The Mercury transit 9 May 2016

I haven’t been able to use my telescopes for a couple of months, but the Mercury transit couldn’t be missed. Back home after work I set up and began observations at 15:00 UT. I was treated with a clear blue sky and acceptable seeing. For the observation I used my trusted 10″ SkyWatcher dobsonian, masked down to 4″, and a 17 mm Baader Hyperion eyepiece (for 70x). I followed the transit for about an hour and a half. By that time the sun had dropped towards the horizon and the seeing deteriorated.

Times as indicated on the sketch. Subtract 2 hours for UT.

Not as impressive as the Venus transit a couple of years ago, I still found the slow progress of Mercury over the face of the sun fascinating to observe. The planet was small, very distinct (of course), and nicely framed by to sunspot groups: AR2542 the larger group at the bottom and AR2543 close to the center of the solar disc. The direction of Mercury’s movement was difficult to pinpoint, and might be a bit off.

I also tried to capture the event with my (handheld) cell phone. Below is the best of several tries.

The Mercury transit captured with a handheld Samsung cellphone.