

AT12 RC modification and cleaning
It has already been two years since the Astrotech 12'' RC became the workhorse of Asteria observatory. It has already logged tens of hours of imaging during that time, specifically close to 150 hours. They say you're not supposed to clean the optics at all if possible, due to the thin aluminum coating that may be affected. However there came a point where I could see a layer of gunk caked on the mirror's surface, which would eventually start to affect performance by lowering


Galaxies galore (Abell 1656 cluster in Coma Berenices)
Can you count all the galaxies? This field is just 25x15 arc minutes. Only a quarter of a degree across. Yet, not unlike the Hubble Deep Field image, it is hard to believe how many galaxies are visible in such a small patch of sky. The galaxy brightness range is from 11.5 - ~19 magnitude. According to a quick search in the SIMBAD database, it appears that some of the fainter galaxies are so far away, their light took around half a billion years to to reach my camera sensor. S