Sketch of Ptolemaeus and Surroundings
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Observation Notes:
Despite the bad seeing, Ptolemaeus and friends were large and stark enough to put on a good show at 120X. An interesting pillar of shadow within Ptolemaeus seemed bulbous at its tip. It seems likely that this little feature is caused by crater Ammonius. Spörer was a fairly rugged crater compared to deep Herschel. Lunar curvature was beautifully obvious across Ptolemaeus’ expansive floor.
| Subject | Ptolemaeus and Surroundings |
| Classification | Craters |
| Position | 9.2°S, 1.8°W |
| Phase/Age | 8.1 Days / 57% Illuminated |
| Size* | Ptolemaeus: 153 km dia x 2400 m depth Ammonius: 9 km dia x 1850 m depth Alphonsus B Herschel: 41 km dia x 3770 m depth Spörer: 28 km dia x 310 m depth Gylden: 47 km dia |
| Date/Time | AUG 27, 2009, 10:00 PM MST (AUG 28, 2009, 05:00 UT) |
| Observing Loc. | Flagstaff, AZ – Home |
| Instrument | Orion SkyQuest XT8 (203 mm dia./1200 mm F/L) |
| Eyepieces/Mag. | Pentax XW10 (120X) |
| Conditions | Mostly clear, calm |
| Seeing | Ant. IV |
| Sources | Atlas of the Moon by Antonín Rükl 2004 |
* Based on published data.