Question

Question 1 (33%) Galaxy Distance In s0.5 pages of text, how did Edwin Hubble prove that "spiral nebulae" were in fact galaxies? Why was this important (hint: think of the scale of the universe)?

THIS IS THE DETAILED QUESTION

'Foundations of Astronomy'; Ryden, Barbara; Peterson, Bradley

Answer 1

Explanation :

Edwin Hubble proved that "spiral nebulae" were galaxies.

He was an astronomer from America. He worked in astronomy and observational cosmology. He has given a law termed as Hubble's law. This law has given first evidence on the expension of the universe.

V1 ia one of the class of the pulsulating star. It is used to find the lager distances. He plot a light curve by taking certain values of V1. As a result he find the period of 31.4 days. He then find its distance from the earth which is approximately equal to 1 million light years.

It is also known that the spiral nubulae is smaller than milky way galaxy. So, it is understood that it is a part of galaxy.

This shows the spiral nebulae were a galaxy and also the expansion of universe.