Talk:Nova

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)

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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)

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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.

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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

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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?

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

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)

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)

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)

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

About ancient novae, I would like to point out two things.

1. The oracle bone text is NOT from 1400 BC. It is from the late 2nd millennium BC, but we don't know the exact age. And in all probability, it was inscribed after the start of the late Shang dynasty. In that case the earliest possible date is probably somewhere in the interval 1350-1300 BC. Which is well after 1400 BC.

If this object was a nova at all, the problem is then that the object may easily have been a supernova rather than a classical nova.

And if you ask those few people who can read oracle bone texts, you will find that it is not clear how to read this text.

2. Another ancient nova has been missed completely. Z Camelopardalis was recorded by the Chinese in October-November, 77 BC. My reference for this identification is Nature, 2007, July 19, page 251. Taking into account how nearby Z Camelopardalis is situated, the nova would in all probability had been even brighter than V603 Aquilae was in 1918. —Preceding unsigned comment added by 213.113.116.38 (talk) 17:36, 9 June 2009 (UTC)

I'm going to make a separate article of that list. Rursus dixit. (^mbork³!) 10:40, 5 March 2010 (UTC)

Done! Reason: I want to write a little about different kind of novae, and the list was making the article ugly. And WP:BOLD. Rursus dixit. (^mbork³!) 10:59, 5 March 2010 (UTC)

Explosion?

If a nova is an explosion, why does the article skip that little detail? What is a nova like? The article says how it happens, but skips everything after it begins to happen. What actually happens during a nova? —Preceding unsigned comment added by 209.40.210.222 (talk) 22:59, 17 November 2008 (UTC)

Exactly. More information needs to be added about the ACTUAL NOVA PROCESS. --216.165.95.64 (talk) 04:35, 11 May 2009 (UTC)

The article did have section "Development" which described the process; which was blanked in 2008 without anyone noticing (!); and has just now been restored by an alert editor. -84user (talk) 20:59, 10 July 2010 (UTC)

Milky Way vs. Andromeda

Is it really true that more novae are discovered in the Andromeda Galaxy than in the Milky Way (25 vs. 10 per year, according to the article)? I'd expect it would be easier to find them in our own galaxy, if they occur on a similar scale in both galaxies...--Roentgenium111 (talk) 19:03, 4 August 2010 (UTC)

My "guess" would be that the dust lanes of the Milky Way obstruct our view of many local Nova while we have a nice outside view of M31. -- Kheider (talk) 14:30, 11 September 2010 (UTC)

Fast Nova

As of Apr 2010, it seems that the term is still "Fast Nova".[1] -- Kheider (talk) 21:35, 25 September 2010 (UTC)