22 November 2007

Observing Location	MO
Observational Period	2000-2130 EST
Atmospheric Conditions	Cloud Cover Scattered Clouds Temperature 60° – 45° F Wind Gentle Breeze gusting to Moderate Breeze Humidity Moderate Feels Like Mild but blustery It had rained earlier this evening and the skies have cleared off enough that I could see a star or two out of my bedroom window so I went up to the oval to check on 17P/Holmes. There was still some light clouds around and the nearly full Moon was lighting up anything there was in the atmosphere. It didn’t feel moist out but the sidewalks were still wet from the rain and there were a few puddles around. It was windy and there were leaves and plastic bags being blown along the ground everywhere. Seeing was not that great. Whole sections of the Moon were going out of focus pretty much all the time. Transparency Good Seeing III
Instruments	Golden Gate 7x35 binocular - Charlie SAR: Coulter CT-100 Newtonian reflector - Charlie Celestron Omni 20mm (21x) Celestron Omni 2x Barlow
Observing Party	Charlie Ridgway

Target 17P/Holmes Constellation Per Category Comet Time yyyymmdd.hhmm 20071122.2040 EST 2007 Nov 23.07 UT Comments The comet was hard to see tonight in the binocular and even harder to see in the telescope. I didn’r make a brightness assessment but based on nearby field stars I estimated its size to be ~45’. At first I thought it was about half the distance between 31 Per and HIP 15779, 1.1°, then I increased that estimate to .66% to .75% of the distance. In the image below the red circle is 45’ in diameter and I think it fairly represents the sixe of the comet that I estimated, but I saw it lower and to the right not extending as far as 31 Per. \ Cartes du Ciel graphic

Target Moon Constellation Ari Category Lunar Time yyyymmdd.hhmm 20071122.2045 EST Comments Lunation 1050 Phase Waxing Gibbous Age 13d2h41m Distance Light Time (from earth) 353,140 km 1.17s Elongation 157.7° E % Illuminated 96.3% Morning Terminator Colongitude (λ E) 69.9° Evening Terminator Colongitude (λ W) 249.9° Libration in Latitude -5° 71’ Libration in Longitude -1° 40’ Magnitude -12.4 Angular Size 33'57" Altitude 61.2° Virtual Moon Atlas graphic Terminator Outside Feature Inside <<< Lichtinberg   <<< Briggs   <<< Seleuces   Grimaldi >>> Sirsalis >>> Crüger >>> Carwin >>> Byrgius >>> Schicard >>> Wargentin >>> Phyocytides >>> Longmontanes >>> Maginus >>> Heraclitus >>> Clavius >>> Porter >>> There were rays going in all directions from Tycho. Mare Australis, Mare Undarum and Mare Spumans were all dark and easily seen.