XX Persei


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.

XX Persei
Comet Lovejoy.jpg
Red circle.svg
XX Persei (circled) near the Double Cluster and Comet Lovejoy
Credit: Juan lacruz
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]
Spectral type M4Ib + B7V[3]
Variable type SRc[4]
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]
Distance2,029[6] pc
Absolute magnitude (MV)−4.6[7]
Mass16[7] M
Radius548[8] - 681[6] R
Luminosity42,000[8] L
Temperature3,535±170[8] K
Other designations
XX Per, BD+54°444, GSC 03689-01837, HD 12401, HIP 9582, IRC+50052, 2MASS J02030935+5513566, HV 3414, SAO 22875, AAVSO 0156+54
Database references


A visual band light curve for XX Persei, plotted from ASAS-SN data[9]

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]

See alsoEdit


  1. ^ a b Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. S2CID 18759600.
  2. ^ a b Kiss, L. L.; Szabó, Gy. M.; Bedding, T. R. (2006). "Variability in red supergiant stars: Pulsations, long secondary periods and convection noise". Monthly Notices of the Royal Astronomical Society. 372 (4): 1721–1734. arXiv:astro-ph/0608438. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x. S2CID 5203133.
  3. ^ a b c Proust, D.; Ochsenbein, F.; Pettersen, B. R. (1981). "A catalogue of variable-visual binary stars". Astronomy and Astrophysics Supplement Series. 44: 179. Bibcode:1981A&AS...44..179P.
  4. ^ a b Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  5. ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  6. ^ a b Norris, Ryan P. (2019). Seeing Stars Like Never Before: A Long-term Interferometric Imaging Survey of Red Supergiants (PDF) (PhD). Georgia State University.
  7. ^ a b c d Stothers, R.; Leung, K. C. (1971). "Luminosities, masses and periodicities of massive red supergiants". Astronomy and Astrophysics. 10: 290. Bibcode:1971A&A....10..290S.
  8. ^ a b c Messineo, M.; Brown, A. G. A. (2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal. 158 (1): 20. arXiv:1905.03744. Bibcode:2019AJ....158...20M. doi:10.3847/1538-3881/ab1cbd. S2CID 148571616.
  9. ^ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
  10. ^ Percy, John R.; Sato, Hiromitsu (2009). "Long Secondary Periods in Pulsating Red Supergiant Stars". Journal of the Royal Astronomical Society of Canada. 103 (1): 11. Bibcode:2009JRASC.103...11P.
  11. ^ Reiter, Megan; Marengo, Massimo; Hora, Joseph L.; Fazio, Giovanni G. (2015). "A Spitzer/IRAC characterization of Galactic AGB and RSG stars". Monthly Notices of the Royal Astronomical Society. 447 (4): 3909. arXiv:1501.02749. Bibcode:2015MNRAS.447.3909R. doi:10.1093/mnras/stu2725. S2CID 118515353.
  12. ^ Fok, Thomas K. T.; Nakashima, Jun-Ichi; Yung, Bosco H. K.; Hsia, Chih-Hao; Deguchi, Shuji (2012). "Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters". The Astrophysical Journal. 760 (1): 65. arXiv:1209.6427. Bibcode:2012ApJ...760...65F. doi:10.1088/0004-637X/760/1/65. S2CID 53393926.
  13. ^ Verheyen, L.; Messineo, M.; Menten, K. M. (2012). "SiO maser emission from red supergiants across the Galaxy . I. Targets in massive star clusters". Astronomy & Astrophysics. 541: A36. arXiv:1203.4727. Bibcode:2012A&A...541A..36V. doi:10.1051/0004-6361/201118265. S2CID 55630819.
  14. ^ Buss, Richard H.; Snow, Theodore P. (1988). "Hot components and circumstellar grains in M supergiant syncretic binaries". Astrophysical Journal. 335: 331. Bibcode:1988ApJ...335..331B. doi:10.1086/166931.