Cepheid variable
A Cepheid variable is a type of variable star that pulsates radially, varying in both diameter and temperature. It changes in brightness, with a well-defined stable period and amplitude.
Amateur astronomy
Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes.
Butterfly Cluster
The Butterfly Cluster is an open cluster of stars in the southern constellation of Scorpius. Its name derives from the resemblance of its shape to a butterfly.
21P/Giacobini–Zinner
CometComet Giacobini–Zinner is a periodic comet in the Solar System. It was discovered by Michel Giacobini, who observed it in the constellation of Aquarius on December 20, 1900.