Upsilon Andromedae
Star in the constellation Andromeda / From Wikipedia, the free encyclopedia
This article is about υ Andromedae. For the variable star, see U Andromedae.
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.
Quick Facts Observation data Epoch J2000.0 Equinox J2000.0, Apparent magnitude (V) ...
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Andromeda |
υ And A | |
Right ascension | 01h 36m 47.84154s[1] |
Declination | +41° 24′ 19.6514″[1] |
Apparent magnitude (V) | 4.10[2] |
υ And D[lower-alpha 1] | |
Right ascension | 01h 36m 50.40476s[3] |
Declination | +41° 23′ 32.1228″[3] |
Characteristics | |
Spectral type | F8V[4] + M4.5V[5] |
Apparent magnitude (B) | 4.63[6] |
U−B color index | 0.06 |
B−V color index | 0.54 |
V−R color index | 0.30[7] |
R−I color index | 0.30[7] |
Astrometry | |
υ And A | |
Radial velocity (Rv) | −28.59±0.08[8] km/s |
Proper motion (μ) | RA: −171.892±0.270[1] mas/yr Dec.: −381.815±0.130[1] mas/yr |
Parallax (π) | 74.1940 ± 0.2083 mas[1] |
Distance | 44.0 ± 0.1 ly (13.48 ± 0.04 pc) |
Absolute magnitude (MV) | 3.44±0.02[9] |
υ And D[lower-alpha 1] | |
Proper motion (μ) | RA: −172.437±0.031[3] mas/yr Dec.: −383.824±0.027[3] mas/yr |
Parallax (π) | 74.1815 ± 0.0356 mas[3] |
Distance | 43.97 ± 0.02 ly (13.480 ± 0.006 pc) |
Details | |
υ And A | |
Mass | 1.27±0.06[9] M☉ |
Radius | 1.57±0.03[10] R☉ |
Luminosity | 3.1±0.1[10] L☉ |
Surface gravity (log g) | 4.0±0.1[9] cgs |
Temperature | 6614±77[10] K |
Metallicity [Fe/H] | 0.08[10] dex |
Rotation | 7.3±0.04 d[11] |
Rotational velocity (v sin i) | 9.5±0.8[9] km/s |
Age | 3.12 ± 0.2[7] Gyr |
υ And D[lower-alpha 1] | |
Mass | 0.2[5] M☉ |
Other designations | |
Database references | |
SIMBAD | data |
υ And D | |
Data sources: | |
Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) |
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As of 2015[update], 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.