possible microflare on EV Lac

Sat, 01/11/2020 - 02:45


I would appreciate comment or critiscm on an observation I made back in August, 2019. I was using a Star Analyzer 200 on a 12-inch LX-200 while observing the star EV Lacerta with a cadence of 4 frames/minute. At about 720 UT the star brightened by about 0.1 mag and then returned to normal about 8 minutes later. I caught this event by constructing a differential photometry light curve using the zero order image of the star and picking several reference stars and a check star in the field. As I was recording spectra as well I compared these spectra to ones taken a few minutes after the event. I have posted these  as well as made a short animation by blinking the two frames. This animation can be seen as a recent post on the Mark Slade Remote Observatory  (2remotetelescope) FB page. I will try posting a link here as well.


The changes are a slight enhancement of the H Gamma and H Delta emmission lines, as well as an overall slight increase in the flux of the blue end of the spectrum. These changes are much easier to appreciate while viewing the animation. Although I did calibrate the individual images, and applied an instrument response to the spectra, it is still possible these changes are artifacts as they are subtle. Thats where I would appreciate help from more experienced members of this forum.


Myron Wasiuta