b Persei may have entered eclipse around JD 2457033.6 (2015 January 11.1 UT)

PTS

Photometry by P. Benni (AAVSO observer code BPAD;Massachusetts, United States), D. Collins (CDK; North Carolina, United States),F. Campos (CFRA; Catalunya, Spain), and F. Melillo (MFR; New York, UnitedStates) suggest that b Persei may have entered eclipse around JD 2457033.6(2015 January 11.1 UT).  Time-seriesphotometric bservations of this bright star are urgently requested beginningimmediately, and continuing for the next two weeks (through at least 2015 January26 UT) and possibly beyond.  Observationswill support ongoing optical interferometry of this system by Zavala et al. asdescribed in Alert Notices 476 and 507, and Special Notice 333.

b Persei is composed of a close binary pair with shortperiod (around

1.5 days) that produce ellipsoidal variations, along witha third object that eclipses the central pair once every ~ 700 days.  Observations of this longer eclipse will helpconstrain the properties of the system.  

For more information about this campaign, please see thefollowing

website:

               http://inside.warren-wilson.edu/~dcollins/bPersei/

b Persei is located at the following (J2000) coordinates:

               RA:04 18 14.62 , Dec: +50 17 43.7

b Per is a bright star (V=4.598, B-V=0.054) and so isideal for observers with photoelectric photometers or those using DSLRcameras.  

Please see AAVSO Alert Notice 507 for more details aboutobservations and suggested comparison stars.

Please promptly submit all observations to the AAVSO viaWebObs, using the name "B PER".

This AAVSO Special Notice was prepared by M.Templeton.