This week we look again at a non-YSO variable. It is the Mira type star KS Cyg, which is situated in the MWSC3274 target region. We showed some V-band data of this source in week 116.
In the above plot we show the B, V, and R band data. The I-band data saturates during the maxima and has hence been taken out. The star seems perfectly periodic. Neither the period (just under 300 days) nor the amplitudes have changed compared to the last time we looked at it. The variations in V are about 5mag from maximum to minimum, i.e. the flux changes by a factor of 100. The object is also extremely red, i.e. B-I=6mag at maximum. thus, the I band saturates during the maxima and the star becomes undetectable for our observers in B during the minima.