Beta Doradus

Characteristics

Beta Doradus is a Cepheid variable that regularly changes magnitude from a low of 4.08 to a high of 3.46 over a period of 9.84318 days. The light curve of this magnitude change follows a nearly regular saw-tooth pattern, with average amplitude variations period to period about 0.005 magnitude from average amplitude of 0.62 magnitude. During each radial pulsation cycle, the radius of the star varies by 3.9 R_☉ around a mean of 67.8 R_☉. Its spectral type and luminosity class are likewise variable, from F-type to G-type and from a supergiant to a bright giant.

Far ultraviolet emissions have been detected from this star with the Far Ultraviolet Spectroscopic Explorer, while X-ray emissions were detected with the XMM-Newton space telescope. The X-ray luminosity is about 1 × 10²⁹ erg/s and the emission varies with the pulsation period, suggesting a connection with the pulsation process. The peak X-ray emissions are in the 0.6–0.8 keV energy range, which occurs for plasmas with temperatures of 7–10 million K.