Charles Messeier discovered this Globular Cluster in the constellation of Sagittarius in 1764 ans described it as a "nebula without stars".
Nowadays it can easily be ssen,dissolved into single stars,with instruments of 8"-aperture and bigger.
By a magnitude of 7.5mag and sized slightly larger than 10 arc-minutes it is located in a very star-rich region and therefore shows yellowish colors caused by interstellar dust-absorption.
The real distance to us is 17.900 light-years with a diameter of about 80 light-years.Twelfe millisecond pulsars were detected in M28 since 1986,the third largest number of pulsars in a globular cluster yet known.
RA.: 18h 24m 32,9s
Decl.: −24° 52′ 11″
LRGB image with L = synth.of all, RGB = 6x1200s each,a total of 6.0 hours
80cm f/7 AstroOptik Keller corrected cassegrain FLI Proline 16803 Astrodon LRGB GenII filters
Prompt 7 CTIO/UNC Chile,remote controlled
image processing: Bernd Flach-Wilken
this picture of M28 shows 87% of the FOV from our eqipment.Click here to get full resolution
here is a more detailed look to M28:
a look to M28 with the HST can be seen here