WR 137

Last updated
WR 137
Observation data
Epoch J2000       Equinox J2000
Constellation Cygnus
Right ascension 20h 14m 31.76669s [1]
Declination 36° 39′ 39.5982″ [1]
Apparent magnitude  (V)7.91 [2] (7.86 - 7.93 [3] )
Characteristics
Evolutionary stage Wolf-Rayet
Spectral type WC7pd + O9V [4]
U−B color index −0.40 [2]
B−V color index +0.29 [2]
Variable type WR [5]
Astrometry
Proper motion (μ)RA: −2.681 [1]   mas/yr
Dec.: −5.739 [1]   mas/yr
Parallax (π)0.4898 ± 0.0172  mas [1]
Distance 6,700 ± 200  ly
(2,040 ± 70  pc)
Absolute magnitude  (MV)−5.7 [6] (−4.18 + −4.34) [4]
Orbit [6]
Period (P)4,766 ± 66
Semi-major axis (a)16 AU
Eccentricity (e)0.178 ± 0.042
Inclination (i)67°
Semi-amplitude (K1)
(primary)		27.9 ± 1.2 km/s
Semi-amplitude (K2)
(secondary)		6.1 ± 1.3 km/s
Details
WR
Mass 4.4 ± 1.5 [6]   M☉
Radius 3.8 ± 1 [4]   R☉
Luminosity 398,000 [7]   L☉
Temperature 60,000 ± 5,000 [4]   K
O
Mass 20 ± 2 [6]   M☉
Radius 7.7 ± 1 [4]   R☉
Luminosity158,000 [7]   L☉
Surface gravity (log g)4.0 ± 0.3 [4]   cgs
Temperature 32,000 ± 2,000 [4]   K
Rotational velocity (v sin i)220 ± 20 [4]  km/s
Age 4.1 [7]   Myr
Other designations
V1679  Cygni, WR  137, HD  192641, HIP  99769, BD+35°4001, Hen 3-1839
Database references
SIMBAD data
Spectrum of WR 137 showing the prominent emission lines of ionised Carbon and Helium Wr137 spc.png
Spectrum of WR 137 showing the prominent emission lines of ionised Carbon and Helium

WR 137 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus.

WR 137, together with WR 134 and WR 135, 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. [8] It is a member of the carbon sequence of WR stars, indicated by the lack of nitrogen lines and the strength of carbon emission. WR 137 has a spectrum with CIII emission weaker than CIV and OV weaker still, leading to the assignment of a WC7 spectral type. The spectrum also shows emission lines of HeII and OIV. [9] [10]

A blue band light curve for V1679 Cygni, plotted from data published by Panov et al. (2000) V1679CygLightCurve.png
A blue band light curve for V1679 Cygni, plotted from data published by Panov et al. (2000)

WR 137 is a binary system, with an O9 main sequence or giant companion. The two stars orbit every thirteen years in a mildly eccentric orbit, and there is an episode of dust production near periastron. The inclination of the orbit is uncertain, most likely near 67° but with some analyses suggesting values around 23°. [6] The O star is visually brighter and more massive, but the WR star dominates the spectrum and has a higher bolometric luminosity. Visible in the spectrum are absorption lines and some narrow emission lines, each thought to originate from the secondary star. The line profiles suggest a decretion disc around the star, produced by its rapid rotation, which would make it the only known system containing a WR star and an Oe star. [7]

WR 137 is about 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. [12] Its properties are uncertain because of the presence of the hot luminous companion. A pseudo-fit of the combined spectrum yielded a temperature of 56,000 K, a luminosity of 537,000 L☉, and a radius of 10 R☉. A more typical radius for a WC7 star would be 4.5 R☉, implying a hotter temperature. [6]

Evolutionary modelling of the WR 137 pair suggest an initial mass for the primary of 60 M☉ and for the secondary of 30 M☉, with an age of 4.1 million years. The initial orbital period would have been around 1,580 days. Around three M☉ have been transferred from the primary to the secondary. [7]

Related Research Articles

<span class="mw-page-title-main">Wolf–Rayet star</span> Heterogeneous class of stars with unusual spectra

Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds. The surface temperatures of known Wolf–Rayet stars range from 20,000 K to around 210,000 K, hotter than almost all other kinds of stars. They were previously called W-type stars referring to their spectral classification.

<span class="mw-page-title-main">WR 136</span> Star in the constellation of Cygnus

WR 136 is a Wolf–Rayet star located in the constellation Cygnus. It is in the center of the Crescent Nebula. Its age is estimated to be around 4.7 million years and it is nearing the end of its life. Within a few hundred thousand years, it is expected to explode as a supernova.

