ASTROPHOTOGRAPHY PROCESSING

Reduce star trailing in your astro images, An easy processing tip to remedy stretched and unsharp stars

Astrophotography is an extremely rewarding aspect of astronomy, but as any astro-imager will know, conditions often aren't in our favour, which is why we have to take advantage of those rare clear nights whenever they come around. It can be disappointing, then, after capturing those precious images, to discover that they suffer from star trailing.

Slightly trailed stars can be caused by a misbalanced mount or one not quite correctly aligned with the polar axis, making your stars look either stretched or appear as short lines. It would be easy to delete your images and accept that your night's work was in vain, but wait: in some circumstances, you may be able to salvage something from those images by using a simple but effective tip.

In our example we took 21 images of Brocchi's Cluster, also known as the Coat Hanger Cluster, a tiny asterism shaped like a coat hanger in the constellation of Vulpecula. On cursory examination, the stacked image looked good, but when we looked more closely we noticed the stars were slightly trailed.

Star shape enterprise