Talk:Wolf–Rayet star

Orphan question, no date...

So, according to the article, would a wolf-rayet star have to be in a binary system with either powerful solar wind or a location very close to its companion?

No, this was just some confusion on the part of whoever originally wrote this. Although it was thought in the 1960's that perhaps all Wolf-Rayet stars were formed as part of binary evolution (in which the material from the pre-WR star was removed through the gravity of the companion), it was demonstrated long ago that Wolf-Rayet stars were no more likely to be found in close binary systems than that of any other type of massive star.

Need help from stellar astronomers

I know theories concerning Wolf Rayet stars have been changing rapidly recently. It would be helpful if someone in the field could give a better overview.

==DONE!==6/18/05

I don't know what have been done so clearly but this page is in very very bad shape. The number of errors or misunderstanding is countless. I have been creating most of the Wolf-Rayet wikipedia page on the french website. [1] I'll try to make a reasonable translation soon. Cédric 195.251.173.14 30 June 2005 13:44 (UTC)

I provided a more reasonable text (16 June), but it's disappeared and the original has returned. I've put back a short, but correct, place-holder,

until Cedric can translate his very nice page. ---phil m.

I cleaned up the links section, added proper citations for the links and added a link to Harvard's "catalog of northern Wolf-Rayet Stars and the Central Stars of Planetary Nebulae". ---jamessavik

Editing/Clean-Up

I find this sentence "Furthermore some (roughly 10% of the galactic) central stars of planetary nebulae are - despite of their lower masses - also of the WR-type, i.e. they show emission line spectra with broad lines from helium, carbon and oxygen" fairly difficult to parse. The parenthetical could, at least, be un-parenthesized. Possibly just starting the setence "Furthermore, roughly 10% of galactic central stars..." But I have a feeling that galactic is supposed to be modifying nebulae, not stars. Anyone? Onepairofpants 01:54, 23 March 2006 (UTC)

Fixed wording a couple of weeks ago. Wwheaton (talk) 23:22, 6 March 2008 (UTC)

In the introductory paragraph, the sun is said to be losing some percentage of its mass each year due to solar wind, but in comparison, "a Wolf-Rayet star loses 10−5% solar masses a year." Either it's a percentage (in which case "solar masses" should go) or it's an absolute mass loss measured in solar masses (in which case the percentage should go). 192.31.106.35 (talk) 17:41, 18 January 2008 (UTC)btiemann

WO (oxygen) types are not explained

Stellar classification has the WO class labelled. Unfortunately, I am unfamilar with this class. Thanks, CarpD 3/5/07

Slightly clarified, I hope correctly, in the description section. The WO stars are grouped with the WC stars, but show more oxygen lines. I believe (but have not put in the article) that these are stars that have progressed through the CNO H-burning stage, and expelled their H envelopes (which shows us the N-rich products of CNO burning), then started burning He by the triple-alpha process, making lots of C; and then processed enough C & N to O to show that in their surface layers and winds. Someone who knows more may want to correct me on this, I'm guessing. Wwheaton (talk) 23:22, 6 March 2008 (UTC)

A nice introductory page on WRs

I don't have time to work on this now, but [2] has a lot of info at a fairly introductory level, looks good. Modest Genius ^talk 00:07, 13 March 2007 (UTC)

Mass loss?

While our own sun loses 10^-14 of its own mass on a yearly basis, a Wolf-Rayet star loses 10^-5 solar masses a year. - is the 10^-5 with respect to the solar mass of the sun or with respect to the mass of the WR star? The second would make WR stars extremely short-lived, of course. --Stephan Schulz 13:34, 25 April 2007 (UTC)

A solar mass is the mass of the Sun, so yes it's losing the mass of the Sun every 100,000 years: 20 × the Sun every 2 million years (assuming a constant rate). That's also very short-lived on the cosmic time scale. — RJH (talk) 21:48, 6 September 2007 (UTC)

Number known

More like about 590 in MW, as far as I can count from in 2007 version of Skiff's star spectral catalogue of 2007 (Oct), when removing duplicates and foreign galaxy WR:s. Said: Rursus ☻ 14:12, 11 January 2008 (UTC)

I see van der Hucht (2001), cited by Crowther (2007), listed only 225 in the Galaxy, but that is significantly older. Wwheaton (talk) 22:59, 19 February 2008 (UTC)

Expanded description section

Based on Crowther's 2007 review, I have enlarged the description section to include more on the evolutionary status of these stars. Not being an expert on the subject, review and (likely) correction by others working in the field would be appreciated. Wwheaton (talk) 22:51, 19 February 2008 (UTC)

Is WR104 a death star?

