Astronomers have long understood that the universe is expanding—in other words, the space in between cosmic objects that aren ...

Roger Brady Tamal, California Cepheid variables are a type of star that undergo regular pulsations. The length of a Cepheid's pulsations is always related to its intrinsic, or absolute ...

The James Webb Space Telescope has confirmed the universe's expansion rate, suggesting unknown cosmic factors drive its ...

JWST researchers reported on measurements built on last year's confirmation based on Webb data that Hubble's measurements of ...

Astronomers can't agree how fast our cosmos is expanding. A new James Webb Space Telescope study has made the crisis even ...

At the center of these side-by-side images is a special class of star used as a milepost marker for measuring the universe’s rate of expansion – a Cepheid variable star. The two images are ...

New observations from the James Webb Space Telescope have reinforced the Hubble tension, a discrepancy between different ...

[B77] 63: Hubble has observed a budding star, SSTC2D J033038.2+303212, hidden in the constellation Perseus. It is in its ...

Leavitt discovered 2,400 variable stars, about half of the known total in her day. Through these discoveries came her most important contribution to the field: the study of cepheid variable stars ...

Two different space telescopes have looked at the same galaxy, so you can see the difference in how they observe the universe ...

It’s the first-ever glimpse of the surface of what astronomers called a Cepheid variable star — a very special kind. Polaris is a special kind of star for two reasons. As well as being ...

Around 1924, Hubble was looking at the Andromeda nebula and found to his amazement that one of the stars he'd observed wasn't just any star, but a cepheid variable. In 1912 Henrietta Leavitt had ...