I was able to observe Mercury on March 19, 2011 (00:00 U.T.) over the western horizon (~23.5*) using my friend’s excellent Meade 8-inch (20-cm) F/10 ACF SCT at 120x. I was impressed with the fact that albedo features were visible over the planet while using an aperture down to 4 inches (10 cm) at a friend’s observatory. The seeing over the western horizon at sunset (twilight) was very erratic but while airing for moments of steady seeing I was rewarded by the features noted below.
Date (U.T.): March 19, 2011
Time (U.T.): 00:00
CM 77.8*W, Ls 128.5*, De -5.3*, Ds 0.1*
-0.7m, p 60%, 6.7″
Instrument: Meade 8-inch (20-cm) F/10 ACF SCT
Filters: None (IL)
Seeing (1-10): 4-6, Antoniadi (I-V): III-IV
A digital image produced in Photoshop CS5.
Carlos E. Hernandez