A Cepheid variable (/ ˈ s ɛ f i. ɪ d, ˈ s iː f i-/) 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.. A strong direct relationship between a Cepheid variable's luminosity and pulsation period established Cepheids as important indicators of cosmic benchmarks for scaling ...

Cepheid is an American molecular diagnostics company. Its systems automate traditional nucleic acid tests (tests for specific sequences of DNA or RNA).The tests can be used to identify and analyze pathogens and genetic disorders.Cepheid sells clinical tests for healthcare-associated infections, infectious diseases, sexual health, oncology and genetics.. The cartridges used in …

It is a classic Cepheid variable, the closest to us in the whole Milky Way. Polaris B can be seen even with a modest telescope. It was found by William Herschel in 1780 using one of the most powerful telescopes of the time: his own reflecting telescope. The nearby dwarf star, Ab, was predicted in 1929, but only seen quite recently.

Mu Cephei (μ Cep), aussi nommée l'étoile Grenat, l'étoile grenat de Herschel ou Erakis, est une étoile supergéante rouge de la Voie lactée, dans la constellation de Céphée, à 5 200 al du Soleil.. Elle doit son surnom d'étoile Grenat à sa couleur rouge éblouissante, remarquée pour la première fois par William Herschel [2].. C'est l'une des étoiles visibles les plus volumineuses ...