3 May 2007

Observing Location	SIBL
Observational Period	1030 EDT
Atmospheric Conditions	Cloud Cover Clear Temperature 58°F Wind Calm Humidity Low Feels Like Very comfortable There is no obvious cloud but the glow around the Sun indicates the presence of high, thin clouds or haze. There is some boiling evident on the limb of the Sun. Transparency Good Seeing II
Instruments	Canon 15x50 IS binocular w/Baader AstroSolar filter film - Charlie
Observing Party	Charlie Ridgway

Target Sunspots Constellation Ari Category Solar Time yyyymmdd.hhmm 20070503.1030 EDT Comments Distance Light Time 1.008 AU 8ms Angular Size 31'47.1" Altitude 50.6° Heliographic Latitude (B0) -3.95° Heliographic Longitude (L0) 282.63° Position Angle (P) -23.74° Carrington rotation number (CR) 2056   Groups Spots R North 0 0 0 South 1 2 12 Total 1 2 12 R = (Groups * 10) + Spots) Group 953 Heliographic Latitude -7° Heliographic Longitude 300° Carrington rotation number (CR) 2056 Mcintosh System Eko The group looks like a J with a fat bottom and a small ascender so I am sure that there are at least two spots there, one on the bottom and another in the ascender. There is a broad penumbra surrounding both spots.

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We are coming up on a period of favorable libration for Mare Orientale, which I have never seen. Looking at the little dots next to the little moons in the Observers Handbook 2007 it looks to me like we might have a chance of seeing the feature tonight through the 15th of the month with libration being most favorable on Wednesday, 9May07 when there is supposed to be 25% cloud cover and a 10% chance of rain according to NOAA

NOAA graphic And a 60-65% chance of rain according to DryDay.com
DryDay.com graphic

Reading in the Handbook I saw where they gave dates of maximum and minimum libration through the year in both longitude and latitude so I decided to graph them to see if I could predict when would be the best time to see lunar features.

The first thing I found was a bit of linguistics concerning libration. When the moon is rotated so that we can see the greatest amount of the eastern limb that is called maximum libration while when it is rotated the other way so we see the greatest amount of the western limb that is called minimum libration. The same is done with libration in longitude, when the north pole is tipped earthward that is maximum libration and when it is the southern pole that is tipped more toward us it is minimum libration. None of my resources have explained why this is but I am assuming it is because the sign for western longitude and southern latitude is minus. I always refer to it as maximum eastern and maximum western libration.

In graphing the data I found that the change is greater in longitude by two degrees (-8° to +8°) than it is in latitude (-7° to +7°). The graph makes it look like there is a greater disparity. That is because the maximum and minimum librations in longitude each ranges over ±5° to ±8°.

The best days to see Mare Orientale should be when the blue triangle is close to a magenta square on the bottom half of the chart. The closer they are and the lower on the graph the better. Mare Marginis and Mare Smythii whould be easiest seen when the points are close together and high on the graph.

The chart does not take into account when the limb is in shadow. Although the periods 11Sep07-1Oct-7 and 20Oct07-28Oct-7 would appear to be good observing times the moon is new through waxing gibbous 11-25Sep07 and first quarter through waxing gibbous 19-25Oct07.

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Observing Location	TotL When I arrived tonight there were people out on the ball fields playing so I figured we might have a problem with the sprinklers. I checked with one of the park garbage collectors and he didn’t know if they had been turned on yet so I asked a guy driving a white electric car with the park department logo on it and he didn’t know either but was of the same opinion as I. Around 2315 EDT the infield sprinklers started coming on, but not all at once the way they used to. From then on various sets of sprinklers would come on through the time when we were leaving. No sprinklers came on at the fence line of TotL proper although they did over to the west near the robin dormitory tree. There were a couple of new sprinklers in the outfield between the two north ball fields which I hope are the ones that used to give us headaches along the fence line that have been relocated. If that is the case, and they maintain the same sprinkler schedule, we won’t have problems this year unless it is very windy, in which case we probably won’t be observing anyway. But they had two schedules last year so we need to be careful for a while and see if the schedule changes over the next couple of weeks.
Observational Period	2000-0130 EDT
Atmospheric Conditions	Cloud Cover Clear Temperature low 60s-high 50s F Wind Calm Humidity Moderate Feels Like Cool There wasn’t any cloud tonight but there was an occasional ring of illuminated haze around things as small as Saturn and definitely around the Moon. There was boiling on the limb of the Moon, and the fainter moons of Saturn weren’t always visible. Transparency Good Seeing II
Instruments	SAR: Coulter CT-100 Newtonian reflector - Charlie ~24mm Kellner w/helical focuser (18x) Celestron Omni 20mm (21x) Celestron Omni 2x Barlow SAR wasn’t terribly well behaved tonight. I couldn’t get the red dot finder anywhere near lined up. And all the stars were very much comet-like. Venus, Saturn, the Moon and Jupiter all had ghost images around their upper left quadrant. Takahashi 102 refractor - Peter
Observing Party	Charlie Ridgway Peter Tagatac Kin Lee

Target Venus Constellation Tau Category Planet Time yyyymmdd.hhmm 20070503.2015 EDT Comments Object Class Classical Planet Phase Waning Gibbous Meridian graphic Elongation ° % Illuminated 66.8% Distance Light Time (from Earth) AU ms Distance (from Sun) Au Angular Size 17" Magnitude -4.12 Altitude 33°2’ It was still fairly light out but Venus was all flare, with a comet tail. It did look nice sitting next to β Tau.

