how long does it take for our galaxy to rotate once?

Answer 1

It takes the sun 250 million years to rotate around the galaxy. However, the galaxy rotates at different rates depending on the distance from the center.

Answer 2

The Solar System, made up of the Sun, the Earth and the other planets, and lots of smaller stuff, orbits around our Milky Way Galaxy in about 240,000,000 years. Each object in the galaxy orbits at a rate that depends on how far out it is from the center. Astronomers know this as "Kepler's 3rd Law" and it tells us that the outer part of the Milky Way takes about 3-4 times longer to orbit than does the Solar System, meaning about 1 Billion years! The spiral arms thus bend backwards because the parts farthest from the center take longer to orbit.
In the center of the Milky Way , a place named Sagetarius A-star and written as "Sag A*", things orbit very quickly. Some we have seen using very long wave length infra-red light have orbited in a single Earth year! We think there is a huge Black Hole at the center and that the Milky Way orbits around that.

There is something else strange going on. The outer parts of the galaxy orbit faster than we think thry should! This suggests that there is a source of lots of extra gravitational force that we can not see, and this problem is one of the most exciting areas of astro-physics today.

Answer 3

approx 200 - 220 million years.

Interestingly enough, the spiral arms of galaxies tend to move as a "gravitationally cohesive" form which maintains shape and structure ... implying that stars far from the center of a galaxy tend to obey the same "galactic-year" even tho they have to cover a longer trajectory to do so ....

kinda spooky, but true and explainable using only newtonian physics

and "up/down" motion relative to the galactic plane seems to have other effects on life on earth:

"... suggesting that the Sun and Earth passed through a region of far more debris approximately 13 million, 39 million, 65 million, 91 million, 117 million, etc, years ago. Paleobiologists seem to have found some evidence for repetitive mass extinctions of species at around those pseudo-periodic dates."

Answer 4

The diameter of the Galaxiy is 100 000 light year. the circumference is aprox =Pi x the diamenter.The rotation is equal to The period of revolution would be the circumference divided by the orbital velocity.
If the orbit velocity was equal to the speed of light than the period would be numerical equal to the Circumference in Unis of years
One Galactic revolution relative to the Big Bang center would be aproximately rounded off =45 billion years.
At that rate unless a total revamping of the Universe occurs in the Future ,the revolution of galaxies are so slow that they would appear to astronomeers as standing still..

Answer 5

The galaxies are actually not in orbit around he centre of the universe - to all intents and purposes the universe does not have a centre. besides the incontrovertible fact that, they do actually rotate. we've direct observational evidence for this. If we check out the Andromeda galaxy, case in point, we see one side slightly crimson shifted and the different side is slightly blue shifted. this means that one element is shifting faraway from us and the different in the direction of us. Assuming the galaxy isn't tearing itself aside meaning it would desire to be rotating.

Answer 6

the real question is how long does it take for our galaxy to rotate around the center of the cosmos and how long does all the galaxies take to rotate around the cosmos and how long does it take for the cosmos to rotate around the mega verse.... and so on and so forth

Answer 7

I went outside and did a quick estimate of movement I saw, then extrapolated.
I'd say about 250 million years.
I checked with NASA, and they agree with me.

Answer 8

a VERY long time

oh and I think the girl below me thought you were talking about Earth..

I'm not sure about the milky way, but I know it takes a looonnnggg time.

Answer 9

one day. that is why the sun comes up and sets. we learned about that in the 4th grade.