Variations of the amplitudes of oscillation of the Be star Achernar

Abstract

We report on finding variations in amplitude of the two main oscillation frequencies found in the Be star Achernar, over a period of 5 years. They were uncovered by analysing photometric data of the star from the SMEI instrument. The two frequencies observed, 0.775 c/d and 0.725 c/d, were analysed in detail and their amplitudes were found to increase and decrease significantly over the 5-year period, with the amplitude of the 0.725 c/d frequency changing by up to a factor of eight. The nature of this event has yet to be properly understood, but the possibility of it being due to the effects of a stellar outburst or a stellar cycle are discussed.

6 pages, 6 figures, 1 table, to be published in MNRAS

References in corpus (4)

• Wide-field mid-infrared and millimetre imaging of the high-redshift radio galaxy, 4C41.17
• The close-in companion of the fast rotating Be star Achernar
• Oscillations in Beta UMi - Observations with SMEI
• SMEI observations of previously unseen pulsation frequencies in gamma Doradus

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• The binary system of the spinning-top Be star Achernar
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