WR 134 is a
variableWolf-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. It is five times the radius of the sun, but due to a temperature over 63,000
K it is 400,000 times as
luminous as the Sun.
WR 134 was one of three stars in
Cygnus observed in 1867 to have unusual spectra consisting of intense
emission lines rather than the more normal continuum and
absorption lines. These were the first members of the class of stars that came to be called Wolf-Rayet stars (WR stars) after
Charles Wolf and
Georges Rayet who discovered their unusual appearance.[7] It is a member of the nitrogen sequence of WR stars, while the other two (
WR 135 and
WR 137) are both members of the carbon sequence that also have
OB companions. WR 134 has a spectrum with NIII and NIV emission between two and five times stronger than NV, leading to the assignment of a WN6 spectral type. The
spectrum also shows strong HeII emission and weaker lines of HeI and CIV.[8]
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.[10] Rustamov suggests a 1.887 day orbital period with a K-M dwarf companion, but with additional optical variations.[11]
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.[12]
WR 134 is less than a degree away from WR 135 and the two are believed to lie at approximately the same distance from Earth within the Cygnus OB3 association.[13] Both stars lie within a shell of hydrogen thought to have been swept up from the
interstellar medium when one or both stars were on the
main sequence. The shell is over forty parsecs wide and contains about 1,830
M☉ of hydrogen. It is unclear which of the two stars is primarily responsible for creating the shell.[14]
^
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abcdefSota, A.; Maíz Apellániz, J.; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J.; Oskinova, L. M. (2019). "The Galactic WN stars revisited. Impact of Gaia distances on fundamental stellar parameters". Astronomy & Astrophysics. A57: 625.
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^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.
^Marchenko, S. V.; Moffat, A. F. J.; van der Hucht, K. A.; Seggewiss, W.; Schrijver, H.; Stenholm, B.; Lundström, I.; Setia Gunawan, D. Y. A.; Sutantyo, W.; van den Heuvel, E. P. J.; De Cuyper, J. P.; Gómez, A. E. (March 1998).
"Wolf-Rayet stars and O-star runaways with HIPPARCOS II. Photometry". Astronomy and Astrophysics. 331: 1022–1036.
Bibcode:
1998A&A...331.1022M. Retrieved 29 December 2021.
^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 (1): 428–441.
arXiv:astro-ph/9901269.
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1999ApJ...518..428M.
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10.1086/307250.
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