WR 134

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WR 134

Observation data
Epoch 2000      Equinox 2000
Constellation Cygnus
Right ascension 20h 11m 14.193s
Declination 36° 10′ 35.07″
Apparent magnitude (V) 8.02
Characteristics
Evolutionary stage Wolf-Rayet
Spectral type WN6-s[1]
U−B color index -0.63
B−V color index 0.20
Variable type Algol
Astrometry
Proper motion (μ) RA: -4.66 mas/yr
Dec.: -8.59 mas/yr
Parallax (π) 0.04 ± 0.68 mas
Distance 1,740[2] pc
Absolute magnitude (MV) -5.07[1]
Details
Mass 19[1] M
Radius 5.29[1] R
Luminosity 400,000[1] L
Temperature 63,100[1] K
Other designations
V1769 Cygni, HD 191765, WR 134, HIP 99377, SAO 69541
Database references
SIMBAD data

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,[3] 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.[4] Rustamov suggests a 1.887 day orbital period with a K-M dwarf companion, but with additional optical variations.[5]

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.[6]

References[edit]

  1. ^ 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/0608078. Bibcode:2006A&A...457.1015H. doi:10.1051/0004-6361:20065052.  edit
  2. ^ Van Der Hucht, K. A. (2001). "The VIIth catalogue of galactic Wolf–Rayet stars". New Astronomy Reviews 45 (3): 135. doi:10.1016/S1387-6473(00)00112-3.  edit
  3. ^ Bibcode1971GCVS3.C......0K
  4. ^ 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. doi:10.1086/307250.  edit
  5. ^ 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. doi:10.1134/S1063772912100058.  edit
  6. ^ 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. doi:10.1088/0004-6256/139/3/825.  edit

External links[edit]

http://apod.nasa.gov/apod/ap120621.html