Pictures of the day: 17 December 2012 We open today's gallery with two photos taken by a Telegraph reader. Vlad Lapadatescu, a computer science engineer based at CERN in Switzerland, writes: "This was created from stacking several hundred photos together. Each photo had an exposure duration of 15 seconds. It was taken in France, at an observatory managed by the AstroQueyras association, at more than 2,900m in altitude...."Picture: Vlad Lapadatescu / www.flickr.com/photos/stormlv/