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

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

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.

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H. Saio, C. Cameron, R. Kuschnig, G. A. H. Walker, J. M. Matthews, J. F. Rowe, U. Lee, D. Huber, W. W. Weiss, D. B. Guenther, A. F. J. Moffat, S. M. Rucinski, D. Sasselov. 2006-09-16. MOST Detects g-Modes in the Late-Type be Star beta CMi (B8Ve). https://doi.org/10.1086/509315

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