Direct Observations of the Orbit of Beta Lyrae
Somehow I missed this paper when it appeared on ArXiv this summer: Zhao et al, First Resolved Images of the Eclipsing and Interacting Binary Beta Lyrae, arXiv:0808.0932v1 [astro-ph], 2008. The darker blob is the donor star, and the paler blob is the thick disk that surrounds the gainer star.
Beta Lyrae is one of the longest and most intensively studied variable stars, but has only revealed its secrets very slowly. The above paper provides the first direct evidence that the two components are ellipsoidal in shape. It is interesting to see that the disk component seems flatter and fainter at phase 0.595 because there is a fairly persistent slight dip in this part of the orbital light curve. It could be that the disk is more of an asymmetric spiral, or it could be that the brighter part of the fainter component is actually the hot-spot where the gas from the donor hits the disk.
Back when I was young, I used to make visual estimates of the brightness of Beta Lyrae and use these to derive fairly crude orbital light curves.
Reader Comments