Pi Andromedae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Andromeda |
| Right ascension | 00h 36m 52.85132s |
| Declination | +33° 43′ 09.6363″ |
| Apparent magnitude (V) | 4.36 (4.9/5.3) |
| Characteristics | |
| Spectral type | B5 V (B5 V + B5 V) |
| U−B color index | –0.55 |
| B−V color index | –0.16 |
| Astrometry | |
| Radial velocity (Rv) | +8.7 km/s |
| Proper motion (μ) | RA: 14.669(118) mas/yr Dec.: −3.385(93) mas/yr |
| Parallax (π) | 5.6563±0.1474 mas |
| Distance | 580 ± 20 ly (177 ± 5 pc) |
| Orbit | |
| Period (P) | 143.53±0.06 d |
| Semi-major axis (a) | 6.69±0.05 mas |
| Eccentricity (e) | 0.542±0.006 |
| Inclination (i) | 103.0±0.2° |
| Longitude of the node (Ω) | 94.7±0.2° |
| Periastron epoch (T) | 7717.7±0.4 |
| Argument of periastron (ω) (secondary) | 170.7±0.7° |
| Semi-amplitude (K1) (primary) | 47.50±0.53 km/s |
| Semi-amplitude (K2) (secondary) | 117.4±2.8 km/s |
| Details | |
| A | |
| Mass | 5.8 M☉ |
| Radius | 4.7 R☉ |
| Luminosity | 1,000 L☉ |
| Surface gravity (log g) | 4.10 cgs |
| Temperature | 15,000 K |
| Metallicity [Fe/H] | –0.20 dex |
| Rotational velocity (v sin i) | 25 km/s |
| Age | 80 Myr |
| B | |
| Mass | 4.8 M☉ |
| Radius | 4.7 R☉ |
| Luminosity | 1,000 L☉ |
| Temperature | 15,000 K |
| Other designations | |
| Pi And, π Andromedae, π And, 29 Andromedae, BD+32°101, FK5 18, HD 3369, HIP 2912, HR 154, SAO 54033, PPM 65480, ADS 513 | |
| Database references | |
| SIMBAD | data |
Pi Andromedae is a binary star system in the northern constellation of Andromeda. Its Bayer designation is latinized from π Andromedae, and abbreviated Pi And or π And, respectively. With an apparent visual magnitude of 4.4, it is visible to the naked eye. Based on parallax measurements, it is located at a distance of approximately 580 light-years (180 parsecs) from Earth.
The pair is classified as a blue-white B-type main sequence dwarf, with an apparent magnitude of +4.34. It is a spectroscopic binary with an orbital period of 143.5 days and an eccentricity of 0.54.
The spectroscopic binary forms a triple system with BD+32 102, a magnitude 8.6 star located 35.9 arcseconds away. At 55 arcseconds separation is an 11th magnitude companion that is just located on the same line of sight, but at a very different distance from us.