Wolf–Rayet star

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Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of highly ionised helium and nitrogen or carbon.wikipedia
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R136a1

The naked-eye stars Gamma Velorum and Theta Muscae, as well as the most massive known star, R136a1 in 30 Doradus, are all Wolf–Rayet stars.
RMC 136a1 (usually abbreviated to R136a1) is a Wolf–Rayet star located at the center of R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula.

Helium

Hesuperfluid heliumhelium II
Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of highly ionised helium and nitrogen or carbon.
This series is named for Edward Charles Pickering, who in 1896 published observations of previously unknown lines in the spectrum of the star ζ Puppis (these are now known to occur with Wolf–Rayet and other hot stars).

Gamma Velorum

γ Velorumγ 2 VelGamma² Velorum
The naked-eye stars Gamma Velorum and Theta Muscae, as well as the most massive known star, R136a1 in 30 Doradus, are all Wolf–Rayet stars.
At a combined magnitude +1.7, it is one of the brightest stars in the night sky, and contains by far the closest and brightest Wolf-Rayet star.

Theta Muscae

θ Musθ Muscae
The naked-eye stars Gamma Velorum and Theta Muscae, as well as the most massive known star, R136a1 in 30 Doradus, are all Wolf–Rayet stars.
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.

Luminosity

luminousbolometric luminosityluminosities
All Wolf–Rayet stars are highly luminous objects due to their high temperatures—thousands of times the bolometric luminosity of the Sun for the CSPNe, for the Population I WR stars, to for the WNh stars—although not exceptionally bright visually since most of their radiation output is in the ultraviolet.
In some cases, the process of estimation is extreme, with luminosities being calculated when less than 1% of the energy output is observed, for example with a hot Wolf-Rayet star observed only in the infra-red.

WR 134

In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
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.

WR 137

In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
WR 137 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus.

WR 135

In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
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.

WR 102ka

Peony Star
The seventh catalogue and its annex use the same numbering scheme and insert new stars into the sequence using lower case letter suffixes, for example WR 102ka for one of the numerous WR stars discovered in the galactic centre.
WR 102ka, also known as the Peony star, is a Wolf–Rayet star that is one of several candidates for the most luminous-known star in the Milky Way.

WR 42e

This applies to all discoveries since the 2006 annex, although some of these have already been named under the previous nomenclature; thus WR 42e is now numbered WR 42-1.
WR 42e (2MASS J11144550-115001) is a Wolf-Rayet star in the massive H II region NGC 3603 in the constellation of the Carina.

WR 25

It contains a Wolf-Rayet star and a hot luminous companion, and is a member of the Trumpler 16 cluster.

AB7

In the Small Magellanic Cloud SMC WR numbers are used, usually referred to as AB numbers, for example AB7.
A Wolf-Rayet star and a supergiant companion of spectral type O orbit in a period of 19.56 days.

Cygnus (constellation)

Cygnusconstellation of CygnusCygnus constellation
In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
Cygnus X-3 is a microquasar containing a Wolf–Rayet star in orbit around a very compact object, with a period of only 4.8 hours.

Charles Wolf (astronomer)

Charles WolfWolf
In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
In 1867 he and Georges Rayet discovered Wolf–Rayet stars.

WR 46

WR 46 (DI Crucis) is a Wolf-Rayet star in the constellation of the Southern Cross of apparent magnitude +10.8.

Henry Draper Catalogue

HDHD cataloguecatalog
The first three Wolf Rayet stars to be identified, coincidentally all with hot O companions, had already been numbered in the HD catalogue.
The classification scheme used was to subdivide the previously used Secchi classes (I to IV) into more specific classes, given letters from A to N. Also, the letter O was used for stars whose spectra consisted mainly of bright lines, the letter P for planetary nebulae, and the letter Q for spectra not fitting into any of the classes A through P. No star of type N appeared in the catalogue, and the only star of type O was the Wolf–Rayet star HR 2583.

WR 1

WR 1 is a Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cassiopeia.

WR 2

WR 2 is a Wolf-Rayet star located around 8,000 light years away from Earth in the constellation of Cassiopeia.

WR 124

WR 124 is a Wolf–Rayet star in the constellation of Sagitta surrounded by a ring nebula of expelled material known as M1-67.

WR 142

WR 142 is a Wolf-Rayet star in the constellation Cygnus, an extremely rare star on the WO oxygen sequence.

WR 104

Peter Tuthill
Usually this takes place on those belonging to binary systems as a product of the collision of the stellar winds forming the pair, as is the case of the famous binary WR 104; however this process occurs on single ones too.
The primary star is a Wolf-Rayet star, abbreviated as WR, with a B0.5 main sequence star in close orbit and another more distant fainter companion.

Starburst galaxy

starburst galaxiesstarburststarbursts
WR stars are expected to be particularly common in starburst galaxies and especially Wolf–Rayet galaxies.
*Wolf-Rayet galaxies (WR galaxies), galaxies where a large portion of the bright stars are Wolf-Rayet stars.

Asymptotic giant branch

AGBpost-AGBasymptotic-giant-branch
A separate group of stars with WR spectra are the central stars of planetary nebulae (CSPNe), post asymptotic giant branch stars that were similar to the Sun while on the main sequence, but have now ceased fusion and shed their atmospheres to reveal a bare carbon-oxygen core.
Observationally, this late thermal pulse phase appears almost identical to a Wolf–Rayet star in the midst of its own planetary nebula.

Georges Rayet

Georges Antoine Pons RayetRayet
In 1867, using the 40 cm Foucault telescope at the Paris Observatory, astronomers Charles Wolf and Georges Rayet discovered three stars in the constellation Cygnus (HD 191765, HD 192103 and HD 192641, now designated as WR 134, WR 135, and WR 137 respectively) that displayed broad emission bands on an otherwise continuous spectrum.
He discovered Wolf–Rayet stars together with Charles Wolf in 1867.

WR 102ea