X Persei

From Wikipedia, the free encyclopedia
Jump to: navigation, search
X Persei
Perseus constellation map.svg
Red circle.svg

Location of X Per (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Perseus
Right ascension 03h 55m 23.07715s[1]
Declination +31° 02′ 450062″[1]
Apparent magnitude (V) 6.778[2] (6.03 - 7.00[3])
Spectral type O9.5IIIe-B0Ve[4]
U−B color index −0.790[2]
B−V color index +0.137[2]
Variable type γ Cas + X-ray pulsar[3]
Radial velocity (Rv) −50.00[5] km/s
Proper motion (μ) RA: −2.28[1] mas/yr
Dec.: −5.42[1] mas/yr
Parallax (π) 2.34 ± 0.70[1] mas
Distance 950[6] pc
Absolute magnitude (MV) −3.47[2]
Primary X Per
Companion 4U 0352+309
Period (P) 250.3 days
Semi-major axis (a) 2.2 AU
Eccentricity (e) 0.111
Inclination (i) 23 - 30°
Mass 15.5[8] M
Radius 6.5[8] R
Luminosity 29,000[2] L
Surface gravity (log g) 4.0[2] cgs
Temperature 29,500[8] K
Rotational velocity (v sin i) 215[2] km/s
Age 5[2] Myr
Other designations
X Persei, HR 1209, HIP 18350, HD 24534, BD+30°591, WDS J03554+3103, AAVSO 0349+30
A: X Per
B: 4U 0352+309
Database references

X Persei is a binary star system located in the constellation Perseus, approximately 950 parsecs away.

The optical star X Persei has been classified either as an O-type giant or a B-type main sequence star. It is a Be star, rotating rapidly, and at times surrounded by a disk of expelled material. This qualifies it as a Gamma Cassiopeia variable, and the visual range is magnitude 6 - 7. There is a faint optical companion separated by 22.5" which the Catalog of Components of Double and Multiple Stars refers to as X Persei B.[9]

X Persei A is in orbit with a neutron star, which is catalogued as 4U 0352+309 in the final Uhuru catalog of X-ray objects. It is a pulsar with an unusually long period of 837 seconds.[7]


  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752Freely accessible. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d e f g h Lyubimkov, L. S.; Rostopchin, S. I.; Roche, P.; Tarasov, A. E. (1997). "Fundamental parameters, helium abundance and distance of X Persei". Monthly Notices of the Royal Astronomical Society. 286 (3): 549. Bibcode:1997MNRAS.286..549L. doi:10.1093/mnras/286.3.549. 
  3. ^ 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. 
  4. ^ Valencic, Lynne A.; Smith, Randall K. (2013). "Interstellar Abundances toward X Per, Revisited". The Astrophysical Journal. 770: 22. Bibcode:2013ApJ...770...22V. doi:10.1088/0004-637X/770/1/22. 
  5. ^ Kharchenko, N. V.; Scholz, R.-D.; Piskunov, A. E.; Röser, S.; Schilbach, E. (2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ˜55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889. arXiv:0705.0878Freely accessible. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. 
  6. ^ Walter, Roland; Lutovinov, Alexander A.; Bozzo, Enrico; Tsygankov, Sergey S. (2015). "High-mass X-ray binaries in the Milky Way. A closer look with INTEGRAL". The Astronomy and Astrophysics Review. 23: 2. arXiv:1505.03651Freely accessible. Bibcode:2015A&ARv..23....2W. doi:10.1007/s00159-015-0082-6. 
  7. ^ a b Delgado‐Marti, H.; Levine, A. M.; Pfahl, E.; Rappaport, S. A. (2001). "The Orbit of X Persei and Its Neutron Star Companion". The Astrophysical Journal. 546: 455. arXiv:astro-ph/0004258Freely accessible. Bibcode:2001ApJ...546..455D. doi:10.1086/318236. 
  8. ^ a b c Grundstrom, E. D.; Boyajian, T. S.; Finch, C.; Gies, D. R.; Huang, W.; McSwain, M. V.; O'Brien, D. P.; Riddle, R. L.; Trippe, M. L.; Williams, S. J.; Wingert, D. W.; Zaballa, R. A. (2007). "Joint Hα and X-Ray Observations of Massive X-Ray Binaries. III. The Be X-Ray Binaries HDE 245770 = A0535+26 and X Persei". The Astrophysical Journal. 660 (2): 1398. arXiv:astro-ph/0702283Freely accessible. Bibcode:2007ApJ...660.1398G. doi:10.1086/514325. 
  9. ^ Dommanget, J.; Nys, O. (1994). "Catalogue des composantes d'etoiles doubles et multiples (CCDM) premiere edition - Catalogue of the components of double and multiple stars (CCDM) first edition". Com. de l'Observ. Royal de Belgique. 115: 1. Bibcode:1994CoORB.115....1D.