XX Persei (IRC +50052 / HIP 9582 / BD+54 444) is a semiregular variable red supergiant star in the constellation Perseus, between the Double Cluster and the border with Andromeda.
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Perseus |
Right ascension | 02h 03m 09.36064s[1] |
Declination | 55° 13′ 56.6187″[1] |
Apparent magnitude (V) | 7.9 - 9.0[2] |
Characteristics | |
Spectral type | M4Ib + B7V[3] |
Variable type | SRc[4] |
Astrometry | |
Proper motion (μ) | RA: -1.232 ± 0.114[5] mas/yr Dec.: -1.543 ± 0.126[5] mas/yr |
Parallax (π) | 0.46 ± 0.07 mas[5] |
Distance | 2,029[6] pc |
Absolute magnitude (MV) | −4.6[7] |
Details | |
Mass | 16[7] M☉ |
Radius | 548[8] - 681[6] R☉ |
Luminosity | 42,000[8] L☉ |
Temperature | 3,535±170[8] K |
Other designations | |
Database references | |
SIMBAD | data |
XX Persei is a semiregular variable star of sub-type SRc, indicating a cool supergiant. The General Catalogue of Variable Stars gives the period as 415 days.[4] It also shows a long secondary period which was originally given at 4,100 days.[7] A more recent study shows only slow variations with a period of 3,150 ± 1,000 days.[2] Another study failed to find any long period up to 10,000 days.[10]
The most likely distance of XX Per is 2,290 parsecs, from assumed membership of the Perseus OB1 association.[11]
XX Per is a red supergiant of spectral type M4Ib with an effective temperature below 4,000 K. It has a large infrared excess, indicating surrounding dust at a temperature of 900 K, but no masers have been detected.[12][13]
XX Persei has a mass of 16 solar masses, above the limit beyond which stars end their lives as supernovae.[7]
XX Persei has a companion of magnitude 9.7 20.5" away.[3] The combined spectral type has been given as M4Ib + B7V,[3] while the UV spectrum of the companion has been used to derive a spectral classification of A.[14]