WR 12

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WR 12
V378VelLightCurve.png
A visual band light curve for V378 Velorum, plotted from ASAS-SN data [1]
Observation data
Epoch J2000       Equinox J2000
Constellation Vela
Right ascension 08h 44m 47.290s [2]
Declination −45° 58′ 55.42″ [2]
Apparent magnitude  (V)10.78 [3]
Characteristics
Spectral type WN8h [4]
U−B color index –0.39 [3]
B−V color index +0.56 [3]
Variable type Algol + WR [5]
Astrometry
Proper motion (μ)RA: −2.979 [2]   mas/yr
Dec.: +3.777 [2]   mas/yr
Parallax (π)0.1756 ± 0.0129  mas [2]
Distance 19,000 ± 1,000  ly
(5,700 ± 400  pc)
Absolute magnitude  (MV)−6.68 [4] (−6.5 + −5.5 [6] )
Orbit [7]
Period (P)23.92336±0.00001  d
Eccentricity (e)0
Inclination (i)78.8 [6] °
Periastron epoch (T)2,449,811.188±0.065
Semi-amplitude (K1)
(primary)		141.9±2.2 km/s
Details [4]
WR
Mass 30  M☉
Radius 16.38  R☉
Luminosity (bolometric)851,000 [8]   L☉
Temperature 44,700  K
Other designations
WR  12, V378  Velorum, CD−45°4482, 2MASS  J08444729-4558554, Hen 3-200
Database references
SIMBAD data

WR 12 (V378 Velorum) 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.

The spectrum of WR 12 is dominated by the broad emission lines of the primary Wolf-Rayet star. The lowest ionisation nitrogen emission lines are strongest, with NV lines being very weak. The HeI lines are stronger than the HeII lines. Unusually the hydrogen emission is stronger still, leading to a WN8h spectral class. CIV emission is almost undetectable. [9] It has been suggested that the companion is a class O star, but its lines cannot be seen in the spectrum. [6]

The system produces eclipses which dim the brightness of the star by 0.12 magnitudes every 24 days. The stars are detached and so it is classified as an Algol-type eclipsing binary. The inclination of the orbit has been estimated at 78.8° but a full orbital solution is not available because the secondary cannot be directly detected. [5] [6]

Related Research Articles

<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 46</span> Star in the constellation Crux

WR 46 is a Wolf-Rayet star in the constellation of the Southern Cross of apparent magnitude +10.8. It is located at 55 arcmin north of Theta2 Crucis. The star is a member of the distant stellar association Cru OB4, and is around 2,900 parsecs or 9,300 light years from the Solar System.

<span class="mw-page-title-main">WR 25</span> Binary star system in the constellation Carina

WR 25 is a binary star system in the turbulent star-forming region the Carina Nebula, about 6,800 light-years from Earth. It contains a Wolf-Rayet star and a hot luminous companion and is a member of the Trumpler 16 cluster. The name comes from the Catalogue of Galactic Wolf–Rayet Stars.

<span class="mw-page-title-main">WR 24</span> Wolf-Rayet star in the constellation Carina

WR 24 is a Wolf-Rayet star in the constellation Carina. It is one of the most luminous stars known. At the edge of naked eye visibility it is also one of the brightest Wolf Rayet stars in the sky.

<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.

<span class="mw-page-title-main">WR 20a</span> Star in the constellation Carina

WR 20a is an eclipsing binary star belonging to or recently ejected from the young, massive cluster Westerlund 2. It was discovered in 2004 to be one of the most massive binary systems known, for which the masses of the components have been accurately measured.

<span class="mw-page-title-main">CD Crucis</span> Eclipsing binary star system in the constellation Crux

CD Crucis, also known as HD 311884, is an eclipsing binary star system in the constellation Crux. It is around 14,000 light years away near the faint open cluster Hogg 15. The binary contains a Wolf–Rayet star and is also known as WR 47.

<span class="mw-page-title-main">WR 31a</span> Wolf Rayet star in the constellation Carina

WR 31a, commonly referred to as Hen 3-519, is a Wolf–Rayet (WR) star in the southern constellation of Carina that is surrounded by an expanding Wolf–Rayet nebula. It is not a classical old stripped-envelope WR star, but a young massive star which still has some hydrogen left in its atmosphere.

