[vsnet-campaign-xray 481]SwiftJ1727.8-1613: superhumps?

SwiftJ1727.8-1613: superhumps?

This X-ray transient looks like to have started showing superhumps. An analysis of the data since Sep. 17 shows a signal at 0.2116(1) d (full amplitude 0.07 mag with multiple peaks in a period). Signals at P/2 or P/3 were weaker and the 0.2116-d period appears real. This signal apparently appeared in conjunction with the spectral/state transition (ATel #16247). Considering the case of ASASSN-18ey = MAXI J1820+070 (arXiv:2107.03681, Variable Star Bulletin 74), the current variation appears to be stage A superhumps.

observers: Berto Monard, Itoh-san and Josch Hambsch