<span class="mw-page-title-main">WR 22</span> Binary star in the constellation Carina

WR 22, also known as V429 Carinae or HR 4188, is an eclipsing binary star system in the constellation Carina. The system contains a Wolf-Rayet (WR) star that is one of the most massive and most luminous stars known, and is also a bright X-ray source due to colliding winds with a less massive O class companion. Its eclipsing nature and apparent magnitude make it very useful for constraining the properties of luminous hydrogen-rich WR stars.

<span class="mw-page-title-main">WR 148</span> Binary star in the constellation of Cygnus

WR 148 is a spectroscopic binary in the constellation Cygnus. The primary star is a Wolf–Rayet star and one of the most luminous stars known. The secondary has been suspected of being a stellar-mass black hole but may be a class O main sequence star.

<span class="mw-page-title-main">Theta Muscae</span> Star in the constellation Musca

Theta Muscae is a multiple star system in the southern constellation Musca, containing a Wolf-Rayet star and two massive companions. With an apparent magnitude of 5.5, it is the second-brightest Wolf–Rayet star in the sky, although much of the visual brightness comes from the massive companions and it is not one of the closest of its type.

<span class="mw-page-title-main">WR 134</span> Star in the constellation of Cygnus

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. 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 142 is a Wolf-Rayet star in the constellation Cygnus, an extremely rare star on the WO oxygen sequence. It is a luminous and very hot star, highly evolved and close to exploding as a supernova. It is suspected to be a binary star with a companion orbiting about 1 AU away.

<span class="mw-page-title-main">WR 102</span> Star in the constellation Sagittarius

WR 102 is a Wolf–Rayet star in the constellation Sagittarius, an extremely rare star on the WO oxygen sequence. It is a luminous and very hot star, highly evolved and close to exploding as a supernova.

WR 114 is a Wolf-Rayet star in the constellation of Scutum. It is an early type star of the carbon sequence (WCE) classified as WC5.

<span class="mw-page-title-main">WR 30a</span> Binary star in the constellation Carina

WR 30a is a massive spectroscopic binary in the constellation Carina. The primary is an extremely rare star on the WO oxygen sequence and the secondary a massive class O star. It appears near the Carina Nebula but is much further away.

WR 135 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. It is just over four times the radius of the sun, but due to a temperature of 63,000 K it is 250,000 times as luminous as the sun.

WR 111 is a Wolf-Rayet (WR) star in the constellation Sagittarius. It is magnitude 7.8 and lies about 5,150 light-years away. It is one of the brightest and most closely studied WR stars.

<span class="mw-page-title-main">WR 86</span>

WR 86 is a visual binary in the constellation Scorpius consisting of a Wolf-Rayet star and a β Cephei variable. It lies 2° west of NGC 6357 on the edge of the Great Rift in the Milky Way in the tail of the Scorpion.

<span class="mw-page-title-main">WR 140</span> Star in the constellation of Cygnus

WR 140 is a visually moderately bright Wolf-Rayet star placed within the spectroscopic binary star, SBC9 1232, whose primary star is an evolved spectral class O4-5 star. It is located in the constellation of Cygnus, lying in the sky at the centre of the triangle formed by Deneb, γ Cygni and δ Cygni.

WR 2 is a Wolf-Rayet star located around 8,000 light years away from Earth in the constellation of Cassiopeia, in the stellar association Cassiopeia OB1. It is smaller than the Sun, but due to a temperature over 140,000 K it is 282,000 times as luminous as the Sun. With a radius of 89% that of the Sun, it is the smallest known WN star in the Milky Way.

WR 3 is a Wolf-Rayet star located around 9,500 light years away from Earth in the constellation of Cassiopeia.

<span class="mw-page-title-main">WR 12</span> Star in the constellation Vela

WR 12 is a spectroscopic binary in the constellation Vela. It is an eclipsing binary consisting of a Wolf-Rayet star and a luminous companion of unknown spectral type. The primary is one of the most luminous stars known.

<span class="mw-page-title-main">WR 9</span> Spectroscopic binary star system in the constellation Puppis

WR 9 is a spectroscopic binary in the constellation Puppis consisting of a Wolf-Rayet star and a class O star. It is around 12,000 light years away.

<span class="mw-page-title-main">HD 151932</span> Star in the constellation of Scorpius

HD 151932, also known as WR 78, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 1,300 parsecs away from the Earth. Despite being a blue-colored Wolf-Rayet star, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands. HD 151932 lies about 22′ west of the open cluster NGC 6231, the center of the OB association Scorpius OB1; it is not clear whether it is a part of the association or not. With an apparent magnitude of about 6.5, it is one of the few Wolf-Rayet stars that can be seen with the naked eye.

WR 150 is a Wolf-Rayet star in the constellation of Cygnus. It is one of the early-type carbon sequence (WCE), and is of spectral type WC5. WR 150 is very far from the Earth, being 28,500 light-years from it.