Target Saturn Constellation Leo Category Planet Time yyyymmdd.hhmm 20070503.2025 EDT Comments Object Class Classical Planet Elongation ° Distance Light Time (from Earth) AU hm Distance (from Sun) Au Angular Size "x" Ring Angular Size "x" Ring Inclination ° Magnitude +0.4 Altitude 63°57’ Meridian graphic I tried it in SAR while it was still twilight and could only see Titan. The view was best if I moved the planet off axis to the upper left of the FoV. We got it several times in Peter’s scope at various magnifications. There I saw Titan, Tethys and Iapetys and at times Rhea. We thought we had seen another moon down near Rhea but Starry Night Starter does not indicate any others there. In his scope I could see the shadow of the planet on the rings, the stripe of color on the planet south of the rings, the C ring across the planet, and the Casinni Division on the rings at their eastern extent. Starry Night Starter graphic

Target M44, Beehive Cluster, Praesape, NGC 2632 Constellation Cnc Category DSO: OCl Time yyyymmdd.hhmm 20070503.2035 EDT Comments I found this cluster twice tonight and both times by the brute force method. I can’t see any landmark stars to point the scope, if the red dot finder had been alighned to be able to point the scope, and there is a lot of sky between it and either Pollux or Regulus, with not a lot of bright stars along the way for a star hop. I started at Saturn and just scanned the sky until I stumbled upon it. It really looks nice in the Kellner at 18x, there is breathing room around it so it doesn’t spill over the edges of the FoV. At that magnification I can detect a little stardust between the bright stars. Throwing in the 2x Barlow the view becomes dimmer and there is a bit of glow around some of the brighter stars or pairs of stars but the stardust fades. There are lots of paired stars in the cluster but the S&T Pocket Star Atlas only indicates one double star and I wasn’t able to figure out which one that would be to examine it in the scope.

Target Sword of Orion Constellation Ori Category Asterism Time yyyymmdd.hhmm 20070503.2050 EDT Comments I thought I was seeing Aldeberan but found it to be Betelgeuse so moved down through Orions Belt to the Sqord, which was only slightly above the tree line and in the dense muck. I could make out two stars at the top of the Sword, three in the middle around the Trapezium, and two at the bottom.

Target The Big Zigzag Constellation Boo Category Asterism Time yyyymmdd.hhmm 200703.2130 EDT Comments This is a big Lacerta-like grouping of stars below Arcturus that I stumbled across while trying to get to Struve 1835. It nearly fills the FoV of the Kellner. Starry Night Starter graphic In the image above the Big Zigzag is near the lower right of the to Arcturus’s 4:30 and Struve 1835 (below) is at the edge of the image below Arcturus.

Target Struve 1835 Constellation Boo Category Double Star Time yyyymmdd.hhmm 20070503.21.30 EDT Comments I found the string of three stars of which the double is the brightest at the top (bottom in my scope) but was not able to split the double. Jeremy Peres in The Belt of Venus says the separation is 6.2” so I think it is within the graps of my scope if it were performing better. I wanted to get Peter to give it a try but he was busy with a passer-by and I got off onto the Moon before he got free.

Target Moon Constellation Category Lunar Time yyyymmdd.hhmm 2007 EDT Comments Lunation Phase Waning Gibbous Virtual Moon Atlas graphic Age 16.66d Distance Light Time (from earth) 400,657 km s Elongation ° % Illuminated 97.3% Morning Terminator Colongitude (λ E) Evening Terminator Colongitude (λ W) Magnitude -12.59 Angular Size 29.82' Altitude ~14° The Moon rose in the claws of the scorpion and Peter found that it had occulted the lower claw star and it would shortly be uncovering it. I was looking at the time it came out but missed it. A passer by was in Peter’s eyepiece and when he got back to it I heard a groan and he said the star had already emerged. I had wanted to see if I could see Mare Australe tonight. I am sure that I have seen it years ago but don’t remember it. Tonight I saw Lacus Autumni in my scope and in Peter’s it looked to me like I was seeing Montes Cordillera with a peak on Montes Rook rising up through a gap in the obscuring Cordillera. We spent a lot of time on the center of the Moon tonight. In the area north of Sinus Medii I noted a C-shaped feature facing into Mare Imbrium beneath Montes Harmis of Mare Serenitatis. It appears that this is a combination of Lacus Odii (Lake of Hate), Lacis Doloria (Lake of Suffering), and Lacus Lenitatis (Lake of Tenderness). Opposite that feature near between Menelaus and Manilius there was a darn down-turned horseshoe that appears to be composed of Lacus Gaudii (Lake of Joy), Lacus Hiemalis (Winter Lake), and Lacus Lenitatis (Lake of Tenderness. I saw Dorsa Tetyaev and possibly some of Dorsa Harker in Mare Crisium. Rimae Petavius was visible as a white streak extending to the SW from the central peak of Petavius to the wall. The northern border of Mare Imbrium looks a lot broader than normal and more irregular. We looked for Stadius and found something round forming a right angle with Eratosthenes and Copernicus but it doesn’t seem to be in the right place for Stadius, yet Rulk doesn’t depict anything else in the area. Starry Night Starter graphic This view of the Moon and Jupiter is remarkably like what we saw last night. The trees just need to be a bit taller on the left.

Target Jupiter Constellation Oph Category Planet Time yyyymmdd.hhmm 20070503.~2250 EDT Comments Object Class Classical Planet Elongation ° Distance Light Time (from Earth) AU ms Distance (from Sun) Au Angular Size 44" Magnitude -2.48 Central Meridian I/II °/° Altitude 8° Moons