NGC6121 or M4 in Scorpius
NGC6121, M4, is a globular cluster in Scorpius.
Visually, M4 is noted for the bar of stars across its core and
a stirrup or arc of stars (above the bar in this picture).
Large telescopes and pictures of M4 are so bright
that these feautres are difficult to see.
Hover over the picture for an annotated version
Date: 6 and 7 July 2024
FOV: cropped to 60' × 40'; M4 is approximately 23'
Telescope: Stellarvue SVX102T + SFFX-1 flattener (714mm, f/7)
Guiding: ZWO ASI120MM mini mono guide camera,
Stellarvue F050G 50mm guide scope
Computer: ASIair pro Raspberry Pi
Mount: iOptron CEM40
Camera: ZWO ASI071MC Pro Cooled (-10°C) Color CMOS with gain 90
Pixel size: 4.78 μm
Resolution: 1.334 arcsec/pixel
Filter: Optolong UV/IR cut
Stacking: sixty-seven 240 second frames using Pixinsight
Total Time: 4 hours 28 minutes
Processing: Pixinsight – Crop, SPCC, DBE, BXT, NXT mask,
GHS, HST, MStr, PMath MStr + GHS + HST → PM, Sat, Scale
Location: Cherry Springs State Park near Coudersport, PA