How is the distance to stars and galaxys measure.?

Answer 1

Another distance they use to compare distances between stars is parsecs which is 3.26 light years. Between galaxies, they use megaparsecs which a 1000 parsecs.

Answer 2

Nearby stars, within a couple hundred light years, can be measured using parallax, where the star is seen in a SLIGHTLY different direction from 2 points in Earth's orbit 6 months apart. All other measurements of more distant objects depend on figuring out how bright a star or galaxy is really and then computing how far away it must be to look as dim as it does.

Answer 3

Parallax is interesting in showing just how far away are the stars.

The Earth's orbit is about 300 million kms across (186 million miles).

If you imagine this as the base of a triangle with the sides of the triangle meeting at the very nearest star (a very skinny isosceles triangle), the angle at the apex is about 1/4000th of a degree.

So, you see, measurements of stellar distances by the parallax method requires very sensitive equipment, and gets increasingly harder as you go beyond the nearest stars.

Answer 4

Astronomers use a number of methods to determine the distance to stars and galaxies. Some terms you should research are:
stellar parallax
Cepheid variable stars as standard yardsticks
Redshift of galaxy light spectrum to determine distance

Answer 5

Typically, in light years, which is 186,000 miles a second. You can do the math from there. (approx. 5 trillion miles)

Answer 6

par secs