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M13 Globular Cluster

The M13 Globular Cluster is one of the brightest and most observed star clusters in the night sky.  It makes for a great beginner astrophotography target, as it shows up well in short exposures. This gorgeous collection of Suns is known as the Great Globular Cluster in Hercules.

The photo seen below was captured using an Explore Scientific ED80 Apochromatic Refractor, on a Celestron CG-5 Computerized GoTo astrophotography mount.

The M13 Globular Cluster

M13 Globular Cluster in Hercules


The M13 Globular Cluster is the perfect choice for a night with moonlight in the spring.  During the months of March, April and May are when I like to focus on Messier 13 from the Northern Hemisphere.  Globular star clusters like M13 can be photographed during nights with moonlight, as they are not as affected by moon glow as dim nebulae and galaxies are.

Bright star clusters such as M13, M3 and M44 can be photographed quite successfully by stacking several short exposures.  So, if you have not started autoguiding yet, or have issues with exposures longer than 30 seconds, the great globular star cluster in Hercules is a great choice.  A tracking astrophotography mount with autoguiding will help bring out the fine details and fainter stars.

Astrophotography Tracking Mount

Astrophotography Details:

Total Exposure Time: 54 Minutes
Exposure Details: 18 x 180″ Exposures @ ISO 1600

Camera: Canon Rebel Xsi (450D)
Telescope: Explore Scientific ED80
Mount: Celestron CG-5 (Since replaced by the AVX)
Autoguiding Camera: Meade DSI Pro II
Guide Scope: Orion Mini 50mm

Captured using Canon EOS Utilities
Autoguiding with PHD Guiding
Register and Stacking with DeepSkyStacker
All Processing in Adobe Photoshop

View my current astrophotography setup for deep-sky imaging


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M13 is rather small in a wide-field refractor such as the ED80 I used for the photo above.  That ED80 has a focal length of 480mm, just to give you an idea of what to expect.  The final image was substantially cropped from the original frame.

If you shoot through light pollution in your backyard like I do, globular clusters are a satisfying target.  The short exposure lengths needed help keep the city glow at bay.  A stack of 30″ exposures at ISO 800 should be more than enough to record this beautiful globular cluster from the city.  No light-pollution filters were used when capturing my image.

You might have noticed a distant galaxy in my image.  Longer exposures using a tracking mount will reveal NGC 6207 next to the M13 globular cluster.  The star diffraction spikes were added synthetically using the star spikes action in the Astronomy Tools Action Set.

Find the M13 Globular Cluster

The constellation Hercules is quite easy to identify in the Spring, even from light polluted areas.  Use the star map below to help you find the star cluster with your telescope or binoculars.  See the star chart below from Stellarium:

Messier 13 - Great Cluster in Hercules

Messier 13 as seen in Stellarium

View More of my Astrophotography Images in the Photo Gallery