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#1
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HELP! - simple question!
what DEATHS of celestial objects have humans witnessed without a
telescope? (not including meteors)? with the dates if possible. thanx |
#2
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Hi Look up 'crab nebula china' in google gaz |
#3
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lucky, err, vomit wrote:
what DEATHS of celestial objects have humans witnessed without a telescope? (not including meteors)? with the dates if possible. *Without* a telescope? That means not even Shoemaker-Levy 9 is in play, so you're probably limited to supernovae in our galaxy. So, Kepler's in 1604, Tycho's in 1572, another one in Cassiopeia in 1181, the Crab in 1054, Lupus in 1006, and two more reported by the Chinese in 393 and 183, in Scorpius and Centaurus, respectively. If we include supernovae in the telescopic era that were observed without a telescope, you can add on at least the 1987 supernova in the Large Magellanic Cloud. I don't know of any other supernovae that were definitely visible (as such) to the unaided eye since Kepler's supernovae, although to be sure, S Andromedae in 1885 must have been close to visible, if not actually visible. Brian Tung The Astronomy Corner at http://astro.isi.edu/ Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/ The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/ My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt |
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Zane wrote:
Brian, please tell me you had to look some of that up. The thought that you had all that in fast memory is too depressing. Heh. I remember 1604, 1572, 1054, and 1006, but yes--I had to look the rest of them up. Fortunately, I've posted about these supernovae before, so I only had to Google my previous post. Of course, 1987 is, I assume, in reasonably fresh memory for most folks here. (Please don't anyone post a reply just to tell us all that you weren't born yet in 1987.) Brian Tung The Astronomy Corner at http://astro.isi.edu/ Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/ The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/ My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt |
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Chris L Peterson wrote:
Not to mention an additional supernova every few centuries going back many thousands of years, until the observers might reasonably no longer be considered "human". None of these are precisely dated, of course, although I'm sure that estimates can be made in some cases where we can observe planetary nebulas. Sure. There's the Gum Nebula, for one. That must have been some supernova! All of this depends on whether a supernova actually constitutes a "death" in the sense the OP had in mind. I prefer to think of them as transforming events. Certainly, the progenitor star continues its existence, albeit in a quite different form. I think it can certainly be said that Type Ia supernovae are death events. And if a star is considered to be a fusor, then the other supernovae are also death events. Death, after all, is not end of existence. I too will exist after I die (unless I'm atomized). I just won't be alive. Brian Tung The Astronomy Corner at http://astro.isi.edu/ Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/ The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/ My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt |
#7
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On Fri, 22 Apr 2005 18:44:10 +0000 (UTC), (Brian Tung)
wrote: Death, after all, is not end of existence. I too will exist after I die (unless I'm atomized). I just won't be alive. Well, yes, but then a star was never alive in the first place, so this does very much depend on how "death" is used. Even in the case of a type 1a supernova, you are left with an active object in the same location as the original pair of objects, and containing lots of the original material. Death? I don't know. Anyway, it really just word games we are playing here. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
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Chris L Peterson wrote:
Well, yes, but then a star was never alive in the first place, so this does very much depend on how "death" is used. Even in the case of a type 1a supernova, you are left with an active object in the same location as the original pair of objects, and containing lots of the original material. Death? I don't know. Anyway, it really just word games we are playing here. A star is commonly considered to be a fusor, isn't it? After the supernova, it ceases to be a fusor. As a star, it dies. It's just a lump of warm whatever after that, slowly cooling--just like a dead human being. I thought a Type Ia supernova commonly resulted in the complete detonation of the progenitor star--I thought it was the Type II supernovae that leaves a black hole, or neutron star, or whatever. The Type Ia's partner might leave around some stuff, but I wouldn't consider that to be part of the original star. Brian Tung The Astronomy Corner at http://astro.isi.edu/ Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/ The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/ My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt |
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On Fri, 22 Apr 2005 21:24:14 +0000 (UTC), (Brian Tung)
wrote: A star is commonly considered to be a fusor, isn't it? After the supernova, it ceases to be a fusor. As a star, it dies. It's just a lump of warm whatever after that, slowly cooling--just like a dead human being. Not an unreasonable definition of stellar death. I thought a Type Ia supernova commonly resulted in the complete detonation of the progenitor star--I thought it was the Type II supernovae that leaves a black hole, or neutron star, or whatever. The Type Ia's partner might leave around some stuff, but I wouldn't consider that to be part of the original star. I thought all supernovas leave one or two compact objects behind, but a little research seems to suggest that type Ia events probably result in the complete dispersal of the progenitor neutron star. I guess that qualifies as "death" just about any way you look at it! _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
#10
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