T Persei
Star in the constellation Perseus
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T Persei is a red supergiant located in the constellation Perseus. It varies in brightness between magnitudes 8.3 and 9.7 and is considered to be a member of the Double Cluster.
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Perseus |
| Right ascension | 02h 19m 21.87717s[2] |
| Declination | +58° 57′ 40.3455″[2] |
| Apparent magnitude (V) | 8.34-9.70[3] |
| Characteristics | |
| Spectral type | M2Iab[4] |
| U−B color index | +2.62[5] |
| B−V color index | +2.33[5] |
| Variable type | SRc[3] |
| Astrometry | |
| Radial velocity (Rv) | −40.85[6] km/s |
| Proper motion (μ) | RA: −1.237[2] mas/yr Dec.: −0.186[2] mas/yr |
| Parallax (π) | 0.4119±0.0237 mas[2] |
| Distance | 2345±55[7] pc |
| Absolute magnitude (MV) | −6.90±0.07[7] |
| Details[7] | |
| Mass | 9-12 M☉ |
| Radius | 510±20 R☉ |
| Luminosity | 45,700+4,400 −4,000 L☉ |
| Surface gravity (log g) | 0.06±0.05 cgs |
| Temperature | 3,750±60 K |
| Metallicity [Fe/H] | −0.35 dex |
| Other designations | |
| T Per, HD 14142, HIP 10829, BD+58°439, WDS J02194+5858, 2MASS J02192186+5857403, AAVSO 0212+58 | |
| Database references | |
| SIMBAD | data |
T Persei is a member of the Perseus OB1 association around the h and χ Persei open clusters, around 2 degrees north of the centre of the clusters. It is generally treated as an outlying member of the clusters.[8] It lies half a degree away from S Persei, another red supergiant Double Cluster member.
Vojtěch Šafařík discovered that the star is a variable star in 1882.[9] It was listed with its variable star designation, T Persei, in Annie Jump Cannon's 1907 work Second Catalog of Variable Stars.[10] T Per is a semiregular variable star, whose brightness varies from magnitude 8.34 to 9.7 over a period of 2,430 days.[3] Unlike many red supergiants, it does not appear to have a long secondary period.[4][11] It is relatively inactive for the red supergiant star, with low mass loss rate 8×10−6 Solar_mass/year and no detectable dust shell.[12]
The Washington Double Star Catalog lists T Persei as having a 9th magnitude companion 0.1 arc-seconds away. This is derived from Hipparcos measurements. However, no other sources report a companion.[13]