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

Saio, H.; Cameron, C.; Kuschnig, R.; Walker, G. A. H.; Matthews, J. M.; Rowe, J. F.; Lee, U.; Huber, D.; Weiss, W. W.; Guenther, D. B.; Moffat, A. F. J.; Rucinski, S. M.; Sasselov, D.

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

Authors

Description

The Microvariability and Oscillations of stars (MOST) satellite has detected low-amplitude light variations ($Δm\sim$1 mmag) in the Be star $β$ 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 ($\approx 3.5 M_\odot$) 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