SUNSET: 
0
Photographer:
Jon Greif
Location of Photo:
Alpine, CA, USA
Date/Time of photo:
May 29-30, 2024, from 9:30 pm to 4:00 am PDT
Equipment:
Takahashi FSQ-85 mm refractor, Rainbow Astro RST-135 mount, ASI Air Plus controller, Pixinsight 1.8.9 processing software.
Description:
This is Messier 13 or M13, the Great Globular Cluster in the constellation Hercules. M13 is 22,200–25,000 light-years from Earth, about 145 light-years in diameter, and is composed of several hundred thousand stars, with estimates varying from around 300,000 to over half a million. Messier 13 was discovered by Edmond Halley in 1714, and cataloged by Charles Messier on June 1, 1764. The 1974 Arecibo message, which contained encoded information about the human race, DNA, atomic numbers, Earth's position and other information, was beamed from the Arecibo Observatory radio telescope towards M13 as an experiment in contacting potential extraterrestrial civilizations in the cluster. This image is from 5.75 hours of exposure time last night -- an especially clear sky night in Alpine.
