Tuesday, May 2, 2017

Our Galaxy and Other Galaxies

Our Galaxy and Other Galaxies




8 comments:

  1. How many galaxies, on record, are there?

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    1. Hubble has estimated about 100 billion galaxies in our universe!

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  2. There is evidence that there is a super massive black hole at the center of spiral and eliptical galaxies, but is there any evidence of there being a super massive black hole at the center of a irregular galaxy that every thing orbits around even though in some cases of irregular galaxy there is no definitive center?

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    1. After doing some research, I think the answer is yes! All large galaxies have black holes.

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  3. There is evidence that there is a super massive black hole at the center of spiral and eliptical galaxies, but is there any evidence of there being a super massive black hole at the center of a irregular galaxy that every thing orbits around even though in some cases of irregular galaxy there is no definitive center?

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  4. You state that spiral galaxies usually contain young blue stars, elliptical galaxies usually contain older stars, and irregular galaxies usually contain new stars. So, would elliptical galaxies more star formation going on? Also, have there been spiral and irregular galaxies discovered that contain more older stars?

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    1. Elliptical galaxies would not have more star formation going on. Eventually, stars die. That is, essentially, what is happening in an elliptical galaxy. I did not find anything about spiral and irregular galaxies containing older stars, but I would assume they might. All stars might be a different age, so compared to other stars, they might be older.

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  5. Do we know why all galaxies have black holes in the center of them.

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