[meteorite-list] 10.04.14 AZ Daytime Fireball: Direct compass measurements
From: Steve Schoner <schoner_at_meteoritecentral.com>
Date: Sat, 11 Oct 2014 20:20:57 GMT Message-ID: <20141011.142057.6586.0_at_webmail01.dca.untd.com> Hello, all, Being that my all sky camera was damaged by lightning in July and replaced in August, and being that it did capture the image of this event near a prominent tree, I went up on the roof for direct measurements with two of my British WWII prismatic compasses. Keep in mind my node6 camera is aligned to the North Celestial Pole (North Star). The north star is a Cepheid variable, and unless it brightens to mag 2 it is very difficult to see with the All Sky camera. It's position is 10.5 degrees to the wast of the magnetic pole. Yesterday at Bellemont Weather Station right under and in line with the camera that took shots of the smoke clouds,I determined that they were at between 35 and 36 degrees magnetic readings. These reading are as close as I can determine as to the position of the clouds that day; 5 to 6 min later. But these smoke clouds might have drifted to the east in those five min and the degree readings would then be off maybe a degree or more depending on the wind speed 15 to 60 miles up. Bellemont Weather Station: Average 35.5 degrees NE add 10.5 degrees for Celestial Pole, making it 45.5 degrees NE from Celestial North. With respect to my "node6" rooftop camera, I studied the image captured and though the fireball image is small it traveled down to the right side of a pine tree on the shaded side. So with my compass in hand and taking measurements of where I think it vanished above or behind the tree I came out with 32-33 degrees NE. Flagstaff node6 All Sky Camera: Average 32.5 degrees NE add 10.5 degrees for Celestial Pole, making it 43 degrees NE. Estimated elevation above the horizon of burnout (terminal burst) from both locations determined with Bendix A-7 Bubble Sextant: -13 degrees at Bellemont. Estimated from the larger and higher elevation smoke cloud (terminal burst). The lower one measured at 7.25 degrees above horizon was the furthest away the fireball entry point. and at a much higher altitude in the smoke train. ~15 degrees at Flagstaff. Such elevations above horizon considering the lowest burnout at 15 miles would place the fireball termination no closer than about 75 miles North East of Flagstaff and Bellemont. If it ended at 20 miles or higher, then even farther away. That stated, it ended out in the middle of the Din`e(Navajo) and or Hopi Reservations. Please be mindful that for all intents on reservation lands you are on Sovereign Nation grounds, almost like stepping into another county. If you do some searching out there get permission first. Steve Schoner BTW: Now I need to get back to work and make some petrographic slides. ____________________________________________________________ NetZero now offers 4G mobile broadband. Sign up now. http://www.netzero.net/?refcd=NZINTISP0512T4GOUT1 Received on Sat 11 Oct 2014 04:20:57 PM PDT |
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