Omega Serpentis
Omega Serpentis (ω Ser, ω Serpentis) is a solitary star within the Serpens Caput part of the equatorial constellation of Serpens. It is visible to the naked eye with an apparent visual magnitude of +5.22. Based upon an annual parallax shift of 11.93 mas as seen from Earth, it is located about 273 light years from the Sun. At that distance, its visual magnitude is diminished by an extinction factor of 0.19 due to interstellar dust. It is a member of the Ursa Major Stream, lying among the outer parts, or corona, of this moving group of stars that roughly follow a common heading through space.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15h 50m 17.54635s |
| Declination | +02° 11′ 47.4362″ |
| Apparent magnitude (V) | +5.22 |
| Characteristics | |
| Spectral type | G8 III |
| U−B color index | +0.805 |
| B−V color index | +1.02 |
| Astrometry | |
| Radial velocity (Rv) | −3.11±0.08 km/s |
| Proper motion (μ) | RA: +29.15 mas/yr Dec.: −47.31 mas/yr |
| Parallax (π) | 11.93 ± 0.28 mas |
| Distance | 273 ± 6 ly (84 ± 2 pc) |
| Absolute magnitude (MV) | +0.49 |
| Details | |
| Mass | 1.20±0.24 M☉ |
| Radius | 10.48±0.52 R☉ |
| Luminosity | 69 L☉ |
| Surface gravity (log g) | 2.88±0.03 cgs |
| Temperature | 4,797±16 K |
| Metallicity [Fe/H] | −0.26±0.02 dex |
| Rotational velocity (v sin i) | 0.99±0.98 km/s |
| Age | 3.94±2.16 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
With an estimated age of around four billion years, Omega Serpentis is an evolved G-type giant star with a stellar classification of G8 III. It is a red clump giant, which means that it is generating energy at its core through the nuclear fusion of helium. The star has an estimated 120% of the Sun's mass but has expanded to 10.48 times the radius of the Sun. It is radiating 69 times the solar luminosity from its photosphere at an effective temperature of 4,797 K.