Stars type that helps measure universe & are use to detect other astronomical anomalies
The direct relationship between a Cepheid variable’s luminosity and pulsation period makes them important for scaling galactic and extragalactic distances.
This Classical Cepheids was discovered in 1908 by Henrietta Swan Leavitt after studying thousands of variable stars located in the Magellanic Clouds.
This discovery allows one to know the true luminosity of a Cepheid by simply observing its pulsation period. This in turn allows one to determine the distance to the star, by comparing its known luminosity to its observed brightness.
Isaaac Asimov short story “Blind alley”
Near extinct Aliens on a “Zoo Planet” that Escaped to the Magellanic Clouds
more from story
The few remaining members of the only intelligent non-human alien race the Galactic Empire has discovered have been removed from their dying planet and transferred to the much more pleasant Cepheus-18 (hence their name, “Cepheids”).