00h01m57.6s, −06° 50′ 50.7″
| |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 00h01m 57.61947s[1] |
| Declination | −06° 00′ 50.6540″[1] |
| Apparent magnitude (V) | 4.31 – 4.41[2] |
| Characteristics | |
| Spectral type | M3 III[3] |
| B−V color index | 1.631±0.011[4] |
| Variable type | LPV,[5] LB?[2] |
| Astrometry | |
| Radial velocity (Rv) | −11.7±0.5[6] km/s |
| Proper motion (μ) | RA: 46.941 mas/yr[1] Dec.: −40.471 mas/yr[1] |
| Parallax (π) | 7.8758 ± 0.4105 mas[1] |
| Distance | 410 ± 20 ly (127 ± 7 pc) |
| Absolute magnitude (MV) | −1.20[5] |
| Details | |
| Radius | 109.2+5.46 −6.05[7] R☉ |
| Luminosity | 1,597±177[7] L☉ |
| Surface gravity (log g) | 2[8] cgs |
| Temperature | 3,490±35[7] K |
| Other designations | |
30 Psc, YY Psc, BD−06° 6345, FK5 1630, HD 224935, HIP 154, HR 9089, SAO 147042[9] | |
| Database references | |
| SIMBAD | data |
30 Piscium (HIP 154) is a solitary[10] variable star in the zodiac constellationofPisces. It is visible to the naked eye with an apparent visual magnitude of 4.37.[8] Its calculated mid-value of antiposed parallax shift as the Earth moves around the Sun of very roughly 7.88 mas, makes it around 410 light years away.[1] Its net movement in the present epoch is one of moving closer – radial velocity (speed away from our star system) is −12 km/s.[6]
This is an aging red giant star with a stellar classification of M3 III,[3] indicating it has exhausted the hydrogen at its core and evolved off the main sequence. It is a candidate long-period variable star[5] and has been given the designation YY Psc.[12] It varies in brightness between magnitudes 4.31 and 4.41 with no clear period. Possible periods of 23.1, 32.0, 53.6, and 167.8 days have been identified.[11] The star has 109 times the Sun's radius and is radiating 1,600 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,490 K.[7]
