25 September 2007

The Old Farmer’s Almanac is predicting a “major hurricane” along the east coast somewhere between Richmond, VA, and Boston, MA, during the period 27-30Sep07.

So far I haven’t heard anything about this so I went to my usual weather sources to see if they agree.

My first stop for weather, as always, was NOAA and their weather graph for the NYC area. I had to past three of them together to cover the timeframe and it is so wide that it doesn’t look like much when it is shrunk up to fit this column, but there is less than 0.75” of rain forecast on Thursday and Friday, hardly even a tropical storm.

NOAA National Weather Service graphic

The Weather Channel is showing some thunderstorms on Thursday but otherwise some sun each day during the remainder of the period.

The Weather Channel graphic

AccuWeather says thunderstorms Thursday afternoon and night but otherwise mostly clear.

AccuWeather graphic

Weather Underground is saying 60% chance of rain on Thursday and 50% chance on Friday followed by a clear Saturday.

Weather Underground graphic

And for the ultimate in long range detailed precipitation prognostication I checked DryDay.com where they make their forecast 18 months in advance and never change it. They are saying a high chance of rain on Thursday, a higher chance on Friday, only a chance on Saturday and a low chance on Sunday.

DryDay.comgraphic

So where is this hurricane?

I checked in with the National Hurricane Center and found that Tropical Depression 11 developed late last night and was upgraded to Tropical Storm Karen early this morning. It is down near the equator between Africa and South America and isn’t even expected to make it up to Bermuda by Sunday.

NOAA National Hurricane Center graphic

The almanac also said that for 20-26Sep07 we would have rain then cool and during that period we have had above average temperatures and only 0.33” of rain on the afternoon of 22Sep07.

The Old Farmer’s Almanac got it right at the beginning of the month but lost it at the end.

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Observing Location	TotL
Observational Period	2115-0100 EDT
Atmospheric Conditions	Cloud Cover Clear Temperature 77° - 73° F Wind Gentle Breeze gusting to Moderate Breeze Humidity Moderate Feels Like Mild The wind started out light but at around 2200 EDT again tonight it picked up and became variable and gusty. It was predominantly out of the south. I got out the RadioShack anemometer and clocked a peak at 20 right after an even stronger one that prompted me to dig the instrument out, and I think it reads on the conservative side. The weather history I use on Weather Underground does not show any gusts during the period and only has winds of a Light Breeze category. I think it is windier at TotL than it is elsewhere because there is so much open space across the Lawn to the south. As soon as you start to walk east to leave the park the wind diminishes and is nearly absent when you get out onto the City streets. The NOAA observatory is up on a hill behind Belvedere Castle but there are trees all around it so the anemometer there is protected from the wind. I checked the conditions at LaGuardia Airport and they did not show any gusts but their sustained winds were more in line with those I observed. It was clear but not transparent. I had to find Mirfak in order to locate Algol each time wanted to compare its brightness to that of ρ Per. The fishhook was not visible and neither was most of the steeple and right side of Perseus. I saw between three and five of the Pleiades and only one or two of the Hyades. μ Cas wasn’t visible until the constellation was high overhead at the end of the observing session. Seeing was rock solid. I did not detect any wavering on the moon when the scope wasn’t being buffeted by the wind. The wind kept trying to tear the shroud off the scope and I finally gave up on replacing it and found that the scope was much less affected by the wind with the lessened surface area. Transparency Fair Seeing I
Instruments	SAR: Coulter CT-100 Newtonian reflector - Charlie Celestron Omni 20mm (21x) Celestron Omni 2x Barlow - w/Baader AstroSolar filter film w/Baader AstroSolar filter film Nikon 6x15 Monocular II (7.5° TFoV) - Kin This is a handy little instrument that Kin has had out before but which I have never spent much time with. There isn’t a lot of magnification there or aperture either so it isn’t great for stargazing but Kin says it is great during the daytime. He has used it with an orange solar filter and says he can see large sunspots with it. It is a wide, flat form factor that fits comfortably in both hands and can be held surprisingly steady. It has a rotation magnifying lens (9x total) that converts it into a microscope that fills the FoV with a penny. It feels light and cheap since it is plastic ( their web site says titanium and polycarbonate) but the MSRP is $140 (street price $90). Nikon makes two barrel-shaped monoculars, one with less magnification (5x) and the other with more (7x) and the same aperture that sell for over $300.
Observing Party	Charlie Ridgway Kin Lee

Target Jupiter Constellation Oph Category Planet Time yyyymmdd.hhmm 20070925.2120 EDT Comments Object Class Classical Planet Elongation 70.9° Distance Light Time (from Earth) 5.52 AU 45m57s Distance (from Sun) 5.28 AU Angular Size 35.6"x33.3" Magnitude -2.0 Central Meridian I/II 321°/346° Altitude 7.1° Moons Starry Night Starter graphic I set up on Jupiter since it was already low in the schmutz of the western horizon and would soon be setting behind the buildings. At 22x I was able to see one moon out to the west, probably Ganymede based solely on size, and Kin thought he might have seen Europe off to the East. At 42x we were not able to see any moons.

Target Moon Constellation Psc Category Lunar Time yyyymmdd.hhmm 20070925.2130 EDT Comments Lunation 1048 Phase Waxing Gibbous Full -17h18m Age 14d12h45m Distance Light Time (from earth) 360,009 km 1.2s Elongation 169.3° % Illuminated 99.1% Morning Terminator Colongitude (λ E) 83.3° Evening Terminator Colongitude (λ W) 263.3° Libration in Latitude -1°00’ Libration in Longitude -3°40’ Magnitude -12.6 Angular Size 33’17" Altitude 33.6° Virtual Moon Atlas graphic The Moon was so bright and the contrast so low that it was hard to see much. There is still lumpiness along the western limb and I was able to identify Montes Cordillera and Montes Rook (in Mare Orientale). I could see something on the limb further to the south but was not able to figure out what it was because the reference features were too washed out to allow for geometric location.

Target Algol Minimum Constellation Per Category Variable Star Time yyyymmdd.hhmm 20070925.2230 EDT Comments I set up on Algol, β Per. and ρ Per to watch Algol fade. I found that both stars were just visible in the 22x FoV being just inside opposite sides of the field stop. I have performed a drift test and determined the TFoV of the 20mm Omni when used in SAR to be 2.3°. Planetarium informs me that Algol and ρ Per are 2.2° apart. They are too far apart to see comfortably in the eyepiece and definitely too far apart to make a good relative brightness estimate. At times I felt that one was brighter and at times the other; most of the time they appeared about equal brightness naked-eye. At the beginning of the observation Algol appeared slightly brighter telescopically and the same was true by around 0030 EDT when I stopped observing to take a last look at the Moon before the sprinklers came on. Starry Night Starter graphic S&T recommends comparing Algol with γ Andromidae and ε Persei to get a brightness estimate. Star Magnitude Algol 2.1 - 3.4 γ And 2.1 ε Per 2.9 S&T article Algol is at its minimum brightness for about two hours so I observed it during that time and should have not detected much variation. Our next chances to see Algol go to minimum will be 15-16Oct07 (minimum at 16Oct07 @ 0112 EDT) and 18Oct07 (minimum at 2201 EDT) when we will have a chance to see it fade and brighten.