Open Star Cluster in Sagittarius ... Messier 21
(Click on Picture for larger view)
Added July 29, 2019 ...
Messier 21 (NGC 6531)is a compact open cluster in the constellation of Sagittarius within that arm of the Milky Way, which is positioned less than one degree northeast of the Trifid Nebula (M20). It contains about 60 stars, mostly white but with a sprinkling of blue giants. It is about 4,200 light-years away and is about the same age as our sun, 4.6 billion years. It is medium high in the south at midnight in July. Click on the picture for a larger view.
The Milky Way in Sagittarius:
(Hover over the picture for definitions ... Click on it to enlarge)
I took this 15 minute wide view of the Milky Way with my Canon T7i piggy-backed atop the telescope. Here you can see the 'Milkiness' of the core of our galaxy. Within this region lies several 'Messier Objects' including M 17, also known as the Omega Nebula. Jupiter was off to the right and as you can see, it moved a bit toward the east (left).
The Techy Stuff ... For those who want to know ...
Telescope: 11" Celestron Edge HD at f/7
Reducer: Celestron 0.7X Focal Reducer
Camera: Altair Hypercam 294c Pro TEC
Sensor Temperature: -5°C (23°F)
Filter: Baader UHC-S Light Pollution
Capture software: #SharpCap Pro V 3.2
Guiding: PHD 2 (RMS error: 0.29 ... i.e. very good tracking)
Mount controls: Celestron PWI V2.1.25
Polar Alignment: QHY Pole Master
Light Frames used: 44 at 180 seconds / Gain: 7,000
Dark Frames: 40
Bias Frames: 40
Flat Frames: 40
Stacked in Deep Sky Stacker
Post Processed in PixInsight and Photoshop CC
Seeing Conditions: 9 (0-10, where 0 is total cloud cover)
Moon: No Lunar Interference
Bortle Light-Pollution zone: 4.5 (can barely see the Milkyway)
Air Temperature: 72°F
Date: July28/29, 2019 from 11:50 pm - 1:10 am
Location: Backyard, Savannah GA