13 Monocerotis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Monoceros |
| Right ascension | 06h 32m 54.22948s |
| Declination | 07° 19′ 58.6942″ |
| Apparent magnitude (V) | 4.498 |
| Characteristics | |
| Spectral type | A0 Ib |
| U−B color index | −0.217 |
| B−V color index | +0.007 |
| Variable type | suspected |
| Astrometry | |
| Radial velocity (Rv) | +11.80 km/s |
| Proper motion (μ) | RA: -0.20 mas/yr Dec.: -3.48 mas/yr |
| Parallax (π) | 0.83±0.46 mas |
| Distance | 780 pc |
| Absolute magnitude (MV) | −4.80 |
| Details | |
| Mass | 12.0 M☉ |
| Radius | 34 R☉ |
| Surface gravity (log g) | 2.15 cgs |
| Temperature | 10,000 K |
| Metallicity [Fe/H] | −0.18 dex |
| Rotational velocity (v sin i) | 0 km/s |
| Age | 16 Myr |
| Other designations | |
| BD+07 1337, FK5 1174, GC 8506, HIP 31216, HR 2385, HD 46300, NSV 16904, SAO 114034 | |
| Database references | |
| SIMBAD | data |
13 Monocerotis (13 Mon) is a class A0 Ib (white supergiant) star in the constellation Monoceros. Its apparent magnitude is 4.5 and it is approximately 780 parsecs (2,500 ly) away.
13 Mon lies within the Monoceros OB1 stellar association, halfway between the Rosette Nebula and NGC 2264, at a distance of about 780 parsecs. It is surrounded by a small reflection nebula listed as Van den Bergh 81 (VdB 81).
13 Monocerotis has been used as a standard star for the A0 Ib spectral class.
Extended photometry of 13 Monocerotis from 1997 to 2000 shows irregular variation of up to 0.04 magnitudes and also a slight trend to become fainter over the period. All the bright A0 - A5 supergiants analysed using Hipparcos satellite data were found to be variable, but 13 Mon was the least variable.