A variable star is, quite simply, a star that changes brightness. A star is considered variable if its apparent magnitude (brightness) is altered in any way from our perspective on Earth. These ...

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 ...

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 ...

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 ...

Henrietta Leavitt joined the Harvard College Observatory as a volunteer in 1895. She was appointed to the permanent staff in 1902, and eventually became chief of the photometry department. She worked ...

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 ...

This week on Looking Up guest host Caitlyn Voige illuminates a luminary by the name of Henrietta Swan Leavitt. When we look up into the night sky, stars look immeasurably small and distant, unchanging ...

Today, we know that the Universe is filled with billions upon billions of galaxies; however, in the early 1900s, it was widely accepted that the Milky Way was a single collection of stars with nothing ...

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 ...