I'm doing a summer internship and my supervisor is currently away and uncontactable. He left me details of certain hubble images to download and analyse asking for HST images of M31 with coordinates 00:42:52.534 +41:18:54.17 on 2006-07-15 and 2007-01-12. (YYYY-MM-DD) The problem is that observations on these dates for M31 do not exist on the hubble archive. Nearby dates do not have enough of the field to be aligned with one another and there is also the issue of different exposure times. I would have posted this in the hubble forums but it's down at the moment afaik. Can anyone point me in the right direction?