13 Andromedae
Star in the constellation Andromeda
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13 Andromedae, abbreviated 13 And, is a single,[11] blue-white hued variable star[4] in the northern constellation of Andromeda. 13 Andromedae is the Flamsteed designation, while it bears the variable star designation V388 Andromedae. With a typical apparent visual magnitude of around 5.75,[1] it is dimly visible to the naked eye under good seeing conditions. The distance to this star can be directly estimated from its annual parallax shift of 10.4 mas,[2] yielding a range of 315 light years. At that distance, its brightness is diminished by an extinction of 0.13 magnitude due to interstellar dust.[6] The star is moving closer to the Earth with a heliocentric radial velocity of −8 km/s.[5]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda[1] |
| Right ascension | 23h 27m 07.40s[2] |
| Declination | +42° 54′ 43.2″[2] |
| Apparent magnitude (V) | 5.75[1] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | B9 III or B9 Mn[3] |
| B−V color index | −0.007±0.004[1] |
| Variable type | α2 CVn[4] |
| Astrometry | |
| Radial velocity (Rv) | −8.1±1.6[5] km/s |
| Proper motion (μ) | RA: +87.132[2] mas/yr Dec.: +17.127[2] mas/yr |
| Parallax (π) | 10.3618±0.0465 mas[2] |
| Distance | 315 ± 1 ly (96.5 ± 0.4 pc) |
| Absolute magnitude (MV) | 0.98[6] |
| Details | |
| Mass | 2.5[7] M☉ |
| Radius | 2.4[7] R☉ |
| Luminosity | 48[7] L☉ |
| Surface gravity (log g) | 4.08[7] cgs |
| Temperature | 9,790[7] K |
| Rotational velocity (v sin i) | 75[8] km/s |
| Age | 339[6] Myr |
| Other designations | |
| 13 And, V388 Andromedae, BD+42°4672, HD 220885, HIP 115755, HR 8913, SAO 53039, PPM 64250[9] | |
| Database references | |
| SIMBAD | data |
The variability of 13 Andromedae was first detected in Hipparcos satellite data, and it received its variable star designation in 1999.[12][13]
This is a magnetic chemically peculiar star that has been assigned stellar classifications of B9 III or B9 Mn.[3] It is a variable star of the Alpha2 Canum Venaticorum type, ranging in magnitude from 5.73 down to 5.77[4] with a period of 1.47946 days.[3] The star has a high rate of spin, showing a projected rotational velocity of 75 km/s.[8] 13 Andromedae is around 339 million years old[6] and shines with 48 times the Sun's luminosity.[7]