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Astronomy Picture of the Day -- Cataclysmic Dawn [art]
NASA ^ | January 11, 2015 | (see photo credit)

Posted on 01/11/2015 11:49:40 AM PST by SunkenCiv

Explanation: Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star. Explosive cataclysmic events such as a dwarf nova can occur when a clump of gas in the interior of the accretion disk heats up past a certain temperature. At that point, the clump will fall more quickly onto the white dwarf and land with a bright flash. Such dwarf novas will not destroy either star, and may occur irregularly on time scales from a few days to tens of years. Although a nova is much less energetic than a supernova, if recurrent novas are not violent enough to expel more gas than is falling in, mass will accumulate onto the white dwarf star until it passes its Chandrasekhar limit. At that point, a foreground cave may provide little protection, as the entire white dwarf star will explode in a tremendous supernova.

January 11, 2015

(Excerpt) Read more at 129.164.179.22 ...


TOPICS: Astronomy; Astronomy Picture of the Day; Science
KEYWORDS: apod; astronomy; science
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[ Illustration Credit & Copyright: Mark A. Garlick (Space-art.co.uk)]

1 posted on 01/11/2015 11:49:40 AM PST by SunkenCiv
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Astronomy Picture of the Day Archive - A -
2 posted on 01/11/2015 11:51:47 AM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: brytlea; cripplecreek; decimon; bigheadfred; KoRn; Grammy; steelyourfaith; Mmogamer; dayglored; ...
I hadn't thought about this artist in a long time -- his old website is still alive and well, since there was no larger image available, the link goes to his eponymous website instead.

3 posted on 01/11/2015 11:51:57 AM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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[foul language] I just noticed the links are no good, so I'll have to fix those and repost the first two installments. Mea culpa.

4 posted on 01/11/2015 11:56:39 AM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: SunkenCiv
Still able to generate some good ones with space engine.


5 posted on 01/11/2015 12:34:32 PM PST by cripplecreek (You can't half ass conservatism.)
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To: SunkenCiv
is it possible according the laws of physics to have two bodies the the size of the moons depicted in the painting that close together???

or would one of them be pulled into the other?

6 posted on 01/11/2015 12:40:33 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: Chode
is it possible according the laws of physics to have two bodies the the size of the moons depicted in the painting that close together???

Yes. Even suns can be quite close together.


7 posted on 01/11/2015 1:31:05 PM PST by fso301
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To: fso301
damn, i forgot about that, i guess that settles it then... 8^)
8 posted on 01/11/2015 1:53:41 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: Chode
It all depends on mass and speed. The bigger the mass, the faster the speed and they won't crash into each other.

Multiple Star Systems
9 posted on 01/11/2015 3:23:40 PM PST by Svartalfiar
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To: Chode

Also, one body could be X times larger, yet X times farther away yielding the same angular size, like the Sun & Moon at eclipse.

It is a neat artist’s rendition, but I think the lighting on the crescents is off…


10 posted on 01/11/2015 3:41:50 PM PST by mikrofon (APOD Bump)
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To: Svartalfiar
the two body problem is interesting
11 posted on 01/11/2015 4:11:10 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: mikrofon
true, but my question still stands if all things are equal

as to the shadows, i don't know how that would work with only one light source

12 posted on 01/11/2015 4:17:41 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: Chode
...question still stands if all things are equal...

It's called the Roche limit.

13 posted on 01/11/2015 4:35:27 PM PST by Nateman (If liberals are not screaming you are doing it wrong!)
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To: Nateman
thank you...
14 posted on 01/11/2015 4:38:49 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: Chode
The Roche limit applies to stars as well. During the cold war satellites designed to detect the gamma rays from nuclear explosions started to detect flashes of gamma ray light not from the Earth. They were so brief these “Gamma Ray Busters” were a real puzzle , even pin pointing where they happened was a real problem. Eventually satellites were made to hunt them down and some understanding of what is happening occurred. I mention this because one of the theories is that some of these busters are from neutron stars in tight orbit. The orbits get closer as energy radiates away in gravity waves. They eventually reach a Roche limit and this is what happens.
15 posted on 01/11/2015 4:55:25 PM PST by Nateman (If liberals are not screaming you are doing it wrong!)
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To: Nateman
whoa
16 posted on 01/11/2015 5:06:45 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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To: cripplecreek

Pretty nice! Too wide here, but looks great!


17 posted on 01/11/2015 5:20:01 PM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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CORRECTED:
Astronomy Picture of the Day Archive - A -
18 posted on 01/11/2015 5:25:45 PM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: Chode

They wouldn’t have facing crescents, for one thing. They could be on the same side, with one much further out but larger, and the planet would be in orbit around it, with the smaller, nearer body in orbit around the planet.


19 posted on 01/11/2015 6:04:07 PM PST by SunkenCiv (Imagine an imaginary menagerie manager imagining managing an imaginary menagerie.)
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To: SunkenCiv
i'd think it would require two light sources no matter what
20 posted on 01/11/2015 6:41:32 PM PST by Chode (Stand UP and Be Counted, or line up and be numbered - *DTOM* -w- NO Pity for the LAZY - 86-44)
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