The Andromeda Galaxy (M31) lies nearly 3 million light-years from Earth, while the Virgo cluster of galaxies extends 50 million light-years into the “local” universe. Have you ever wondered how ...

The new results, from a team led by Grzegorz Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), appear in the Nov. 25, 2010 edition of the ...

Since the 1960s, a class of special pulsating stars has stymied scientists attempting to weigh them. The two main ideas for how to measure these stars' masses have so far produced vastly different ...

Cepheid variables are yellow super-giant stars that pulsate variably, changing in diameter and temperature. These shifts cause the stars to change brightness in a predictable manner. The strong ...

How is astronomical distance determined? Just cannot get my head around cepheid variables, parallax, etc. How is it possible to tell how far away something is when you cannot bounce a radar beam off ...

Publications of the Astronomical Society of the Pacific, Vol. 119, No. 854 (April 2007), pp. 398-406 (9 pages) ABSTRACT We introduce a simple method for determining pulsation velocities of Cepheid ...

In commemoration of Edwin Hubble's discovery of a Cepheid variable class star, called V1, in the neighboring Andromeda galaxy 100 years ago, astronomers partnered with the American Association of ...

A new analysis of pulsing stars has revealed the Milky Way’s twisted shape. Scientists have known since the 1950s that the spiral-shaped Milky Way’s disk is warped, bending by thousands of light-years ...

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical Society in January 1925, a paper read by one of his ...

Today's ESA/Hubble Picture of the Week features a galaxy that Hubble has captured multiple times over more than 20 years. The galaxy is called NGC 3370, and it is a spiral galaxy located nearly 90 ...