Photo of the Week for July 20, 2018
One of the most targeted summertime deep-sky objects is globular star cluster M13 in Hercules. Most would agree it’s the northern hemisphere’s finest globular even if the 5.8-magnitude specimen is not the brightest. (That honour falls to M5 in Serpens, which shines marginally brighter at magnitude 5.7.)
Under dark skies M13 is visible to the unaided eye and is a wonderful sight in any telescope. But like all globulars, M13 really comes into its own in larger scopes that are able to resolve the cluster’s myriad faint stars. Keen-eyed observers also try to spot galaxy NGC6207, positioned less than ½° northeast of M13. This distant smudge, which glows faintly at magnitude 11.4, appears at the top edge of the image presented here. (Turn to page 30 of the July/August issue of SkyNews for an article on observing M13 in binoculars.)
Kathy Walker captured this detailed portrait of M13 last June from her backyard observatory at Hall’s Harbour, Nova Scotia. She acquired a total of 88-minutes exposure data with an Orion 200mm f/4 Newtonian astrographic reflector telescope and an Atik 383L + monochromatic CCD camera shooting through Astrodon LRGB filters.