<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.

<span class="mw-page-title-main">WR 137</span> Star in the constellation of Cygnus

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

<span class="mw-page-title-main">WR 1</span> Star in the constellation Cassiopeia

WR 1 is a Wolf-Rayet star located around 10,300 light years away from Earth in the constellation of Cassiopeia. It is only slightly more than twice the size of the sun, but due to a temperature over 100,000 K it is over 758,000 times as luminous as the sun.

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 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.

<span class="mw-page-title-main">WR 133</span> Wolf-Rayet star and spectroscopic binary star in the constellation of Cygnus

WR 133 is a visually moderately bright Wolf-Rayet star. It is a spectroscopic binary system containing a Wolf-Rayet primary and a class O supergiant secondary. It is in the constellation of Cygnus, lying in the sky at the centre of the triangle formed by β and γ Cygni, near η Cygni. It is the brightest member of the sparse open cluster NGC 6871.

<span class="mw-page-title-main">WR 120</span> Binary star system in the constellation Scutum

WR 120 is a binary containing two Wolf-Rayet stars in the constellation of Scutum, around 10,000 light years away. The primary is a hydrogen-free weak-lined WN7 star, the secondary is a hydrogen-free WN3 or 4 star, and the system is a possible member of the cluster Dolidze 33. From our point of view, WR 120 is reddened by 4.82 magnitudes, and it has the variable designation of V462 Scuti.

<span class="mw-page-title-main">CV Serpentis</span>

CV Serpentis is a binary star system in the equatorial constellation of Serpens. It is a detached eclipsing binary with an orbital period of 29.7 days. The system includes a Wolf–Rayet (WR) star with the identifier WR 113. The system is located at a distance of approximately 6,700 light years from the Sun based on parallax measurements. It is a member of the Serpens OB2 association of co-moving stars.

References

  1. ↑ "ASAS-SN Variable Stars Database". ASAS-SN Variable Stars Database. ASAS-SN. Retrieved 6 January 2022.
  2. 1 2 3 4 5 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. 1 2 3 Moffat, A. F. J.; Vogt, N. (1975). "Southern open star clusters IV. UBV-Hbeta photometry of 26 clusters from Monoceros to Vela". Astronomy and Astrophysics. 20: 85. Bibcode:1975A&AS...20...85M.
  4. 1 2 3 Sota, 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. arXiv: 1904.04687 . Bibcode:2019A&A...625A..57H. doi:10.1051/0004-6361/201834850. S2CID   104292503.
  5. 1 2 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 Lamontagne, Robert; Moffat, Anthony F. J.; Drissen, Laurent; Robert, Carmelle; Matthews, Jaymie M. (1996). "Photometric Determination of Orbital Inclinations and Mass Loss Rates for Wolf-Rayet Stars in WR+O Binaries". Astronomical Journal. 112: 2227. Bibcode:1996AJ....112.2227L. doi: 10.1086/118175 .
  7. ↑ Fahed, R.; Moffat, A. F. J. (2012). "Colliding winds in five WR+O systems of the Southern hemisphere". Monthly Notices of the Royal Astronomical Society. 424 (3): 1601. Bibcode:2012MNRAS.424.1601F. doi: 10.1111/j.1365-2966.2012.20494.x .
  8. ↑ Crowther, Paul A.; Rate, Gemma (2020). "Unlocking Galactic Wolf–Rayet stars with Gaia DR2 – I. Distances and absolute magnitudes". Monthly Notices of the Royal Astronomical Society. 493 (1): 1512–1529. arXiv: 1912.10125 . Bibcode:2020MNRAS.493.1512R. doi:10.1093/mnras/stz3614. S2CID   209444955.
  9. ↑ Smith, Lindsey F.; Shara, Michael M.; Moffat, Anthony F. J. (1996). "A three-dimensional classification for WN stars". Monthly Notices of the Royal Astronomical Society. 281 (1): 163–191. Bibcode:1996MNRAS.281..163S. doi: 10.1093/mnras/281.1.163 .
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