equatorial constellation of Monoceros. It is orange in hue with an apparent visual magnitude of 6.58,[1] which lies at or below the typical limit of visibility to the naked eye. The star is located at a distance of 28.5 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −7.2 km/s.[4]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Monoceros[1] |
| Right ascension | 06h 52m 18.05045s[2] |
| Declination | −05° 10′ 25.3662″[2] |
| Apparent magnitude (V) | 6.58[1] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | K3.5 V[3] |
| B−V color index | 1.071±0.008[1] |
| Astrometry | |
| Radial velocity (Rv) | −7.20±0.15[4] km/s |
| Proper motion (μ) | RA: −543.616[2] mas/yr Dec.: −3.491[2] mas/yr |
| Parallax (π) | 114.2968±0.0465 mas[2] |
| Distance | 28.54 ± 0.01 ly (8.749 ± 0.004 pc) |
| Absolute magnitude (MV) | 6.87[5] |
| Details | |
| Mass | 0.79[6] M☉ |
| Radius | 0.73+0.01 −0.02[2] R☉ |
| Luminosity | 0.225[2] L☉ |
| Surface gravity (log g) | 4.64[6] cgs |
| Temperature | 4,712±8.5[7] K |
| Metallicity [Fe/H] | +0.01[8] dex |
| Rotational velocity (v sin i) | 5.5[6] km/s |
| Age | 1.88[6] Gyr |
| Other designations | |
| 88 G. Monocerotis, BD−05°1844, GJ 250, HD 50281, HIP 32984, HR 2534, SAO 133805, WDS J06523−0510, LFT 494, LHS 1875, LTT 2662[9] | |
| Database references | |
| SIMBAD | A |
| B | |
This object is an ordinary K-type main-sequence star with a stellar classification of K3.5 V.[3] It is nearly two billion years old and is spinning with a projected rotational velocity of 5.5 km/s.[6] The metallicity of this star – what astronomers term the abundance of elements with atomic numbers greater than helium – is near solar. The star has 79%[6] of the mass of the Sun and 73%[2] of the Sun's radius. It is radiating 22.5%[2] of the luminosity of the Sun from its photosphere at an effective temperature of 4,712 K.[7]
A magnitude 10.16 common proper motion companion,[10] designated component B, is located at an angular separation of 58.8″ along a position angle of 181° from the primary, as of 2015.[10] This is a suspected binary star system[11] with components of individual visual magnitude 10.6 and 11.1,[10] and a class of M2.5 V.[12] The coordinates of this companion are a source of X-ray emission.[13] A third companion, magnitude 14.04 component C, lies at a separation of 9.6″ from component B.[10]