Productive Seestar Session
A long period of clear autumn sky began on October 8th. That evening, after Seestar was set up outside in my backyard, I went inside to begin grabbing images for as long as I could stay awake. A good number were added to my Messier collection. When I quit after midnight, temperature had dropped to 53 degrees, and I had captured 14 images. Only four of the most interesting images are displayed below.
First is decent-sized globular cluster M12 in the constellation Ophiuchus. I've found10-minute exposures like this one work well for globular clusters.
I added open cluster M37 in Auriga to my Messier collection with the 5-minute exposure shown next.
Another example is open cluster NGC7789 in Cassiopeia. This cluster, also called Caroline's Rose, is incredibly rich. The next 5-minute exposure displays it well. It was discovered in 1783 by William Herschel's sister, Caroline, who was a very accomplished observer in her own right.
Why didn't Messier include the previous two clusters in his catalog? If he could observe M37 with his equipment, he should have been able to see NGC663 and NGC7789 as well. I don't know the explanation.
As this night ended I had added ten more Messier objects to my collection bringing my total to 71 out of 110.
