MOST Detects g-Modes in the Late-Type be Star beta CMi (B8Ve)

Abstract

The Microvariability and Oscillations of stars (MOST) satellite has detected low-amplitude light variations ($\Delta m\sim$1 mmag) in the Be star $\beta$ CMi (B8Ve). The observations lasted 41 days and the variations have typical periods $\sim 0.3$ days. We demonstrate that the dominant frequencies are consistent with prograde high-order g-modes of $m=-1$ excited by the Fe-bump of opacity in an intermediate-mass ($\approx 3.5M_{\odot }$) star with a nearly critical rotation period of 0.38 days. This is the first detection of nonradial g-mode pulsations in a Be star later than B6 leading to the possibility that pulsations are excited in all classical Be stars.

17 pages, 6 figures; Astrophysical Journal part 1 in press

References in corpus (1)

• Most Detects G- and P-Modes in the B Supergiant HD 163899 (B2Ib/II)

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