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4 votes

how to make postage stamps of galaxies

Let me see if I can provide a general, conceptual outline of what's going on in making an (individual) postage-stamp image. Decide what input astronomical images you will use. Since the input images ...
Peter Erwin's user avatar
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2 votes

How fast is Andromeda approaching in miles per hour

About 670,000 miles per hour Thanks to blueshifting, we have been able to pin the velocity of the Andromeda Galaxy at about 300 kilometers per SECOND, which when converted, yields a approximate value ...
Furious Arcturus's user avatar
5 votes
Accepted

Spiral Galaxies

You're right that a central mass can't explain the spiral structure (and you're also right about the tangent motion in case the string breaks). Spiral structure is indeed partially caused by gravity, ...
pela's user avatar
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0 votes

Spiral Galaxies

TLDR; Differential Rotation Part 1: Accretion disk Now of course, I am not stating forth that spiral galaxies are the accretion disks of their supermassive black holes. But their proto-galaxies were. ...
Furious Arcturus's user avatar

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