WR 3

Last updated
WR 3
Observation data
Epoch J2000       Equinox J2000
Constellation Cassiopeia
Right ascension 01h 38m 55.62715s [1]
Declination +58° 09 22.67182 [1]
Apparent magnitude  (V)10.69 [2]
Characteristics
Evolutionary stage Wolf-Rayet
Spectral type WN3-hw [3]
U−B color index −0.86 [2]
B−V color index +0.02 [2]
Astrometry
Radial velocity (Rv)100.00 [4]  km/s
Proper motion (μ)RA: −4.061±0.063 [5]   mas/yr
Dec.: −1.422±0.072 [5]   mas/yr
Parallax (π)0.3131 ± 0.0412  mas [5]
Distance 2,900+520
−390
[6]   pc
Absolute magnitude  (MV)−3.13 [3]
Details
Mass 15 [3]   M
Radius 2.48 [3]   R
Luminosity 363,000 [3]   L
Temperature 89,100 [3]   K
Other designations
HD  9974, WR  3, HIP  7681, 2MASS  J01385562+5809227
Database references
SIMBAD data

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

WR 3 is a member of the nitrogen sequence of WR stars and has a spectrum with strong HeII and NV lines, but weak NIV. HeI lines are very weak or missing, but there are lines of OVI. Unusually, there are lines of hydrogen and absorption components in many lines creating P Cygni profiles. The emission is weaker overall than stars of similar spectral type, and it has often been suggested that WR 3 has a type O binary companion. However, there are no other signs of a companion and it is thought to be a single star with a spectral type of WN3-hw. The "h" and "w" indicate that hydrogen is present and the emission is relatively weak for its class. [7] [8]

Ordered by right ascension, WR 3 was the third star in the Sixth Catalogue of galactic Wolf-Rayet stars. WR 1 and WR 2 are also both early WN stars in Cassiopeiae. [9]

WR 3 is a massive and luminous star. The presence of hydrogen in its spectrum suggests that it is younger than hydrogen-free WR stars and may still be in the process of ejecting the remainder of its hydrogen. The emission lines of heavy elements in its spectrum are produced by strong convection and powerful stellar winds rather than complete loss of the outer layers of the star. [10] The wind has been measured at 2,700 km/s leading to mass being lost at four millionths  M per year. [3]

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">EZ Canis Majoris</span> Binary star system in the constellation Canis Major

EZ Canis Majoris is binary system in the constellation of Canis Major. The primary is a Wolf-Rayet star and it is one of the ten brightest Wolf-Rayet stars, brighter than apparent magnitude 7.

<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.

WR 156 is a young massive and luminous Wolf–Rayet star in the constellation of Cepheus. Although it shows a WR spectrum, it is thought to be a young star still fusing hydrogen in its core.

<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.

<span class="mw-page-title-main">WR 93b</span> Wolf-Rayet star in the constellation of Cygnus

WR 93b is a Wolf-Rayet star in the constellation Scorpius, an extremely rare star on the WO oxygen sequence. It appears near NGC 6357 in the tail of the scorpion.

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.

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 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 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.

<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">WR 128</span> Wolf-Rayet star in the constellation Sagitta

WR 128 is a Wolf–Rayet star located about 9,500 light years away in the constellation of Sagitta. A member of the WN class, WR 128's spectrum resembles that of a WN4 star, but hydrogen is clearly present in the star, making it the only known hydrogen-rich WN4 star in the galaxy. However, similar H-rich very early WN stars can be found in the LMC and especially in the SMC, but the only other galactic examples of this are WR 3 and WR 152.

<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.

References

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  8. Marchenko, S. V.; Moffat, A. F. J.; Crowther, P. A.; Chené, A.-N.; De Serres, M.; Eenens, P. R. J.; Hill, G. M.; Moran, J.; Morel, T. (2004). "Hydrogen in the atmosphere of the evolved WN3 Wolf-Rayet star WR 3: Defying an evolutionary paradigm?" (PDF). Monthly Notices of the Royal Astronomical Society. 353 (1): 153–161. Bibcode:2004MNRAS.353..153M. doi: 10.1111/j.1365-2966.2004.08058.x .
  9. Van Der Hucht, Karel A.; Conti, Peter S.; Lundström, Ingemar; Stenholm, Björn (1981). "The Sixth Catalogue of galactic Wolf-Rayet stars, their past and present". Space Science Reviews. 28 (3): 227–306. Bibcode:1981SSRv...28..227V. doi:10.1007/BF00173260. S2CID   121477300.
  10. Smith, Nathan; Conti, Peter S. (2008). "On the Role of the WNH Phase in the Evolution of Very Massive Stars: Enabling the LBV Instability with Feedback". The Astrophysical Journal. 679 (2): 1467–1477. arXiv: 0802.1742 . Bibcode:2008ApJ...679.1467S. doi:10.1086/586885. S2CID   15529810.