A 421 d Activity Cycle in the BeX Recurrent Transient A0538-66 from MACHO monitoring

C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. C. Becker; D. P. Bennett; P. A. Charles; K. H. Cook; A. J. Drake; K. C. Freeman; M. Geha; K. Griest; M. J. Lehner; S. L. Marshall; K. E. McGowan; D. Minniti; C. A. Nelson; B. A. Peterson; P. Popowski; M. R. Pratt; P. J. Quinn; C. W. Stubbs; W. Sutherland; A. B. Tomaney; T. Vandehei; D. L. Welch

doi:10.1046/j.1365-8711.2001.04041.x

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A 421 d Activity Cycle in the BeX Recurrent Transient A0538-66 from MACHO monitoring

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Abstract

We present a ~ 5-yr optical light curve of the recurrent Be/X-ray transient A0538-66 obtained as a by-product of the MACHO Project. These data reveal both a long-term modulation at P = 420.8 +/- 0.8 d and a short-term modulation at 16.6510 +/- 0.0022 d which, within errors, confirms the previously found orbital period. Furthermore, the orbital activity is only seen at certain phases of the 421 d cycle suggesting that the long-term modulation is related to variations in the Be star envelope.

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C. Alcock, R. A. Allsman, D. R. Alves, T. S. Axelrod, A. C. Becker, D. P. Bennett, P. A. Charles, K. H. Cook, A. J. Drake, K. C. Freeman, M. Geha, K. Griest, M. J. Lehner, S. L. Marshall, K. E. McGowan, D. Minniti, C. A. Nelson, B. A. Peterson, P. Popowski, M. R. Pratt, P. J. Quinn, C. W. Stubbs, W. Sutherland, A. B. Tomaney, T. Vandehei, D. L. Welch. 2000-09-26. A 421 d Activity Cycle in the BeX Recurrent Transient A0538-66 from MACHO monitoring. https://doi.org/10.1046/j.1365-8711.2001.04041.x

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