Tags: Star.
V509 Cassiopeiae (V509 Cas) is a star in the constellation Cassiopeia. V509 Cassiopeiae is yellow hypergiant with a G-type and an apparent magnitude that has varied from below +6 in historical times to a peak of +4.3 and now around +5.2. It is around 4500 light years from Earth. It is classified as a semiregular variable star of type SRd. Characteristic periods around a year are reported imposed on the slower secular variations.