Waid Observatory

Object: NGC 6656 - M22

Date: July. 25, 2023  -   Location: DSOC, Fort Davis, TX
Telescope: 16 inch RC  -  Camera: FLI 16803  -  Mount: Paramount ME II
Exposure: L,R,G,B 20x60 sec. each filter

Image Credit: Preston Starr and Donald Waid

Click on the image to view at higher resolution.

  NGC 6656

NGC 6656 - M22

NGC 6656, also cataloged as Messier 22 (M22), was amoung the first globular clusters to be discovered2.  Globular clusters contain some of the oldest stars in our galaxy and are the objects of considerable study and research.  M22 is located in the constellation Sagittarius(1) approximately 10,600 light years distance(2).  It is one of the brightest globular clusters observable from northern latitudes(2).  The cluster spans about 65 light-years in diameter(1) M22 is one of only four documented globular clusters containing a planetary nebula(2).  Recent studies using data collected by the Hubble Space Telescope have identified a number of planet-sized objects moving among the cluster stars{3}.  The masses of these objects have been determined to be as small as 80 times that of the Earth(3).  These "orphan planets" were discovered using a technique so-called microlensing(3), i.e. the bending of light of background cluster stars

1NORILab: https://noirlab.edu/public/images/noao-m22/
2Wikipedia: https://en.wikipedia.org/wiki/Messier_22
3Hubblesite: https://hubblesite.org/contents/news-releases/2001/news-2001-20.html <

Copyright Donald P. Waid