Special Notice #406: KIC 02856960 entering eclipse window

August 7, 2015:  Further to AAVSO Alert Notice 525, we are entering the critical period of observations for KIC 02856960.  Time series observations are urgently requested for this eclipsing binary beginning immediately (2015 August 07, JD 2457242) and continuing for the next five days, through the end of 2015 August 12. KIC 02856960 is at an approximate magnitude of V=16.0, with the expected ampltidue of the eclipse being less than 0.08 magnitudes.  The optimal S/N of observations is around 100, but observers are asked to obtain as high a signal to noise as possible with net exposure times less than 10 minutes.  If individual observations do not reach SN of 100, please submit them anyway, and they will be combined by the researchers during analysis.  Observations in any of Ic, V, Rc or clear filters are encouraged; multicolor observations are only requested if the total set of filtered images can all be obtained within a single 10-minute window, otherwise only one filter should be used.

KIC 02856960 is located at the following (J2000) coordinates:

RA: 19 29 31.52 , Decl: +38 04 35.9

The eclipse is predicted to show very complex structure over the next several days, and observations from all longitudes are urgently requested.  **Observers in central and eastern Asia and the Pacific Rim are especially encouraged to participate** along with all of our observers in North America and Europe.

Charts for KIC 02856960 may be generated via AAVSO's VSP:

https://www.aavso.org/vsp

A comparison star sequence is available; observers are encouraged to use the two comparisons labeled "148" and "151" closest to the variable if possible.

Please submit all observations promptly to the AAVSO via the WebObs feature of the AAVSO website:

https://www.aavso.org/webobs

Please use the name "KIC 02856960" when submitting all observations.

This AAVSO Special Notice was prepared by M. Templeton.