22 September 2006

Observing Location	PSC
Observational Period	1000-1015 EDT
Atmospheric Conditions	Mostly cloudy. The clouds were of mixed varieties but mostly cirrus that the sun was visible through. It was a little cool with detectable humidity and no breeze. Thicker patches of cloud had to be worked around but the clouds were moving fast so I didn't have to wait long for them to pass but had to look fast to see through the thin patches which were moving equally as fast. There was no limb boiling and I would have termed the seeing excellent if it were not for the periods of poor seeing when the thicker clouds were present. Transparency Fair Seeing Good
Instruments	Canon 15x50 IS binocular w/Baader AstroSolar filter film - Charlie
Observing Party	Charlie Ridgway

Target Sunspots Constellation Vir Category Solar Time 20060922.1000 EDT Comments Heliphraphic Latitude (B0) +7.05° Heliographic Longitude (L0) 342.60° Position Angle (P) +25.15° Carrington rotation number (CR) 2048 There is still only one group visible. It was much easier to spot today but I dont know if that is an indicator of growth or is because the clouds are reducing the contrast. I will have to check Active Region Explorer and see what it says about the history of the group's size. I checked Active Region Explorer and it indicates a change in size of between -25% and +25% over the last 24 hours but it doesn't get any more specific than that. Group 910 Heliographic Latitude -12° Heliographic Longitude 355° McIntosh System Axx The group appears darker today and is slightly past the meridian.   Groups Spots R North 0 0 0 South 1 1 11 Total 1 1 11 R = (Groups * 10) + Spots)

Anticipating that I would be going to the Sun Triangle today with my camera I took it up to Metropolitan Oval last night when I got home from observing and made a few pictures of the conditions under which I observe there. This morning I went back there and made some daylight pictures of the area.

There are four poles which each have two giant flood lights on them that seem to shine in your eyes no matter where you stand around the oval. They appear here is blue-white lights. The regular area lights which appear salmon colored, are in a full cutoff fixture I think. But they are low enough, and close enough together, and bright enough that they are also bothersome.

Along the way I stopped off at PSC, where I do a lot of my local solar observing, and photographed that location as well.

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Observing Location	McGraw-Hill Building, Rockerfeller Center, Sixth Ave (formerly Avenue of the Americas, and previously Sixth Ave) @ 48 St, New York, NY
Observational Period	1115-1400 EDT
Atmospheric Conditions	Perfect, not a cloud overhead and only a very slight haze. Very comfortable temperature. By 1400 it was mostly cloudy and I had to wait for the sun to get pictures. Transparency Good Seeing
Instruments	Minolta X-700 SLR w/MD Zoom 35-70mm d 1:3.5 - Charlie
Observing Party	Charlie Ridgway Peter Tagatac

Target Constellation Category Solar Time 20060922.1115 EDT Comments The autumnal equinox is early tomorrow morning (0003 EDT) and tomorrow should be the day to see the sun align with the McGraw-Hill Sun Triangle. But I think today, setting aside the fact that it is supposed to be cloudy and may rain tomorrow, is the appropriate day to make the observation. The triangle is set up so that the sun aligns with one of its arms at noon on each solstice and equinox. But the triangle does not take into account Daylight Saving Time so the alignment, when Daylight Saving Time is in effect, actually occurs at 1300 EDT rather then at noon. The equinox will occur tomorrow at 0003 EDT, 11h3m after 1300. But from the equinox until 1300 of that day is 12h57m. So I believe the best alignment will occur today rather than on the calendar day of the equinox. Unfortunately tomorrow's weather is unlikely to allow me to fully test this theory. I am also interested to see if the alignment occurs four minutes before the appointed hour, as I believe it does, because NYC is at roughly Long -74° while the central meridian for our time zone is at Long -75°. That means that noon by the sun occurs four minutes earlier than noon by the clock. I think this test would best be done on the date when a solstice or equinox occurs exactly at noon EDT. A small group of people gathered shortly before noon and left then a larger group materialized as the event was unfolding. Time 1115 EDT 1130 EDT 1145 EDT 1200 EDT 1215 EDT 1230 EDT 1245 EDT 1247 EDT ~1300 EDT 1315 EDT 1330 EDT 1345 EDT The event took place earlier than anyone expected even taking into account our displacement from the central meridian. I estimated it at 1247 EDT and Peter thought 1251 EDT. No one has an explanation for the time difference. Some people who had planned to arrive at the last moment arrived after the moment had come and gone because of this. [We never compared our watches to see how much they differed. My watch is 50 seconds behind my PDAs which are set to my computer clock which IV in turn set to an NIST time server. Peter has his watch set to eBay time.]

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At the Channel Garden in Rockefeller Center there is a giant sculpture composed of an aluminum parabolic disk that is mirror polished on both sides. It is 30 feet across and about a foot thick and is composed of a central disk about 5-10 feet across and then wedge segments surrounding it. The concave side points up to the west at the sky and buildings which you see upside down on the mirror surface. The convex side points to the east and down at the ground where you can see yourself and your street level surroundings. Kin has suggested we take our eyepieces and turn it into a giant telescope primary. I wonder how far away you would have to out the secondary to get it in the focal plane of a 10 meter mirror. It would probably be far enough away that you could stand there with your eyepiece and be a smaller central obstruction than the secondary mirror. The mirror segments are not critically aligned enough to use it as a telescope mirror and they are not flat enough either. You can see where the image of the buildings does not line up as it crosses panel seams. I wonder if the mirror reflects light through the windows of any of the buildings and causes problems for them or similarly for cars passing by on the street in the morning. And what does it look like to passing planes and does it cause any problems for the pilots.
Since this is a mirror you can find me in many of the pictures; I'm wearing a yellow jacket and am one of the few people who still has to hold my camera to my eye to make pictures (it is a real film camera).

Tumi page on the Sky Mirror

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Tonight was supposed to be the first public observing session from the rooftop Rutherford Observatory on Pipin Hall, Columbia University, but they have rescheduled the event for next week hoping for a better sky.

It also looks like it will be too cloudy to get the first crescent Moon of lunation 1036 tomorrow evening.