high-mass X-ray transient

Alert Notice 562: Photometry of V725 Tau needed immediately

November 15, 2016: Dr. Franco Giovannelli (Istituto di Astrofisica e Planetologia Spaziali di Roma) has requested AAVSO assistance in monitoring V725 Tau, the Be star in the high-mass X-ray transient A0535+26/HDE245770, in order to plan for the X-ray outburst that follows 8 days after the optical brightening that occurs at periastron passage.

Periastron passage will occur on 16 November 2016, so coverage is needed beginning immediately and continuing for at least 15 days after periastron, until December 2.