A close globular cluster at only 7.2k light years. This cluster is very close to the bright red star at the heart of Scorpius, Antares. The individual stars are pretty easy to resolve visually even with a small telescope. Being low in the sky for those of us in the northern hemisphere, it is a treat to observe on a clear still night. From the Southern hemisphere this globular is quite a sight! Straight up in the sky. I had the opportunity to see this cluster with binoculars from an Island due east from Sao Palo Brazil in June when it was right at the meridian. Incredible! Someday I hope to have a good telescope and mount in Brazil and spend some quality time with this impressive cluster.

The night I took this image my plan was to image the trifid nebula in Sagittarius. The sky was very good when I arrived at my dark site. It takes me about 1.5 hours to get set up and ready to image once I park my car. By the time I had the scope aligned, guiding ready to go etc. the entire sky was covered with clouds, except for due south. This is where I intended to image, so I felt pretty lucky. I had about 90 minutes before the trifid would be on the west side of the meridian, where I usually image, so I started with this globular. The clouds stayed put and I felt pretty smug. Once the 90 minutes had pasted, I stopped imaging M4 and told the mount to find M20, the trifid. I always use the "high precision" feature on my mount which has me center a bright star close to the object I am looking for and then the computer always gets the object centered in my camera. Well, I didn't notice that the star the computer suggested was still on the east side of the meridian and I hit the go button. The scope slewed all the way around to the star I had agreed on, about a 300 degree turn. I frantically worked all of the cables plugged in the camera, guider etc. so they didn't get caught on something as the scope moved. Center the star and then slew back almost a full 360 degrees, more cable management. On the way back my cables got crossed and I lost power to the mount. If the sky were clear of clouds, no big deal just realign the scopes computer. But since 3/4 of the sky was covered with clouds, I couldn't see any stars to run the alignment on. Not so smug about my small area of clear sky all of a sudden. Pack up and go home.

The real irony is that my mount has a function for just that situation. Use the last alignment. But of course at 2 am one's mind is not as sharp as it might be, so the joke was on me in the end.

Details:
Date : 5/31/09
23 x 90 second exposures with a modified Canon Rebel XT
William Optics 110mm FLT TMB Triplet
IDAS Filter
Celestron CGE Mount
Processed with Deep Sky Stacker, PixInsight LE and Photoshop CS3