1306.1236 (Ellyn K. Baines et al.)

Characterization of the Red Giant HR 2582 Using the CHARA Array    [PDF]

Ellyn K. Baines, Harold A. McAlister, Theo A. ten Brummelaar, Nils H. Turner, Judit Sturmann, Laszlo Sturmann, Christopher D. Farrington, Norm Vargas, Gerard T. van Belle, Stephen T. Ridgway

We present the fundamental parameters of HR 2582, a high-mass red giant star whose evolutionary state is a mystery. We used the CHARA Array interferometer to directly measure the star's limb-darkened angular diameter (1.006+/-0.020 mas) and combined our measurement with parallax and photometry from the literature to calculate its physical radius (35.76+/-5.31 R_Sun), luminosity (517.8+/-17.5 L_Sun), bolometric flux (14.8+/-0.5 e-8 erg s-1 cm-2) and effective temperature (4577+/-60 K). We then determined the star's mass (5.6+/-1.7 M_Sun) using our new values with stellar oscillation results from Baudin et al. Finally, using the Yonsei-Yale evolutionary models, we estimated HR 2582's age to be 165 +20/-15 Myr. While our measurements do not provide the precision required to definitively state where the star is in its evolution, it remains an excellent test case for evaluating stellar interior models.

View original: http://arxiv.org/abs/1306.1236