24 September 2007

Observing Location	TotL
Observational Period	2030-0100 EDT
Atmospheric Conditions	Cloud Cover Clear Temperature 68° - 66° F Wind Calm to Moderate Breeze gusting to 22 MPH Humidity High Feels Like Cool It was fairly nice early then the wind started to pick up and the air felt moist so I was chilly. I put a fiber pile vest under my windbreaker and was still a little cool. It got really gusty after midnight and then the sprinklers came on along the fence line and the wind blew the water across the walk where we were set up. Transparency Excellent Seeing II-III
Instruments	SAR: Coulter CT-100 Newtonian reflector - Charlie Celestron Omni 20mm (21x) Celestron Omni 2x Barlow Takahashi 102mm F/8.2 refractor - Peter 1.5" TeleVue Plossl 32mm, ##° FoV, 31.8x 1.25" TV Nagler 13mm, 82° FoV, 97.7x 1.25" TV Plossl 7mm, 82° FoV, 181.4x Nikon 10x42 Monarch ATB binocular - Kin
Observing Party	Charlie Ridgway Peter Tagatac Charlie Ridgway

Target Jupiter Constellation Oph Category Planet Time yyyymmdd.hhmm 20070924.2130 EDT Comments Object Class Classical Planet Elongation 71.8° E Distance Light Time (from Earth) 5.51 AU 45m50s Distance (from Sun) 5.28 AU Angular Size 35.7"x33.4" Magnitude -2.0 Central Meridian I/II 170°/202° Altitude 6.1° Moons Starry Night Starter graphic I could see Callisto and Ganymede on the western side of the planet and Io out alone on the east. In Peter’s scope I saw Europa as a pimple on the eastern limb and when he bumped the power up it separated from the disk as a pale salmon dot.

Target (4) Vesta Constellation Oph Category Asteroid Time yyyymmdd.hhmm 20070924.2145 EDT Comments Object Class Asteroid Dwarf Planet candidate Distance Light Time (from Earth) 2.15 AU 17m53s Distance (from Sun) 2.18 AU Elongation 78.2° E Magnitude 7.5 Not Seen I tried hopping to Vesta from both Jupiter and η Oph and got lost both times when I got into the neighborhood of δ Oph.

Target Moon Constellation Category Lunar Time yyyymmdd.hhmm 2007 EDT Comments Lunation 1048 Phase Waxing Gibbous Age 13d13h15m Distance Light Time (from earth) 963,930 km 1.21s Elongation 156.1° E % Illuminated 95.7% Morning Terminator Colongitude (λ E) 71.4° Evening Terminator Colongitude (λ W) 251.4° Libration in Latitude +0°39’ Libration in Longitude -5°13’ Magnitude -12.2 Angular Size 32'56" Altitude 36.5° Virtual Moon Atlas graphic Peter and I spent a long time working down the length of the terminator trying to identify all the craters along it. One of us would look in the scope and call out what he say and the other would look at my S&T Field Map of the Moon identifying things that were seen and that were missed. Then we would switch places so that we each had a chance to see everything. We saw a lot but neither of us made any notes so I have had to back things out using Rükl’s Atlas of the Moon and Cherrington’s Exploring the Moon Through Binoculars and Small Teliscopes. Working from north to south we saw, or didn’t see,: Pythagoras; 130 km, class 1, contains a central peak; just inside the terminator Babbage; 144 km, young; not as visible as it was last night Anaxamander; 68 km, class 5; I am not sure I saw it Oenopides; 67 km, very old; visible as a ridge of light in the terminator Mons Rümker; 70 km; Well inside the terminator. It took a bit of work and high power but I finally found it. It was easy to see in SAR at 22x Harding; 23 km; I think this was just outside, or maybe just inside, the terminator Briggs; 37 km, young Seleucus; 43, class 1 Hevelius; 106, class 5; I think this one was mostly in the dark Grimaldi; 430, class 5; just inside the terminator Sirsalis, 42, class young; well inside the terminator. Slightly overlaps Sirsalis A. Rimae Sirsalis passes through Sirsalis J and Sirsalis F which are two much smaller craters adjacent to the rim of Sirsalis and following the alignment of Sirsalis and Sirsalis A. Piazzi; 101 km; mostly in the terminator and hard to tell what it was Schicard; 227 km, class 5; well inside the terminator Schiller; 179x71 km, class 3; well inside the terminator Segner; 67 km, class 3; forms a line well inside the terminator with Zucchius, Bettinus, Kircher and Wilson Zucchius; 64 km, class 1 Bettinus; 71 km, class 1 Kircher; 73 km, class1 Wilson; 70 km, very old, rounded rim makes it hard to see Bailly; 303, just inside the terminator. Also saw Bailly B on the floor of Bailly At the end of the night I spent some time examining the area around Aristarchus. I could see both Aristarchus and Herodotus and the arc of Vallis Schöteri and farther out to the NW a thin line of Montes Agricola. It looked like there might have been a large crater wall to the NW or Aristarchus which looks more like a mound in Rükl. LAC indicates that this is a complicated area of increased elevation with lots of ridges and valleys. Extending to the SW from that area past Schiaparelli and Seleucus is a line of color that gives me the impression of a bench or scarp, higher on the side to the NW. LAC shows lines of ridges in this area but they have not been assigned names. detail from LAC plate 38

We got soeaked when the sprinklers came up at about 0045 EDT. They didn’t used to come on this late. They came on right along the fence line where a lot of the water gets sprayed into the fence and over the sidewalk and is wasted. It was worse tonight than usual since the wind was variable but mostly blowing out of the south.

On the way out of the park we stopped in the path leading past the Metropolitan Museum and quickly observed the Pleiades and Mars.