Special Notice #394: Observations of b Persei urgently requested

January 12, 2015: 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, United States) suggest that b Persei may have entered eclipse around JD 2457033.6 (2015 January 11.1 UT). Time-series photometric observations of this bright star are urgently requested beginning immediately, and continuing for the next two weeks (through at least 2015 January 26 UT) and possibly beyond. Observations will support ongoing optical interferometry of this system by Zavala et al. as described in Alert Notices 476 and 507, and Special Notice #333.

b Persei is composed of a close binary pair with a short period (around 1.5 days) that produces ellipsoidal variations, along with a third object that eclipses the central pair once every ~ 700 days. Observations of this longer eclipse will help constrain the properties of the system. For more information about this campaign, please see the following website:


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 is ideal for observers with photoelectric photometers or those using DSLR cameras. Please see AAVSO Alert Notice 507 for more details about observations and suggested comparison stars.

Charts for b Per may be created using the AAVSO Variable Star Plotter (VSP, http://www.aavso.org/vsp).

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

This AAVSO Special Notice was prepared by M. Templeton.


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