Pi Eridani
Red giant star in the constellation Eridanus
From Wikipedia, the free encyclopedia
Pi Eridani, Latinized from π Eridani, is a star in the constellation Eridanus. It has an apparent visual magnitude of 4.40,[2] which is bright enough to be seen on a dark, clear night. Based upon parallax measurements, it is located roughly 480 light years from the Sun.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Eridanus |
| Right ascension | 03h 46m 08.53581s[1] |
| Declination | −12° 06′ 05.7282″[1] |
| Apparent magnitude (V) | 4.40[2] (4.38 - 4.44[3]) |
| Characteristics | |
| Evolutionary stage | asymptotic giant branch[4] |
| Spectral type | M1 III[5] |
| U−B color index | +1.96[2] |
| B−V color index | +1.61[2] |
| Variable type | Lb?[3] |
| Astrometry | |
| Radial velocity (Rv) | 45.2±0.1[6] km/s |
| Proper motion (μ) | RA: +55.98[1] mas/yr Dec.: +59.28[1] mas/yr |
| Parallax (π) | 6.78±0.53 mas[1] |
| Distance | 480 ± 40 ly (150 ± 10 pc) |
| Absolute magnitude (MV) | −1.40[7] |
| Details | |
| Radius | 77[8] R☉ |
| Luminosity | 1,123[9] L☉ |
| Temperature | 3,841[9] K |
| Other designations | |
| π Eridani, π Eri, 26 Eridani, BD−12°707, HD 23614, HIP 17593, HR 1162, SAO 149158[10] | |
| Database references | |
| SIMBAD | data |
This is an evolved red giant star with a stellar classification of M1 III,[5] and is currently on the asymptotic giant branch.[4] It is a slow irregular variable type LB that can increase in magnitude up to 4.38.[3][11] The measured angular diameter of this star is 4.8±0.5 mas.[12] At the estimated distance of Pi Eridani, this yields a physical size of about 77 times the radius of the Sun.[8] It shines with 1,123[9] times the luminosity of the Sun from an outer atmosphere at an effective temperature of 3,841 K.[9]
