Further Evidence for a Black Hole in β Lyrae

Abstract

DEVINNEY¹ has shown that the observational peculiarities of the binary system β Lyrae can best be understood in terms of the secondary mass being a collapsed star (black hole) surrounded by an opaque or nearly opaque disk. This communication points out that the recently released² ultraviolet photometry from the Orbiting Astronomical Observatory (OAO) leads to the same conclusion. Fig. 1 shows the light curves of β Lyrae given in ref. 2, for which the stated accuracy is ± 0.01 magnitude. One might have some reservations about these observations because the shorter wavelength light curves fail to close after one cycle and the presentation (hand-drawn curves instead of the original observation points) is counter to normal practice. It may, however, be a very long time before confirming observations of this extremely interesting binary can be gathered, and they do relate in an important way to the question of whether β Lyrae contains a collapsed star. Kondo et al.² mentioned briefly the possible presence of a black hole in the system, but not for the reason advanced here.