Cepheid variable - RS Peppis is one of the brightest known Cepheid variable stars in the Milky Way galaxy. A Cepheid variable (/ˈsɛfiːɪd/ or /ˈsiːfiːɪd/) is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude.
The #DolphinNebula is a red - white star of magnitude 3.3, 176 light-years from Earth. It is the brightest star in Dorado. Beta Doradus is a notably bright Cepheid variable star. It is a yellow-tinged supergiant star that has a minimum magnitude of 4.1 and a maximum magnitude of 3.5. 1040 light-years from Earth, Beta Doradus has a period of 9 days and 20 hours.
This NASA/ESA Hubble Space Telescope image shows the spiral galaxy NGC 3021 which lies about 100 million light-years away in the constellation of Leo Minor (The Little Lion). Among many other types of stars, this galaxy contains Cepheid variable stars, which can be used work out the distance to the galaxy. These stars pulsate at a rate that is closely related to their intrinsic brightness, so measurements of their rate of pulsation and their observed brightness give astronomers enough…
Nasa’s Astronomy Picture Of The Day – Nearby Cepheid Variable RS Pup
Henrietta Swan Leavitt, in 1893, joins the Harvard computers, a group of women engaged in the production of astronomical data at Harvard; she is instrumental in discovery of the cepheid variable stars, which were evidence for the expansion of the universe.
The bright southern hemisphere star RS Puppis, at the center of the image, is swaddled in a gossamer cocoon of reflective dust illuminated by the glittering star. RS Puppis rhythmically brightens and dims over a six-week cycle. It is one of the most luminous in the class of so-called Cepheid variable stars. - Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)