Related Research Articles
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.
S Doradus is one of the brightest stars in the Large Magellanic Cloud (LMC), a satellite galaxy of the Milky Way, located roughly 160,000 light-years away. The star is a luminous blue variable, and one of the most luminous stars known, having a luminosity varying widely above and below 1,000,000 times the luminosity of the Sun, although it is too far away to be seen with the naked eye.
NGC 3603 is a nebula situated in the Carina–Sagittarius Arm of the Milky Way around 20,000 light-years away from the Solar System. It is a massive H II region containing a very compact open cluster HD 97950.
Westerlund 2 is an obscured compact young star cluster in the Milky Way, with an estimated age of about one or two million years. It contains some of the hottest, brightest, and most massive stars known. The cluster resides inside a stellar breeding ground known as Gum 29, located 20,000 light-years away in the constellation Carina. It is half a degree from the naked eye Cepheid variable V399 Carinae.
NGC 3603-A1 is a double-eclipsing binary star system located at the centre of the HD 97950 cluster in the NGC 3603 star-forming region, about 25,000 light years from Earth. Both stars are of spectral type WN6h and among the most luminous and most massive known.
HD 5980 is a multiple star system on the outskirts of NGC 346 in the Small Magellanic Cloud (SMC) and is one of the brightest stars in the SMC.
AB7, also known as SMC WR7, is a binary star in the Small Magellanic Cloud. A Wolf–Rayet star and a supergiant companion of spectral type O orbit in a period of 19.56 days. The system is surrounded by a ring-shaped nebula known as a bubble nebula.
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.
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.
NGC 3603-B is a Wolf-Rayet star located at the centre of the HD 97950 cluster in the NGC 3603 star-forming region, about 25,000 light years from Earth. It has the spectral type WN6h and is among the most luminous and most massive stars known.
NGC 3603-C is a single-lined spectroscopic binary star system located at the centre of the HD 97950 cluster in the NGC 3603 star-forming region, about 25,000 light years from Earth. The primary has spectral type WN6h and is among the most luminous and most massive known.
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.
WR 42e is a Wolf–Rayet star in the massive H II region NGC 3603 in the constellation of the Carina. It is around 25,000 light-years or 7,600 parsec from the Sun. WR 42e is one of the most massive and most luminous stars known.
LMC195-1 is a Wolf–Rayet star located in the Large Magellanic Cloud (LMC). It is an extremely rare member of the WO oxygen sequence, at WO2 the hottest known in the LMC. It is likely to be one of the hottest stars known.
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.
AB8, also known as SMC WR8, is a binary star in the Small Magellanic Cloud (SMC). A Wolf-Rayet star and a main sequence companion of spectral type O orbit in a period of 16.638 days. It is one of only nine known WO stars, the only Wolf-Rayet star in the SMC not on the nitrogen sequence, and the only Wolf-Rayet star in the SMC outside the main bar.
LH 41-1042 is a Wolf–Rayet star located in the Large Magellanic Cloud (LMC). It is an extremely rare member of the WO oxygen sequence, the second to be discovered in the LMC and one of only three found so far in that galaxy.
Romano's Star is a luminous blue variable star located in the Messier 33 galaxy in the constellation of Triangulum.
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.
HD 326823, also known as V1104 Scorpii, is a binary star containing a unique emission-line star, which is in the midst of transitioning to a nitrogen-rich Wolf-Rayet star, as well as being a candidate Luminous blue variable, located 4,142 light years away in the constellation of Scorpius. The primary is very evolved, because it is composed of almost entirely helium, and only 3% of it is still hydrogen, and it has lost most of its mass to the now-very-massive secondary. The underlying mechanisms and mass transfers in the system are comparable to other W Serpentis systems, such as Beta Lyrae and RY Scuti.
References
- 1 2 3 4 Massey, Philip; McNeill, Reagin T.; Olsen, K. A. G.; Hodge, Paul W.; Blaha, Cynthia; Jacoby, George H.; Smith, R. C.; Strong, Shay B. (2007-12-01). "A Survey of Local Group Galaxies Currently Forming Stars. III. A Search for Luminous Blue Variables and Other Hα Emission-Line Stars". The Astronomical Journal. 134 (6): 2474–2503. arXiv: 0709.1267 . Bibcode:2007AJ....134.2474M. doi:10.1086/523658. ISSN 0004-6256. S2CID 119255465.
- ↑ Massey, Philip; Olsen, K. A. G.; Hodge, Paul W.; Jacoby, George H.; McNeill, Reagin T.; Smith, R. C.; Strong, Shay B. (2007). "A Survey of Local Group Galaxies Currently Forming Stars. II. UBVRI Photometry of Stars in Seven Dwarfs and a Comparison of the Entire Sample". The Astronomical Journal. 133 (5): 2393–2417. arXiv: astro-ph/0702236 . Bibcode:2007AJ....133.2393M. doi:10.1086/513319. S2CID 119456878.
- 1 2 3 4 5 6 7 8 Abbott, Jay Brian (2004-01-01). Quantitative spectroscopic studies of Wolf-Rayet stars in local group galaxies (Thesis). Bibcode:2004PhDT.......161A.
- 1 2 Dimitrova, Tzvetelina A.; Neugent, Kathryn F.; Massey, Philip; Levesque, Emily M. (2022-02-01). "Locating Red Supergiants in the Galaxy NGC 6822". The Astronomical Journal. 163 (2): 70. arXiv: 2112.03990 . Bibcode:2022AJ....163...70D. doi: 10.3847/1538-3881/ac410e . ISSN 0004-6256. S2CID 244954507.
- 1 2 Westerlund, B. E.; Azzopardi, M.; Breysacher, J.; Lequeux, J. (1983-07-01). "Discovery of a Wolf-Rayet star in NGC 6822". Astronomy and Astrophysics. 123: 159–161. Bibcode:1983A&A...123..159W. ISSN 0004-6361.
- 1 2 Neugent, Kathryn; Massey, Philip (2019-08-01). "The Wolf-Rayet Content of the Galaxies of the Local Group and Beyond". Galaxies. 7 (3): 74. arXiv: 1908.06238 . Bibcode:2019Galax...7...74N. doi: 10.3390/galaxies7030074 .
- ↑ Armandroff, T. E.; Massey, P. (1985-04-01). "Wolf-Rayet stars in NGC 6822 and IC 1613". The Astrophysical Journal. 291: 685–692. Bibcode:1985ApJ...291..685A. doi: 10.1086/163107 . ISSN 0004-637X.
- ↑ Massey, Philip; Conti, Peter S.; Armandroff, Taft E. (1987-12-01). "The Spectra of Extra-Galactic Wolf-Rayet Stars". The Astronomical Journal. 94: 1538. Bibcode:1987AJ.....94.1538M. doi:10.1086/114586. ISSN 0004-6256.