Great work on a very difficult object Chris. I wondered what the altitude of Mercury was when you imaged it?  Can you confirm the time was 9.30BST. I also wondered how you managed to find the planet?

cheers

Martin

Thanks for your comment, Martin. My imaging session on Saturday lasted about an hour between 10 and 11 am BST, so I put the time as 0930 (UT). According to Stellarium Mercury was at an altitude of 50 to 54 degrees.

Finding it is fairly straightforward with a polar-aligned mount. Mine is an HEQ-5 Pro, which also gives a coordinate read-out on the handset. I start from the Sun (with a sub-aperture solar filter), then make offsets in RA & Dec calculated from the coordinates read from Stellarium. A key point is to focus on the Sun, so I know that when I remove the solar filter and start looking for Mercury it will also be in focus. I use a crosswire eyepiece so the focus of my eye doesn't wander while looking for a pale white speck in an expanse of blue sky. Good transparency is important: any slight haze or cirrus can make spotting the planet much harder.

Hi Chris,

Thanks for the reply that is very interesting. Lots of top tips to help in finding the planet in the daytime.

I could use a similar method but using alt and azimuth on my Dobsonian calculated from Sky Safari. Always wanted to image surface  detail on Mercury but never wanted to risk scanning around too much close to the sun.

Thanks again

Martin