Binary Parameters for the Massive Eclipsing Binary CC Cassiopeiae

The O8.5III star CC Cas is in a 3.336 d eclipsing binary system that was observed in Sectors 18 and 19 of the TESS mission. We collected nearly 40 new spectra of the binary in the last year, which have been measured to determine both the primary and secondary star velocities. We have begun modeling the system’s light curve and radial velocity curve with the PHysics Of Eclipsing BinariEs (PHOEBE) code. We will present modern masses, radii, and temperatures of this O star binary in this poster presentation based on the TESS data and new radial velocities.