M15 - Globular Cluster
- Messier 15 is a globular cluster in the constellation Pegasus. M15 is about
33,600 light-years from Earth, and 175 light years in diameter. It has an
absolute magnitude of -9.2, which translates to a total luminosity of 360,000
times that of the Sun.
Apparent Magnitude: +6.2
Apparent Dimensions: 18'
I imaged this object at the end of August with my Lepus 0.62 FR. With the moon
out the past week I decided to redo this at f/10. I more than doubled the subs
and the results are much better.
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- --- Jeff Armstrong <army5@...> wrote:
> ... redo this at f/10 ... and the results are much better.Pretty cool. Globulars need long FL, good seeing, etc. so you did the right thing in removing the reducer.
Here is my recent pic of M15 (EMCCD on C-14, fwhm = 1.4"):
Also, M15 has a small planetary nebula (rare in globular clusters) that has diameter of only 1-2 arcsec - "Pease 1". Here is an old ST-7 image that does not really resolve it but does pinpoint Pease 1 via H-a filter (try to locate Pease 1 in your image via asterisms):