How's that for a sensationalistic section header? :)

Perhaps someone better qualified than I can evaluate whether the star described in this article merits a mention in this page:

"University of Sydney astronomer Peter Tuthill discovered an elegant rotating pinwheel system known as WR104 in the constellation Sagittarius eight years ago. ... It contains a Wolf-Rayet star, the last stop in a star's life before it explodes in a massive supernova. .. While studying WR104's striking and colorful shape, Dr Tuthill noticed that the perfect spiral he was observing could only occur when staring right down the centre of it." Death star may pose threat to planet Earth

Sounds kind of creepy to me :) --babbage (talk) 10:46, 3 March 2008 (UTC)

Oh, someone started an article about WR 104. Will link to it from here. --babbage (talk) 06:38, 6 March 2008 (UTC)

Changed from stub class?

I hope we have enough information to be beyond stub class by now, so I've tentatively changed the stub indication on this page. (But of course maybe there should be a "Disaster" class, below stub, if there are too many errors?) I also moved the old question on binarity into its own section, to get it below the contents box. No idea how old it may be tho. Wwheaton (talk) 23:22, 6 March 2008 (UTC)

Discrepancy

From article: http://en.wikipedia.org/wiki/Star The Sun loses 10^-14 solar masses every year,

From this talk page While our own sun loses 10^-14 of its own mass on a yearly basis

From this article: While our own sun loses 10^-16 of its own mass every year —Preceding unsigned comment added by Fsjr (talk • contribs) 17:03, 14 July 2008 (UTC)

Roughly 10^-14 is correct for solar wind. Wwheaton (talk) 17:42, 14 July 2008 (UTC)

On that note, the article also says that Wolf-Rayet stars lose 10^-16 Solar Masses each year. That would be less than our own sun. — Preceding unsigned comment added by Limton (talk • contribs) 16:28, 12 February 2012 (UTC)

Wolf Rayet category

Do we need a category for Wolf Rayet stars? There are only two or three currently but I want to add some more. — Preceding unsigned comment added by Lithopsian (talk • contribs) 22:57, 11 June 2012 (UTC)

My mistake, seems like there already is a category. Lithopsian (talk) 22:48, 13 June 2012 (UTC)

Direct collapse to a black hole?

Via an article in Ars Technica, a recent article in Nature (</ref></ref></ref> ) suggests that one of the two black hole mergers seen to date by LIGO may have been caused by direct collapse of Wolf-Rayet stars to black holes, without any supernova explosion.

Well what do you know. I rewrote the Supernova section yesterday and mentioned direct collapse. The Supernova article itself discusses this more. It isn't something specific to WR stars, although the core mass required for it to happen makes it likely that the progenitor would be a WR star. Lithopsian (talk) 20:30, 22 June 2016 (UTC)

References

Some gratuitous feedback

It'd be good to get this to GA or FA. Just some things to think about: Cas Liber (talk · contribs) 20:00, 24 February 2017 (UTC)

• Given we are also writing for lay readers, the article might want to emphasise more in the introduction that they are very hot stars compared with other stars.
• I'd look at everything in Further reading or External links to see if it can be incorporated or culled.
• It is sorta dry. Not sure yet how to liven it up.

Will look more later. gotta run now. Cas Liber (talk · contribs) 20:09, 24 February 2017 (UTC)

Planetary Nebula

In the article is a picture of planetary nebula HD 184738 (Campbell's Star). The caption even says that this is an unrelated phenomenon to WR stars. The nebula in question is not even mentioned in the article. The nebula doesn't have a Wikipedia article of it's own. Does the picture need to be on a page about WR stars or on a page about planetary nebulas?162.40.51.136 (talk) 23:52, 24 January 2018 (UTC)

The caption doesn't say it is unrelated to WR stars. Read the article. Then change the caption to express the concept in a way you feel is more clear ;) Lithopsian (talk) 13:23, 25 January 2018 (UTC)

Temperature mix-up???

In the table "Physical properties of galactic population I WO/C stars", L(·) of WO2 is 460000; for WC4, it is 130000. How is WC4 brighter than WO2? Thy Pyrometer (talk) 04:47, 13 June 2021 (UTC)

Why wouldn't it be? Does the data in the article match the reference? What exactly is it that you think is wrong? Lithopsian (talk) 13:38, 13 June 2021 (UTC)