Astronomy help please? About galaxies, etc?

H

Hahayoufailbigtime

New member
Galaxies obviously rotate around a central point. Well, which should move faster..the stars near the center of the galaxy or the stars in the outer reaches?

What is the arrangement of the AGE of the stars in the milky way? In other words....where are the young and the old stars located?

If the universe is expanding right, why does Andromeda galaxy exhibit a blue shift?

Hubble's law states that there is some kind of correlation between galaxy distance from us and their speed movement away from us. What is the correlation?

What are the waves in the Cartwheel Galaxy caused by?

And lastly, where is the red smoky dust from the cigar galaxy coming from?

* Test coming up soon in my astronomy course, any help would be greatly appreciated *
 
Its really quite amazing how much information can be found online with just a bit of searching.

Galaxies do not appear to conform to Kepler's laws of motion.

In our galaxy, young stars are in the spiral arms, older stars are in the halo.

Andromeda is actually moving towards us.

The farther the galaxy, the faster its moving away.

Shock waves from the passage of a nearby galaxy.

Its not smoky dust, its hydrogen gas from intense starburst activity.
 
Well, it depends. If you look at an artificial satellite orbiting the Earth, the closer it is (low earth satellite) to the Earth, the faster it moves. The further away (geosynchronous satellites), they move slower. It works the same with stars - except instead of an Earth, it's a supermassive black hole AS WELL as the bulge of our galaxy.

As for the Andromeda galaxy, you're thinking of something called the "Doppler Effect". It explains why as a motorcycle approaches you, the pitch changes when it moves away. The sound waves are compressed and form a higher sound when it's moving towards you (think of a slinky) and as it passes you and moves away, the sound waves stretch apart, making a lower pitched sound. It works the exact same with light, except instead of sound - it's the visible spectrum. As a galaxy or source of light moves towards you, the light waves compress and shifts to the BLUE end of the spectrum (called a blue shift) and as it moves away the light waves stretch apart and it moves to the RED end of the spectrum (called a red shift). That means the Andromeda galaxy is moving towards us. And to explain the expansion - space-time is really messed up. When you think of air particles in a syringe and you pull back the plunger (when almost all the air has been pushed out - and cover the tip with your finger!) the air particles will still be moving in their directions. It's just that the spaces between them will change a bit. Even with that happening, they still collide with each other.

Scientists can tell how far a way a galaxy or star is by using the spectrum (red shift, blue shift), triangulation (mathematical ratios) to tell exact distance, and something called a parallax. This is when you close your eye and look at something, and you close the other eye and look at the same object, it seems to shift. It works the same with distance - except instead of eyes we're using two or more telescopes. The less the shift, the farther away.

The red smoky dust may be coming from a baby galaxy. The dust is starting to heat up and form stars.

I hope I was help :)
 
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