hip-443

Its story

33 Piscium is an inseparable pair. Its primary is a red giant of type K0 IIIb whose chemistry reveals the «first dredge-up», the moment when core ashes rise to the surface. The two orbit each other in 72.93 days with moderate eccentricity; the system —catalogued as BC Piscium— is an RS Canum Venaticorum variable, its light modulated by active starspots. Leah Allen and Adelaide Hobe first detected its radial-velocity swing at Lick Observatory in 1911.