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Full-Text Articles in Astrophysics and Astronomy
Photometric And Spectroscopic Observations Of An Optical Candidate For The X-Ray Source H 0544 - 665, M. Van Der Klis, J. Van Paradijs, P. A. Charles, J. R. Thorstensen
Photometric And Spectroscopic Observations Of An Optical Candidate For The X-Ray Source H 0544 - 665, M. Van Der Klis, J. Van Paradijs, P. A. Charles, J. R. Thorstensen
Dartmouth Scholarship
We present the results of spectroscopic and UBV observations of the brightest star in the error box of the X-ray source H 0544–665. This object is a B0–1 V star and a member of the LMC. It shows correlated variations in brightness and colour indices. We suggest that it is a Be-type star observed during a stage of low emission strength. Although a relation between this star and the X-ray source has still to be proven the present data add considerable support to the proposed identification.
Extreme Variability In The Be-Type, Periodic Recurrent X-Ray Transient A0538 - 66: A Highly Eccentric Interacting Binary, P. A. Charles, L. Booth, R. H. Densham, G. T. Bath, J. R. Thorstensen
Extreme Variability In The Be-Type, Periodic Recurrent X-Ray Transient A0538 - 66: A Highly Eccentric Interacting Binary, P. A. Charles, L. Booth, R. H. Densham, G. T. Bath, J. R. Thorstensen
Dartmouth Scholarship
We present optical spectroscopy and photometry and IUE spectroscopy of the counterpart of the extremely powerful LMC recurrent X-ray transient A0538 – 66. During one 16.6 day outburst cycle at the end of 1980 December the optical spectra show steadily increasing Balmer and He I emission (indicative of an expanding envelope) superposed on a B2 III–IV spectrum. There is a substantial optical brightness increase of 2 mag at the peak, accompanied by the sudden turn-on of He IIλ 4686. These and other optical spectra show significant radial velocity changes but we can find no clear correlation with the 16.6 …