7 Andromedae
7 Andromedae (abbreviated 7 And) is a single, yellow-white hued star in the northern constellation of Andromeda. 7 Andromedae is the Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.52, and is located 79.6 light years from Earth, based on an annual parallax shift of 41 mas. The star is moving further from the Sun with a heliocentric radial velocity of 12 km/s.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 12m 33.00460s |
| Declination | +49° 24′ 22.3299″ |
| Apparent magnitude (V) | 4.52 |
| Characteristics | |
| Spectral type | F1V |
| U−B color index | +0.01 |
| B−V color index | +0.28 |
| Astrometry | |
| Radial velocity (Rv) | 12.10±1 km/s |
| Proper motion (μ) | RA: 89.292 mas/yr Dec.: 96.696 mas/yr |
| Parallax (π) | 40.9812 ± 0.2307 mas |
| Distance | 79.6 ± 0.4 ly (24.4 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.58 |
| Details | |
| Mass | 1.6 ± 0.1 M☉ |
| Radius | 1.71 ± 0.02 R☉ |
| Luminosity | 7.8 ± 0.6 L☉ |
| Surface gravity (log g) | 4.16 ± 0.02 cgs |
| Temperature | 7,380 ± 90 K |
| Metallicity [Fe/H] | -0.02 ± 0.08 dex |
| Rotational velocity (v sin i) | 61 ± 6 km/s |
| Age | 1120 ± 30 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is an ordinary F-type main-sequence star with a stellar classification of F1V, which indicates it is generating energy from hydrogen fusion at its core. This energy is being radiated from its photosphere at the rate of 7.8 times the Sun's luminosity with an effective temperature of 7,380 K. 7 Andromedae is 1.1 billion years old and is spinning with a projected rotational velocity of 61 km/s.
Within Andromeda it is at the middle of a northerly chain asterism – 8, 11 are further south-westward, with 5, then 3 Andromedae in the other direction. This star is the closest of these five, all of quite great apparent magnitude.