Mercury Transit, 8 Nov. 2006 (Weds)

by Bob Jardine

Observing Report -- 8 Nov. 2006 -- Mercury Transit from Cupertino and Mountain View

IIRC, Kepler was the first to predict a transit of Mercury and attempt to observe it. He was clouded out, and he also miscalculated slightly. I knew that I wouldn't miss this transit due to miscalculations (thanks to Kepler and others who followed in his footsteps, most recently Fred Espenak), but I was worried about being clouded out!

Early in the week, the weather predictions were looking grim, but they started to improve on Tuesday, so I decided to risk not taking a road trip. This was somewhat of a relief: I was prepared to do a road trip if necessary, but I had lots of work to do.

It was quite cloudy/overcast when I awoke on Wednesday, but the satellite images showed a relatively narrow band of clouds advancing across the bay area from NW to SE, and the animation showed that it would likely clear. What a great tool! Just as the satellite images showed it clearing a little bit North of here, I could finally see blue skies to my North. And it cleared up quickly just around 10:30, with the Transit predicted to start at about 11:12 PST.

I observed ingress from home (Cupertino), then packed up the telescope and took it to work (Mountain View). I showed mid-transit to my co-workers just after lunch, then viewed the egress from work just after 4PM.

I viewed with a 7" Teleport (fl about 1000 mm) with aperture mask around 60mm, 24 Panoptic and 11 Nagler.

Here are the times (all PST) I got for the four contacts:

First -- 11:13:10 (or a bit earlier)
Second -- 11:14:30
Third -- 16:07:53
Fourth -- 16:09:30

(My watch was 3 seconds fast earlier in the morning according to the "official" US time web site; the times above have not been adjusted for this 3-second offset, but my observations are probably +/- way more than 3 seconds anyway.)

First contact could have easily been 10 or 30 seconds before I noticed it, but the other three times should be closer. Third and fourth contacts were somewhat difficult to judge, because they occurred at much lower altitudes, and there was a lot of atmospheric distortion at that point.

I enjoyed the three sunspots that other observers mentioned, one large one just a bit North of the ingress point and two smaller ones just North of the egress point.

Posted on sf-bay-tac Nov 09, 2006 09:53:07 PT
Converted by report.pm 1.4 Dec 12, 2006 22:04:05 PT