The simple answer is that the intrinsic brightness of these variable stars is strongly tied to their period. This is the famous period-luminosity relationship discovered by Henrietta Leavitt more than ...

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 ...

Cepheid variables are pulsating supergiant stars whose regular brightness variations are tightly correlated with their intrinsic luminosities. This period–luminosity relation, often termed the Leavitt ...

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 ...

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 ...

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 ...

Using ESA's XMM-Newton spacecraft, astronomers have conducted X-ray observations of a peculiar Cepheid variable star known as V473 Lyr. Results of the study suggest that this star has a young, ...

Since the 1960s, a class of specialpulsating stars hasstymied scientists attempting to weigh them. The two main ideas for howto measurethese stars' masses have so far produced vastly different results ...

Photo: Andromeda nebula plate with Hubble's handwritten circle around the variable star he discovered In 1919 American astronomer Edwin Hubble began work at the Mount Wilson Observatory in California, ...

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 ...