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Session 60 - Stellar Astrophysics I.
Oral session, Tuesday, January 16
Salon del Rey North, Hilton
We present angular size measurements of 19 oxygen-rich Mira variable stars made at IOTA (IR Optical Telescope Array). These observations are part of a long term observational program to directly ascertain the oscillation mode of these variables. From the data, the Rosseland mean diameter is calculated using the Mira atmosphere models of Scholz amp; Takeda (1987 Aamp;A, 186, 200). Estimates of bolometric flux for these stars, combined with the diameter measurements, are used to calculate effective temperatures, T_EFF. The stars observed were similar in nature and represent an extensive sample of points along a single phase cycle of Mira variables; the phase dependence of T_EFF is shown to follow simple expectations. Using distance estimates for these stars, linear sizes are also calculated, and the phase dependence of radius is discussed.
Program listing for Tuesday