Proposal #126

AAVSO Alert Notice 688 describes the next eclipse of the triple system b Per. The eclipse only lasts about 2 days centered on January 19, but the researcher wants monitoring from about Jan 5 through February 2. This will be a primary eclipse, with the third star (C), which has a 705d orbit, passing in front of the AB pair (1.5d orbit). Out of eclipse data is needed to calculate the offsets between observers, taking into account the 0.06mag ellipsoidal variation caused by the AB pair.

I would like to use BSM_NH2 for monitoring this eclipse. The field is at a good RA and Dec for relatively long time series, and NH2 is about as far east as you can go in the US, hopefully extending the time baseline for the actual eclipse. We took u'BVr'I data during the November 2018 eclipse to test feasibility of u' monitoring, with good success, but were clouded out during the actual eclipse. A few nightly observations will be made before and after the eclipse, with time series during the window January 17 through January 21. Observations will be submitted to the AID.