Upsilon Andromedae
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Andromeda |
| υ And A | |
| Right ascension | 01h 36m 47.84154s |
| Declination | +41° 24′ 19.6514″ |
| Apparent magnitude (V) | 4.10 |
| υ And D | |
| Right ascension | 01h 36m 50.40476s |
| Declination | +41° 23′ 32.1228″ |
| Characteristics | |
| Spectral type | F8V + M4.5V |
| Apparent magnitude (B) | 4.63 |
| U−B color index | 0.06 |
| B−V color index | 0.54 |
| V−R color index | 0.30 |
| R−I color index | 0.30 |
| Astrometry | |
| υ And A | |
| Radial velocity (Rv) | −28.59±0.08 km/s |
| Proper motion (μ) | RA: −171.892 mas/yr Dec.: −381.815 mas/yr |
| Parallax (π) | 74.1940±0.2083 mas |
| Distance | 44.0 ± 0.1 ly (13.48 ± 0.04 pc) |
| Absolute magnitude (MV) | 3.44±0.02 |
| υ And D | |
| Proper motion (μ) | RA: −172.437 mas/yr Dec.: −383.824 mas/yr |
| Parallax (π) | 74.1815 ± 0.0356 mas |
| Distance | 43.97 ± 0.02 ly (13.480 ± 0.006 pc) |
| Details | |
| υ And A | |
| Mass | 1.23+0.03 −0.09 M☉ |
| Radius | 1.57±0.03 R☉ |
| Luminosity | 3.1±0.1 L☉ |
| Habitable zone inner limit | 1.43±0.05 AU |
| Habitable zone outer limit | 2.84±0.08 AU |
| Surface gravity (log g) | 4.0±0.1 cgs |
| Temperature | 6,614±77 K |
| Metallicity [Fe/H] | 0.08 dex |
| Rotation | 7.3±0.04 d |
| Rotational velocity (v sin i) | 9.5±0.8 km/s |
| Age | 4.02+1.91 −0.82 Gyr |
| υ And D | |
| Mass | 0.190±0.006 M☉ |
| Radius | 0.222±0.007 R☉ |
| Luminosity | 0.00391±0.00011 L☉ |
| Temperature | 3,188±106 K |
| Other designations | |
| Titawin, 50 Andromedae, BD+40 332, CCDM 01367+4125, FK5 1045, GC 1948, GCTP 331.00, Gl 61, HD 9826, HIP 7513, HR 458, LTT 10561, SAO 37362, PPM 44216, WDS 01368+4124A, 2MASS J01364784+4124200, Gaia DR2 348020448377061376 | |
| Database references | |
| SIMBAD | data |
| υ And D | |
| Exoplanet Archive | data |
Upsilon Andromedae (υ Andromedae, abbreviated Upsilon And, υ And) is a binary star located 44 light-years from Earth in the constellation of Andromeda. The system consists of an F-type main-sequence star (designated υ Andromedae A, officially named Titawin in the Amazigh language /tɪtəˈwiːn/) and a smaller red dwarf.
As of 2015, three extrasolar planets (designated Upsilon Andromedae b, c, d; named Saffar, Samh and Majriti, respectively) are believed to orbit υ Andromedae A. All three are likely to be jovian planets that are comparable in size to Jupiter. This was both the first multiple-planet system to be discovered around a main-sequence star, and the first multiple-planet system known in a multiple-star system.