Object: Messier 2 or M2 (also designated NGC 7089) is a globular cluster in the constellation Aquarius, five degrees north of the star Beta Aquarii. It was discovered by Jean-Dominique Maraldi in 1746, and is one of the largest known globular clusters.
M2 is about 55,000 light-years distant from Earth. At 175 light-years in diameter, it is one of the larger globular clusters known. The cluster is rich, compact, and significantly elliptical. It is 13 billion years old and one of the older globulars associated with the Milky Way galaxy. M2 contains about 150,000 stars, including 21 known variable stars. Its brightest stars are red and yellow giant stars. The overall spectral type is F4. M2 is part of the Gaia Sausage, the hypothesised remains of a merged dwarf galaxy.
Taken: September 2, 2019
Telescope: Astro-Tech 14” RC with 0.65x focal reducer
Mount: Paramount ME II unguided
Camera: ZWO ASI1600MM-Pro (cooled to -15C; unity gain) Bin 2×2.
Focuser: Moonlite Nitecrawler
Filters used: Red, Green, Blue on a ZWO 8 position filter wheel
Exposures: Red: 6×120 sec. Green: 5×120 sec Blue 4×120 sec for a total exposure time of 30 minutes; calibrated with 14 dark frames, 33 flat frames with 33 dark-flats
Seeing Conditions:
Processed with PixInsight and Photoshop CC 2020