Talk:R Doradus

From Wikipedia, the free encyclopedia

	Astronomy Portal This article is within the scope of WikiProject Astronomy, which collaborates on articles related to astronomy, and WikiProject Astronomical Objects, which collaborates on articles related to astronomical objects.
Stub	This article has been rated as Stub-Class on the assessment scale.
Help with this template This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.

This article has been automatically assessed as Stub-Class by WikiProject Astronomy because it uses a stub template. If you agree with the assessment, please remove {{WPAstronomy}}'s auto=yes parameter from this talk page. If you disagree with the assessment, please change it by editing the class parameter of the {{WPAstronomy}} template, removing {{WPAstronomy}}'s auto=yes parameter from this talk page, and removing the stub template from the article.

[edit] One solar mass?!?

The article says this star has a mass approximately equal to that of the sun. I don't believe this -- after all, it's a giant star, while our sun isn't. RobertAustin 15:55, 7 January 2007 (UTC)

Nevermind. Some additional research convinced me that the article is, in fact, correct. RobertAustin 16:13, 7 January 2007 (UTC)

But some explanation might be in order. I won't put it in the article because I'm relying on my own general knowledge rather than sources I can cite. The article says it's a red giant. That means it's in its death throes. The thermonuclear reactions change because the composition has changed. The new reactions are faster and hotter, and the outer parts of the star swell tremendously. Note this irony. The surface temperature will be a lot cooler; a red star is significantly cooler than a yellow one. The total energy output will be several zeroes greater. But it will be distributed over a hugely greater surface area. The sun will reach that stage--I believe it's projected in about 10 billion years. I've heard variously that Mercury and maybe Venus will be swallowed up and the oceans and atmosphere on Earth will be boiled away, or that Earth would be swallowed up, too. 140.147.160.78 19:44, 16 January 2007 (UTC)Stephen Kosciesza

[edit] The diameter of R Doradus in kilometers

Note how the press release of Note 1 contain inconsistent data for the diameter: "The measured size implies that it has a physical diameter of 370 +- 50 times that of the Sun, or well over 250 million km!". The diameter of the sun is 1.392 million km. 370 times that is 515 million kilometers, not "well over 250 million km" (ok, very well over). The source of the press release can be found at [1] and gives the size only as 370 +- 50 times that of the Sun. Shirifan 22:40, 27 March 2007 (UTC)

It's just confusing radius and diameter. Half of 515 million is 257.5 million. That's 370 Suns either way. Sagittarian Milky Way 09:52, 5 April 2007 (UTC)