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Feb
5
answered Galaxy rotation curve and dark matter
Feb
5
comment Galaxy rotation curve and dark matter
Can you substantiate your claim (that galaxy rotation curves are calculated from what you call the shell theorem)? For near-spherical object, the error one makes with this assumption is very small (at most a few %).
Feb
5
answered Why are gas giants colored the way they are?
Feb
5
answered Why are all quasars so far away?
Jan
26
comment How do stars or galaxies get their spin?
@HugoRune I edited the question somewhat, but yes, it is somewhat similar to the Brownian motion, except that the expectation value is much larger. Don't forget that the ISM is not smooth, but has structure on many scales (while a gas has only the molecular structure and is smooth on larger scales up to macroscopic scales, when there may be structure again).
Jan
26
revised How do stars or galaxies get their spin?
added 123 characters in body
Jan
25
answered How do stars or galaxies get their spin?
Dec
18
awarded  Yearling
Dec
12
answered Why are stars so far apart?
Dec
12
comment What is the most oblate astronomical object known?
The question is still ill-posed. Strictly speaking, there are no oblate spheroids. Oblate spheroid is a concept and real objects can only ever approximate such a concept. The question then is how well does the object have to satisfy this concept? There may be a pretty flat asteroid which happens to be near oblate (but not flattened by rotation, of course -- that was not required in the question).
Dec
11
comment What is the most oblate astronomical object known?
I think your question is ill-posed, as it uses the concepts of polar and equatorial diameter. However, for an irregular object these are not well-defined.
Dec
11
answered What is the most oblate astronomical object known?
Dec
11
comment What is the most oblate astronomical object known?
Well, that's not what you've asked (originally). Perhaps you should qualify your answer then. IHMO, my suggestions are not trick answers, but honest and correct answers to your original question.
Dec
9
comment What is the most oblate astronomical object known?
What's an object? Would Saturn's rings qualify? -- they are pretty flat. Otherwise, what about the Galactic disc? or other astrophysical discs (accretion discs have aspect ratios 1:1000)? None of these are fully self-gravitating: there is always a round component contributing or even dominating gravity...
Dec
7
answered How to convert a gravitational force to speed and direction
Dec
4
awarded  Custodian
Dec
4
reviewed Leave Open How can there be anything “beyond” the CMB?
Dec
4
answered Could discoid galaxies be expanding?
Dec
3
comment Why does the distance between Sun and Earth stay the same?
@StanLiou Do you have a www reference for that?
Dec
3
comment Why does the distance between Sun and Earth stay the same?
Being pushed some way doesn't imply that you're necessarily falling that way. See also the update to my answer.