Upsilon Geminorum
Evolved red giant star in the constellation Gemini
From Wikipedia, the free encyclopedia
Upsilon Geminorum, Latinized from υ Geminorum, is a star in the constellation Gemini. It has an apparent visual magnitude of 4.04,[2] which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 12.88 mas,[1] it is around 253 light years from the Sun. There is a visual companion: a magnitude 13.20 star located at an angular separation of 55.20″ along a position angle of 40°, as of 2008.[10]
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Gemini |
| Right ascension | 07h 35m 55.35001s[1] |
| Declination | +26° 53′ 44.6802″[1] |
| Apparent magnitude (V) | 4.04[2] (4.04 - 4.08[3]) |
| Characteristics | |
| Spectral type | M0 III[4] |
| U−B color index | +1.96[2] |
| B−V color index | +1.54[2] |
| Variable type | suspected[3] |
| Astrometry | |
| Radial velocity (Rv) | −21.61±0.19[5] km/s |
| Proper motion (μ) | RA: −32.841 mas/yr[1] Dec.: −106.002 mas/yr[1] |
| Parallax (π) | 12.8761±0.2288 mas[1] |
| Distance | 253 ± 5 ly (78 ± 1 pc) |
| Absolute magnitude (MV) | −0.53[6] |
| Details | |
| Mass | 1.52[7] M☉ |
| Radius | 39.62+0.74 −0.76[8] R☉ |
| Luminosity | 369.6±18.5[8] L☉ |
| Surface gravity (log g) | 1.0[5] cgs |
| Temperature | 4,019±38[8] K |
| Metallicity [Fe/H] | 0.17[7] dex |
| Rotational velocity (v sin i) | 5.9[5] km/s |
| Age | 3.53[7] Gyr |
| Other designations | |
| υ Gem, 69 Geminorum, BD+27°1424, FK5 1196, HD 60522, HIP 36962, HR 2905, SAO 79533.[9] | |
| Database references | |
| SIMBAD | data |
This is an evolved red giant star with a stellar classification of M0 III.[4] It is estimated to have 1.52[7] times the mass of the Sun, but has expanded to 40[8] times the Sun's radius. The star is spinning with a projected rotational velocity of 5.9 km/s[5] and is about 3.53[7] billion years old. Upsilon Geminorum is radiating 370 times the solar luminosity from its outer atmosphere at an effective temperature of 4,019 K.[8]
Based upon the motion of this star through space, Upsilon Geminorum is a member of the Wolf 630 moving group. This is a set of stars centered on Wolf 630 that are moving nearly in parallel and have an age of around 2.7±0.5 billion years. They may be former members of a dissolved open cluster.[11]