Talk:Contact binary

split?
Should this be split and disambiguated? Trevor 01:33, 11 March 2006 (UTC)


 * Common envelope binary is just waiting to be turned into a real article 132.205.44.134 00:31, 21 September 2006 (UTC)

Statement of age of contact binary of months or years - Is this for short period binaries only?
The statement "the latter describes a dynamically unstable phase in binary evolution which either expels the stellar envelope or merges the binary in a timescale of months to years" has no citation to back it up.

I think it must refer to the suggested "short period cutoff" for close together binary contact stars. Also the theory that stars in contact with each other with very short periods should merge within a year or two is being challenged by observations of stable contact binary stars with faster periods than the theory predicts:

http://www.researchgate.net/profile/Eduardo_Fernandez-Lajus/publication/273177494_SDSS_J001641-000925_THE_FIRST_STABLE_RED_DWARF_CONTACT_BINARY_WITH_A_CLOSE-IN_STELLAR_COMPANION/links/5500643b0cf2d61f820d6f4d.pdf

I'll add a citation needed tag to it for now. If the author is watching this - can you clarify - what type of star? Is it referring to the short period cutoff or something else? Robert Walker (talk) 00:25, 17 October 2015 (UTC)


 * I am not the author but I believe this statement is referring to common envelope systems, not the short period cut-off for contact binary systems. I have added a citation to the most recent review article on common envelope evolution. -- Quarticle (talk) 15:12, 17 October 2015 (UTC)


 * Oh I see, I had read it back to front without noticing. I hope you don't mind, I've rewritten that last sentence, removing the words "former" and "latter" which can be confusing occasionally to some readers like myself. I have wondered sometimes if I have mild dislexia because of things like this. Anyway it all makes sense now. Robert Walker (talk) 17:08, 17 October 2015 (UTC)

Speed of rotation of binaries in this configuration
I don't know this subject at all, but it would seem to me that two stars who are so close as to be in physical contact with each other, yet still have a lifetime measured in millions or billions of years, would have to have an extraordinarily fast rotation rate around each other - but I have no idea what yardstock/revolution speed we are talking about. Does anybody who knows this subject have any idea? I mean, do they revolve in weeks, days, hours, minutes, seconds? Thanks in advance to anybody who knows.