Winter 1999 MIRA Quarterly Newsletter: Looking Up

Winter 1999

Looking Up
The Transit of Mercury
with Dr. Arthur Babcock, President, ASCC

There have been fourteen transits of Mercury in the twentieth century, when the innermost planet of the solar system moves in front of the sun’s disc as seen from Earth. Since I missed the first thirteen, I made an extra effort to observe the last one, on November 15, from MIRA’s Weaver Student Observatory.

Fortunately, the weather obliged, and I was joined by Tom Lougheed, Gene Barnes, Christopher Eckles, Bruce Mendenhall and Bruce Weaver. While most of those in attendance enjoyed the spectacle through their telescopes, Bruce and I installed an ST-7 CCD camera on the 14-inch Celestron telescope in the WSO, and managed to focus it in time to catch Mercury just before it slipped off the Sun’s disc.

Coincidentally, we are approaching the maximum of the current solar activity cycle, and there were some dramatic sunspots visible, including the large group pictured below.

mercury.jpg (3804 bytes) sunspot.jpg (8743 bytes)
Mercury (at left, small black dot) ends its transit across the sun’s disk. Image taken
by Arthur Babcock and Bruce Weaver at the Weaver Student Observatory.

At right, a group of sunspots, taken by Gene Barnes using an 8-inch Celestron
Ultima with a 26.5 mm lens to project onto Fuji ASA 800 film at 1/60 exp.