Talk:Supernova remnant

Removed[edit]

I removed this sentence:

Because of this evolved supernova remnants are used for high-Mach number shock physics.^[1]

This statement is misleading. It associates high-Mach shocks with evolved remnants, whereas young remnants have much higher Machs - and are better observed. The article given as reference is not about high-Mach shocks at all. It only mentions this aspect in the first sentences of the introduction. And it does not say that old supernova remnants are used to study high-Mach shocks. It says that it was believed thatold remnantswere better suited forstudies of high Mach shocksand of shock/ISM interaction and of the ISM itselfthan for studies of supernova explosions and nucleosynthesis, however recent observations have proved they can do the latter too. So that was citation abuse. --130.179.72.179 (talk) 01:20, 22 October 2011 (UTC)[reply]

^ Katsuda, Satoru; Hwang, Una; Petre, Robert; Park, Sangwook; Mori, Koji; Tsunemi, Hiroshi. "DISCOVERY OF X-RAY-EMITTING O-Ne-Mg-RICH EJECTA IN THE GALACTIC SUPERNOVA REMNANT PUPPIS A". The Astrophysics Journal. IOP Science. Retrieved 10 October 2011.{{cite web}}: CS1 maint: multiple names: authors list (link)

Miscellany[edit]

From the article: "A few other well-known, older, supernova remnants are the Crab Nebula, a remnant of a relatively recent explosion (AD 1054); Tycho (SN 1572), a remnant named after Tycho Brahe, who recorded the brightness of its original explosion (AD 1572)"

Assuming those dates reflect when the light from these supernovae were first visible on Earth, shouldn't the dates for the explosions be more like n-d=n`where n is the date listed and d is the distance (in light years) from Earth to the site of the supernova? Azmo23

In fact, when we are referring to a supernova event, we are talking about an event that occurred on the earth (a new star observed by humans in the sky), not about the explosion itself (which, you are right, happened much before that date). There is the same kind of confusion when we say that the Crab remnant is about 1000 years old: we actually want to say that we observe it (today) as it was 1000 years after the explosion (we can't know how it looks right now). --130.179.72.179 (talk) 22:42, 13 May 2011 (UTC)[reply]

Actually, the proper English is either, "it ceases" or "it may cease," likewise "it undergoes" or "it may undergo". We need to either change it back or eliminate the "may". :) -- April

I slipped on the "cease" i changed it back. However, i don't agree with the other. I don't see the "may" of "may accumulate" affecting the "reaches" and "undergoes". I might be wrong, but if it has to be changed, both reaches and undergoes must change. AstroNomer

Agreed, that's right. dang, this grammar stuff is tricky. :) -- April

Redo/expand this page[edit]

I'll redo, expand this page when I get a moment, it should really have some stuff on the Sigma-D relation and the Selection effects etc. Could do with links to Molonglo Observatory Synthesis Telescope, Parkes 64m Telescope and Effesberg, since they are the big contributors to finding SNRs (radio sky surveys). Also Dominion Radio Astrophysical Observatory would be good. Am newbie so not sure how to do much yet, but don't mind if anyone jumps in and adds those first. Will write some more sciency stuff on it laters.

If I remember, Sigma-D turned out to basically be an observational effect, not a real diagnostic, much to everyone's disappointment. At any rate, tread very carefully in discussing it, and make sure your background is up to date. Mordecai-Mark Mac Low 00:56, 18 January 2006 (UTC)[reply]

I agree, please review carefully the subject before bloating this article with technical details about a relation that is not even widely accepted in the community. --130.179.72.179 (talk) 22:51, 13 May 2011 (UTC)[reply]

A section is indeed missing on observations: review of emission mechanisms, brief history of discoveries, list of major instruments and techniques, discussion of physical diagnostics... --130.179.72.179 (talk) 22:55, 13 May 2011 (UTC)[reply]

Speed[edit]

How is it that this page says that the material moves at up to 1% the speed of light, where the Supernova page says it moves at up to a tenth the speed of light? Shouldn't they be the same? I don't know which it is, but I'm inclined to think that this one is a typo... Sbrools ^{(talk . contribs)} 18:45, 3 August 2007 (UTC)[reply]

Correct, I fixed that (note that I removed the exact number in km/s, as there is nothing particular about this value "3000"). I also added related info on time and distance scales. --130.179.72.179 (talk) 22:45, 13 May 2011 (UTC)[reply]

G1.9+0.3[edit]

"The youngest known remnant in our galaxy is G1.9+0.3, discovered in the galactic center."

The source defines it as "most recent" supernova in our galaxy, however that's based on earth's time-frame and not the actual age of the remnant (which is actually much, much older). I'd fix it myself, but I'm not equipped at this time to back it up with a clearer reference; any chance that someone happens to have such resources on hand? PrismaticWisp (talk) 00:48, 5 May 2014 (UTC)[reply]

Why no mention of pulsars and soft gamma repeaters[edit]

The first 3 SGRs were found in SNRs and some SN leave behind a pulsar (eg in crab nebula). - Rod57 (talk) 04:33, 8 April 2015 (UTC)[reply]

[1] Katsuda, Satoru; Hwang, Una; Petre, Robert; Park, Sangwook; Mori, Koji; Tsunemi, Hiroshi. "DISCOVERY OF X-RAY-EMITTING O-Ne-Mg-RICH EJECTA IN THE GALACTIC SUPERNOVA REMNANT PUPPIS A". The Astrophysics Journal. IOP Science. Retrieved 10 October 2011.{{cite web}}: CS1 maint: multiple names: authors list (link)

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