Sinus Iridum

Sketching: For this sketch I used: Black Canson sketching paper, 9”x 12”, White and black Conte' pencils, a blending stump, plastic eraser. After scanning, contrast was decreased (-2) using the scanner. Telescope: 10 inch f/ 5.7 Dobsonian and 9mm eyepiece 161x Date: 8-15-2009 10:00 – 11:20 UT Temperature: 16° C (60° F) clear, calm Seeing: Antoniadi II Co-longitude: 206.3° Lunation: 24.3 days Illumination: 32.1 % Observing Location: +41°37' +87° 47' Oak Forest, Il.