Cepheid variable stars exhibit regular pulsations whose period directly correlates with their intrinsic brightness (absolute luminosity). The Leavitt law establishes this relationship between ...

Yardsticks are very useful around the house when you need a measurement. (I have also used them to fish out toys the cat knocked under a low piece of furniture.) They are standards by which we can ...

The cosmic distance ladder employs a series of methods to measure increasingly vast astronomical distances, with each technique building upon the previous one for verification. Parallax, using stellar ...

Researchers using the testbed interferometer at Palomar Observatory have achieved the best-ever distance measurement to a type of star known as a Cepheid variable. The new results improve the "cosmic ...

Kochanek, Stanek, Prieto / Ohio State U. The galaxy M81, seen here in an image from the Large Binocular Telescope, is home to several ultra-long-period Cepheid variable stars that could help ...

In 1925, Edwin Hubble's observation of Cepheid variables in the Andromeda galaxy revolutionized astronomy, proving the existence of galaxies beyond the Milky Way. This discovery, aided by telescopes ...

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 ...

A persistent, nagging problem with the expansion speed of the Universe may not require a rewrite of everything we know about physics. New measurements taken using the James Webb Space Telescope ...