Variable Stars - V488 Per
Type BY Draconis Click for lightcurve BY Draconis-type variables are emission-line dwarfs of dKe-dMe spectral type showing quasi- periodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag. in V. The light variability is caused by axial rotation of a star with a variable degree of non-uniformity of the surface brightness (spots) and chromospheric activity. Some of these stars also show flares similar to those of UV Ceti stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables. AAVSO Special Notice #408  October 2, 2015 Developing planetary systems dust production study - second segment of observations further to AAVSO Alert Notice 511, issued in March 2015.  Dr. George Rieke (University of Arizona) and colleagues' campaign to monitor planetary debris disks for variability using the Spitzer Space Telescope continues. AAVSO observations are requested to rule out variability of the stars themselves. The second segment of observations of the four targets takes place from now into January 2016 according to the schedule below. Mar 14-Apr 24 Oct 10-Nov 20
Hills Observatory: 1 January 2013 to 10 July 2018
COMETS COMETS
DEEP SKY DEEP SKY