Imaged the globular cluster M5 on the night of July 22, 2023. M13 has an apparent magnitude (v) of 5.6 and an apparent size of ~23 arcmin.
Per NASA (reference:
https://www.nasa.gov/feature/goddard/2017/messier-5): "Discovered in 1702 by the German astronomer Gottfried Kirch, M5 is one of the oldest globular clusters in the Milky Way galaxy. With an apparent magnitude of 6.7 and a location 25,000 light-years away in the constellation Serpens, M5 appears as a patch of light with a pair of binoculars and is best viewed during July."
Imaged with a William Optics GT81 at F4.7 (382 mm focal length) using Flat6A II field flattener/0.8x reducer, UVIRcut filter, and ZWO ASI 533MC Pro. Total integration time of 1.5 hours: 43 subs at Gain = 100 with an exposure time of 120 sec.
Pre-processed using Pixinsight's weighted batch pre-processing script (WBPP) to perform calibration, debayering, registration, local normalization, and integration. Background removed using GradXpert. Initial post-processing in Pixinsight: spectrophotometric color calibration, blur x terminator, and noise x terminator. STF stretch, HDR transformation using EasyHDR script, local histogram transformation, and color saturation adjustment.
Original version: M5 OSC RGB image
Rev B: M5 OSC RGB image, inverted
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