The VISTA telescope observed the Trifid Nebula, identifying previously hidden variable stars. These variable stars exhibit a period-luminosity relationship, meaning their intrinsic brightness is ...

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 ...

Stellar distances are primarily determined by the inverse-square law of light, which mathematically links a star's apparent brightness (m), intrinsic brightness (absolute magnitude, M), and distance ...

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 ...

Comparison of simulation of three main star forming episodes in the spiral arms with the currently observed Cepheid variables. Oldest stars (red) are 400 million years old and the youngest (blue) are ...

We derived the distances for the five Cepheids from near-infrared photometry obtained with the Infrared Survey Facility (IRSF) and we used radial velocities from the Southern African Large Telescope ...

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 ...

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 ...

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 ...