According to Mrs. Claire BARRETT of Purley, UK, the mystery "object" in the top right of this picture was snapped by her 48 year old husband on January 9, 2009. While Mr. BARRETT was taking a walk and looked up at the trees covered in frost, he spotted something moving steadily in the sky. The "thing" finally faded away in the distance. No further details are known, but what the picture shows is not mysterious at all: it's a lens flare caused by the Sun which is visible in the opposite corner of the image (move cursor over image to see how the positions of Sun and flare relate to the center of the photo).
Note also that, at the place where the solar disc should be, there is a group of smal black dots. This oddity is called the "Black Sun Effect". It is explained in the caption of photo PA-FD-04.The fact that the Sun appears as a series of multiple small dots instead of a single round dot is due to the tree branches that are positioned between the Sun and the camera.
[Photo by John BARRETT - borrowed from www.thisiscroydontoday.co.uk (image-over script by Chris POOLE)]