An Etymological Dictionary of Astronomy and Astrophysics

A → supernova of Type Ia in the constellation → Cassiopeia, which Tycho Brahe observed in November 1572. At its peak it was as bright as Venus and was visible in the daytime, reaching a magnitude of about -4. It is now visible as a → supernova remnant about 20 light-years across at a distance of about 7,500 light-years. It is associated with faint emission in the optical and X-rays, but is a strong radio source.
Other designations: SN 1572, 3C 10, B Cas, 2U 0022+63.

See also: Named after the Danish astronomer Tycho Brahe (1546-1601), who described the event; → star.