M13 - Great Globular Cluster in Hercules 21/08/07 - Eric Walker

M13 - 25,100 light years away. Several hundred thousand stars in cluster. 145 light years across. Around 14 billion years old. Globular cluster M13 was selected in 1974 as target for one of the first radio messages addressed to possible extra-terrestrial intelligent races. Taken from Beinn View Observstory, Conon Bridge, fairly early on the evening of 21 August 2007 (around 10:45pm BST) and the skies weren't totally dark at this latitude (57°N). Got focus pretty good (Hartman mask) but there was some high thin cirrus cloud present.Canon EOS 400D attached afocally to Meade 8" SCT with no focal reducer. ISO 1600, f/5.8, 30 & 45 second exposures. 7/11 images stacked with Registax V4 then further processed using Photoshop CS and NeatImage. www.astrophotos.plus.com