Delta Scorpii Still Showing Off
Delta Sco is a large, hot, rapidly rotating star of spectral type B0 about 400 light-years away. Spectra show that it began throwing off luminous gas from its equator when the outburst began. A fainter companion star orbits it in a very eccentric, looping orbit; the two stars swing close by each other (separated by about 20 times the primary star’s diameter) every 10.6 years. The last time this happened was in the summer of 2000, suggesting that this particular pass somehow triggered the flare-up. No one knows what Delta Sco will do next.