References

  1. 1 2 3 4 5 Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics . 649: A1. arXiv: 2012.01533 . Bibcode:2021A&A...649A...1G. doi: 10.1051/0004-6361/202039657 . S2CID   227254300. (Erratum:  doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  2. 1 2 3 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. ↑ Alfonso-Garzón, J.; Domingo, A.; Mas-Hesse, J. M.; Giménez, A. (2012). "The first INTEGRAL-OMC catalogue of optically variable sources". Astronomy & Astrophysics. 548: A79. arXiv: 1210.0821 . Bibcode:2012A&A...548A..79A. doi:10.1051/0004-6361/201220095. S2CID   118428054.
  4. 1 2 3 4 5 6 7 8 Richardson, Noel D.; Shenar, Tomer; Roy-Loubier, Olivier; Schaefer, Gail; Moffat, Anthony F. J.; St-Louis, Nicole; Gies, Douglas R.; Farrington, Chris; Hill, Grant M.; Williams, Peredur M.; Gordon, Kathryn; Pablo, Herbert; Ramiaramanantsoa, Tahina (2016). "The CHARA Array resolves the long-period Wolf–Rayet binaries WR 137 and WR 138". Monthly Notices of the Royal Astronomical Society. 461 (4): 4115–4124. arXiv: 1606.09586 . Bibcode:2016MNRAS.461.4115R. doi:10.1093/mnras/stw1585. S2CID   35333968.
  5. ↑ 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.
  6. 1 2 3 4 5 6 Lefèvre, L.; Marchenko, S. V.; Lépine, S.; Moffat, A. F. J.; Acker, A.; Harries, T. J.; Annuk, K.; Bohlender, D. A.; Demers, H.; Grosdidier, Y.; Hill, G. M.; Morrison, N. D.; Knauth, D. C.; Skalkowski, G.; Viti, S. (2005). "Spectroscopic study of the long-period dust-producing WC7pd+O9 binary HD192641". Monthly Notices of the Royal Astronomical Society. 360 (1): 141–152. arXiv: astro-ph/0504475 . Bibcode:2005MNRAS.360..141L. doi:10.1111/j.1365-2966.2005.09017.x. S2CID   14511057.
  7. 1 2 3 4 5 St-Louis, N.; Piaulet, C.; Richardson, N. D.; Shenar, T.; Moffat, A F J.; Eversberg, T.; Hill, G. M.; Gauza, B.; Knapen, J. H.; Kubát, J.; Kubátová, B.; Sablowski, D. P.; Simón-Díaz, S.; Bolduan, F.; Dias, F. M.; Dubreuil, P.; Fuchs, D.; Garrel, T.; Grutzeck, G.; Hunger, T.; Küsters, D.; Langenbrink, M.; Leadbeater, R.; Li, D.; Lopez, A.; Mauclaire, B.; Moldenhawer, T.; Potter, M.; Dos Santos, E. M.; et al. (2020). "An extensive spectroscopic time series of three Wolf–Rayet stars – II. A search for wind asymmetries in the dust-forming WC7 binary WR137". Monthly Notices of the Royal Astronomical Society. 497 (4): 4448–4458. arXiv: 2007.09239 . Bibcode:2020MNRAS.497.4448S. doi:10.1093/mnras/staa2214. S2CID   220646604.
  8. ↑ Murdin, P. (2001). "Wolf, Charles J E (1827-1918)". The Encyclopedia of Astronomy and Astrophysics. p. 4101. Bibcode:2000eaa..bookE4101.. doi:10.1888/0333750888/4101. ISBN   0333750888.
  9. ↑ Hiltner, W. A.; Schild, R. E. (1966). "Spectral Classification of Wolf-Rayet Stars". Astrophysical Journal. 143: 770. Bibcode:1966ApJ...143..770H. doi:10.1086/148556.
  10. ↑ Sander, A.; Hamann, W.-R.; Todt, H. (2012). "The Galactic WC stars. Stellar parameters from spectral analyses indicate a new evolutionary sequence". Astronomy & Astrophysics. 540: A144. arXiv: 1201.6354 . Bibcode:2012A&A...540A.144S. doi:10.1051/0004-6361/201117830. S2CID   119182468.
  11. ↑ Panov, Kiril P.; Altmann, Martin; Seggewiss, Wilhelm (March 2000). "Long-term photometry of the Wolf-Rayet stars WR 137, WR 140, WR 148, and WR 153". Astronomy and Astrophysics. 355: 607–616. arXiv: astro-ph/0002221 . Bibcode:2000A&A...355..607P . Retrieved 29 December 2021.
  12. ↑ Gervais, Simon; St-Louis, Nicole (1999). "A Large H I Shell surrounding the Wolf-Rayet Star HD 191765". The Astronomical Journal. 118 (5): 2394. Bibcode:1999AJ....118.2394G. doi: 10.1086/301065 .
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