Talk:Nova
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WikiProject Echo has identified Nova as a foreign language featured article. You may be able to improve this article with information from the Finnish language Wikipedia. |
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[edit] Old talk
Shouldn't "Nova" lead to a disambiguation page first (from the search bar) rather than giving the option of disambiguation from here? Seems cumbersome.--Lazarus Plus 00:55, 16 November 2005 (UTC)
There are three novae listed with magnitudes greater than 7.0. Should those be removed from the table so that the bright novae are only those visible to the naked eye? (mag<6.0) 12.221.81.96 04:50, 26 September 2005 (UTC)
I think that this is distinct from a supernova, actually. From the Supernova article:
"Type Ia: They don't have Helium, and present a line belonging to Silicon. They are generally though to be caused by the explosion of a white dwarf, at or close to the Chandrasekhar limit.
One possibility is that the white dwarf was orbiting a moderately massive star. The dwarf pulls matter from its companion to the point that it reaches the Chandrasekhar limit. The dwarf collapses into a neutron star or black hole, and the collapse causes the remaining carbon and oxygen atoms in it to fuse."
Both involve white dwarfs, but there is a very large difference between the sort of explosion a stellar mass collapsing into a neutron star or black hole would produce and the sort of explosion the mere fusion of a few teratons of hydrogen would produce. Hence the super in supernova.
Don't have time to dig up an actual reference right at this very moment, though.
I'd trust you. :) The thing is, though, the page is not just talking about a nova, but a final explosion which rips the white dwarf apart. As far as I know, this should happen basically when the novating star reaches the Chandrasekhar limit, and so would be identical to a type Ia supernova. Except, thinking about it, for that bit about silicon - a naked core should easily be able to destroy itself with a helium or carbon flash. Hmm. I guess I'll change it back, and leave this as a note that further research is needed.
The distinction is an important one. A nova can occur over and over, as the orbiting white dwarf sucks material from its companion star and ignites it, boom!. A Ia supernova sucks matter from its companion, yes, but the key is that it sucks so much that it goes over the Chandrasekhar limit and BOOM! It's far more energetic, and the majority of the energy comes from a different source (the body of the white dwarf).
If you want a simple rule of thumb, a nova can (and often does) occur multiple times, while a Type Ia supernova -- well, to quote Daffy Duck, "You only get to see this trick once". -- Paul Drye
and believed that it was a "new star." They didn't just believe that it was a new star. It was a new star. It is simply the definition of star has changed. It should read and considered it a new star. Ezra Wax
There appears to be a size consideration dividing "stars likely go through a nova stage" and "stars likely to become supernovae." Can this be included?
[edit] What the ancients believed
The sentence below, pasted from paragraph 3, sentence 2, is irrelevant and distracting from the point of the paragraph.
<The ancients refused to believe that the "fixed stars" could show any changes, and considered these occurrences to be objects close to the earth. >
Thanks, Dave
[edit] Question
Isn't a nova a death of a solar mass star, e.g. our sun will die as a nova? — Hurricane Devon ( Talk ) 22:13, 21 March 2006 (UTC)
- Not according to this article's definition. The sun article says "In about 5 billion years, the Sun will evolve into a red giant and then a white dwarf, creating a planetary nebula in the process." - mako 00:36, 23 March 2006 (UTC)
[edit] interstellar material
The article says:
Spectroscopic observation of nova ejecta nebulae has shown that they are enriched in elements such as helium, carbon, nitrogen, oxygen, neon, and magnesium.[1] Though it would seem that the contributions of novae to the Galaxy might be large over astronomical time scales, this is not the case; in fact, novae supply only 1/50th the amount of material to the interstellar medium as supernovae do, and only 1/200th that of red giant and supergiant stars.
But the red giant and supergiant articles don't mention it at all. Shoundn't they?
Also the article doesn't say what elements are ejected. Is it just H and He, or does any of the He fuse to make heavier elements? --Djfeldman 14:18, 26 July 2006 (UTC)
[edit] Definition
A nova (pl. novae) is a cataclysmic nuclear explosion caused by the accretion of hydrogen onto the surface of a white dwarf star.
Google (define:nova) seems to say that a nova is not the explosion (the event) but rather the star (the object) that explodes.--82.76.37.57 13:53, 4 August 2006 (UTC)
I think nova refers both to the explosion and the visible (or perhaps 'observable') object itself (i.e. the star producing the nova/e). Probably depends on whether you're an astronomer (object) or astrophysicist (explosion). Can anyone confirm? Keramos 14:18, 29 May 2007 (UTC)
[edit] Nova List
The magnitude listed for V1280 Scorpii does not agree with the page for that Nova -- which is it, or is this page talking about something else? -- BillTrost
