Bullialdus – July 10, 2011

2011 07 10, 0255UT Bullialdus
Erika Rix, Ohio, USA – www.pcwobservatory.com
Bulllialdus: Complex crater from Copernician period (-1.1 billion yrs to present day), Lat: 27.7 deg south, Long: 22.2 deg west.

Zhumell 16”, 21-7mm Zhumell, 257x, no filter
Eyepiece sketch on Strathmore Artagain paper, Conte’ crayon, charcoal

Temp 20C, 92% humidity, S: Antoniadi III, T: 2/6
Phase: 65.5deg, Lunation: 8.75d, Illumination: 70.7%
Lib. Lat: +5deg21’, Lib. Long: +2deg21’
Az: 212deg51’, Alt: 23deg30’

My first thought was to get out my Rite in the Rain paper and charcoal, but that terminator line was looking very dramatic and I decided to try another lunar sketch with black paper and white pastels. I chose the white on black because it can be a lot quicker to draw highlights than to draw shadows and I knew there would be a race against time to sketch on the terminator line. Thanks to my friend, Rich Handy, for introducing me to this media. I’ve found it invaluable for my h-alpha solar work.

Something didn’t really look right to me during my observation. It was only when I called it a night and came back in the house that I realized that Bullialdus A looked a lot larger (and Bullialdus B for that matter) than normal. There’s not a real sharp northern edge to Bullialdus A. It almost has a plateau-like bridge connecting it to the crater Bullialdus. The lighting played against that (or that explanation seems reasonable to me) to make it appear larger than normal.