posted on Jan, 15 2013 @ 05:50 PM
It is called scintillation, caused by turbulence in the atmosphere.
Stars suffer from it due to being so far away and so little light reaching us.
Planets do not twinkle unless there is really high turbulence in the atmosphere, and even then, they don't twinkle much, so what you are seeing is
most likely a star.
It would help if you could give us a location (direction, I can see you are in the UK) and time so we can narrow down which star it is you are looking
edit on 15/1/13 by woogleuk because: (no reason given)