Upsilon 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.
| 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±0.270 mas/yr Dec.: −381.815±0.130 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±0.031 mas/yr Dec.: −383.824±0.027 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 | 1.27±0.06 M☉ |
| Radius | 1.480±0.087 R☉ |
| Luminosity | 3.57 L☉ |
| Surface gravity (log g) | 4.0±0.1 cgs |
| Temperature | 6,213±44 K |
| Metallicity [Fe/H] | 0.09±0.06 dex |
| Rotation | 7.3±0.04 d |
| Rotational velocity (v sin i) | 9.5±0.8 km/s |
| Age | 3.12 ± 0.2 Gyr |
| υ And D | |
| Mass | 0.2 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
| υ And D | |
| Data sources: | |
| Hipparcos Catalogue, CCDM (2002), Bright Star Catalogue (5th rev. ed.) | |
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.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.