M10
Globular cluster in Ophiuchus

10.1″ f/4.5, Mallincam DS432cTEC
Exposure = 5 sec, Live Stacked frames = 21, Gain = 25 of 250

M10 appears to be a slightly lop-sided globular cluster with its brightest stars leaning more in the east direction. The core appears fairly condensed however there is a brighter and looser collection of stars spread across the face of the core; interestingly this is also evident through the eyepiece at medium-high power because that’s how I described it in a sketch on June 24, 2006: “More towards the center can see a ‘C’ of stars shining brightly in the foreground; there seem to be a multitude of other stars across the face of the cluster at this magnification that are on the edge of resolvability, twinkling in and out, perhaps as many as 30 stars.”

M10 appears to be about 20 arc minutes across; it is 14,000 light years away and 84 light years in diameter.

North at 11 o’clock, East at 8 o’clock