  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 23h 39m 08.33195s[1] |
| Declination | +50° 28′ 18.2328″[1] |
| Apparent magnitude (V) | 5.350[2] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B9 Ve[4] |
| B−Vcolor index | −0.110[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.9±2.2[5] km/s |
| Proper motion (μ) | RA: −17.222[1]mas/yr Dec.: −1.739[1]mas/yr |
| Parallax (π) | 7.8893±0.1288 mas[1] |
| Distance | 413 ± 7 ly (127 ± 2 pc) |
| Details | |
| Mass | 3.09±0.06[3] M☉ |
| Luminosity | 146.6+14.1 −12.9[3] L☉ |
| Surface gravity (log g) | 3.632±0.014[2] cgs |
| Temperature | 10,351±50[2] K |
| Rotational velocity (v sin i) | 183[3] km/s |
| Other designations | |
| 18 And,BD+49°4180,FK5 3897,HD 222304,HIP 116709,HR 8967,SAO 35642,PPM 42060[6] | |
| Database references | |
| SIMBAD | data |
18 Andromedae, abbreviated18 And, is a single[7]star in the northernconstellation ofAndromeda.18 Andromedae is theFlamsteed designation. It is visible to the naked eye with anapparent visual magnitude of 5.350.[2] The annualparallax shift of7.9 mas[1] can be used to estimate a distance of 413 light years. It is moving further from the Earth with a heliocentricradial velocity of +10 km/s.[5]
This is aB-type main-sequence star with astellar classification of B9 Ve,[4] where the 'e' notation indicates this is aBe star. Thestellar spectrum of 18 And displays anemission line in the hydrogenBrackett series due to a dense gaseous circumstellar envelope.[4] The star is spinning rapidly with aprojected rotational velocity of 183 km/s and has about three times themass of the Sun. It is radiating 147 times theSun's luminosity[3] from itsphotosphere at aneffective temperature of 10,351 K.[2]
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