WR 134

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WR 134

Observation data
Epoch 2000      Equinox 2000
Constellation Cygnus
Right ascension 20h 11m 14.193s[1]
Declination 36° 10′ 35.07″[1]
Apparent magnitude (V) 8.08[2]
Evolutionary stage Wolf-Rayet
Spectral type WN6-s[3]
U−B color index −0.44[2]
B−V color index 0.00[2]
Variable type Algol[4]
Proper motion (μ) RA: −4.66[1] mas/yr
Dec.: −8.59[1] mas/yr
Parallax (π) 0.04 ± 0.68[1] mas
Distance 1,740[5] pc
Absolute magnitude (MV) -5.07[3]
Mass 19[3] M
Radius 5.29[3] R
Luminosity 400,000[3] L
Temperature 63,100[3] K
Other designations
V1769 Cygni, HD 191765, WR 134, HIP 99377, SAO 69541
Database references

WR 134 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus, surrounded by a faint bubble nebula blown by the intense radiation and fast wind from the star.

WR 134 is classified as an Algol type eclipsing variable and given the designation V1769 Cygni, but the variation is not strictly periodic and brightness changes occur on timescales of hours to days. It has been investigated several times to search for companions. Morel reported a 2.25 day primary period but considered the variations to be due to rotational modulation rather than the effects of a companion.[6] Rustamov suggests a 1.887 day orbital period with a K-M dwarf companion, but with additional optical variations.[7]

Both hard and soft X-rays have been detected from WR 134 but the sources are not fully explained. The emissions do not match a single star of the expected temperature, are not sufficient for colliding winds between two hot stars, and any compact source such as a neutron star or cool dwarf would be in an unlikely orbit.[8]


  1. ^ a b c d e Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653. arXiv:0708.1752free to read. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D. 
  3. ^ a b c d e f Hamann, W. -R.; Gräfener, G.; Liermann, A. (2006). "The Galactic WN stars". Astronomy and Astrophysics. 457 (3): 1015. arXiv:astro-ph/0608078free to read. Bibcode:2006A&A...457.1015H. doi:10.1051/0004-6361:20065052. 
  4. ^ 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. ^ Van Der Hucht, K. A. (2001). "The VIIth catalogue of galactic Wolf–Rayet stars". New Astronomy Reviews. 45 (3): 135. Bibcode:2001NewAR..45..135V. doi:10.1016/S1387-6473(00)00112-3. 
  6. ^ Morel, T.; Marchenko, S. V.; Eenens, P. R. J.; Moffat, A. F. J.; Koenigsberger, G.; Antokhin, I. I.; Eversberg, T.; Tovmassian, G. H.; Hill, G. M.; Cardona, O.; St‐Louis, N. (1999). "A 2.3 Day Periodic Variability in the Apparently Single Wolf‐Rayet Star WR 134: Collapsed Companion or Rotational Modulation?". The Astrophysical Journal. 518: 428. arXiv:astro-ph/9901269free to read. Bibcode:1999ApJ...518..428M. doi:10.1086/307250. 
  7. ^ Rustamov, D. N.; Cherepashchuk, A. M. (2012). "Spectral and photometric studies of the Wolf-Rayet star WR 134 = HD 191765". Astronomy Reports. 56 (10): 761. Bibcode:2012ARep...56..761R. doi:10.1134/S1063772912100058. 
  8. ^ Skinner, S. L.; Zhekov, S. A.; Güdel, M.; Schmutz, W.; Sokal, K. R. (2010). "X-Ray Emission from Nitrogen-Type Wolf-Rayet Stars". The Astronomical Journal. 139 (3): 825. arXiv:0912.1326free to read. Bibcode:2010AJ....139..825S. doi:10.1088/0004-6256/139/3/825. 

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