Michael A. Stecker
The initial sighting of the M22 globular cluster was by A. Ihle in 1665.
Thus making it the first globular cluster known. It is about 33 arcminutes
in diameter and magnitude 5.2. It is therefore slightly larger and brighter
than M13. M22 can be found in Sagittarius about 2.5 degrees northeast
of the star Lambda Sagittarii.
Photographic Data: An Astrophysics 155 mm f/7 refractor with Pentax
6x7 camera and 2X Pentax teleconverter (Effective Focal Length =
2170 mm) were used for this color image. Two 45- minute exposures
were made with non-hypered Kodak Pro 400 PPF-120 film while
centered at RA 18 hrs, 36 min and Declination - 24 degrees. A composite
of the two negatives was made, processed and cropped in the computer.