It seems you mean UTC+3 with summer time: Ir# Date Local Time Azm El Rng N SunEl M FlrAng Mag Max Flare Location 12 01- 3-27 21:02:22.6 126 55 926 D -15.5 R 0.44 -5.2 8.5 km West 16 01- 3-28 20:56:20.0 125 55 935 D -14.1 R 1.61 -1.0 29.2 km East 29 01- 3-26 5:20:49.0 012 10 2338 A -22.9 R 1.90 2.1 Does not intersect 33 01- 3-30 17:31:59.5 249 31 1327 D 25.3 R 0.01 -4.7 0.9 km West 36 01- 3-26 19:23:17.9 194 61 883 D 3.1 R 0.16 -8.0 2.8 km West 52 01- 3-29 20:50:15.0 125 54 941 D -12.8 R 3.50 1.6 63.5 km East 55 01- 3-25 5:35:02.0 009 16 1924 A -20.6 R 3.84 3.9 281 km West 60 01- 3-25 5:26:44.8 012 11 2282 A -22.1 R 0.67 -1.3 72.7 km West 84 01- 3-26 21:08:26.0 126 56 918 D -16.8 R 2.55 0.5 47.9 km West I have seen about ten daytime flares, but missed at least that many! Looking at the right spot is essential - use a compass, a spirit level and some navigation/drawing tool to check the elevation. Beware of camera+tripod affecting the compass! A better method is to locate the correct RA/Dec (5:47, +9.1) at night, e.g. the +4 mag star above beta CMi (7:28 +8.95) at 22:08 (summer time) on the 25th, if you can find a landmark and mark the tripod's place (or leave the tripod out all night+day!). (SkyMap plot of CMi + my photo attached to Anthony) I have photographed two daytime flares, one with a Maksutov type 250 mm telephoto lens. It was not focused correctly, so the satellite appears as a circle (the retro-reflector on the front corrector limits the aperture) This one I viewed at the same time. The other one was with a zoom, set to 85 mm. I pressed the shutter release at the second predicted, but didn't see it - but it appears as a dot on the picture! I took one as soon as possible after, and it doesn't show the dot. The exposure must be set to match the daylight sky (I used automatic exposure, but you may want to underexpose 1-2 steps) You don't need any tracking, since no stars are visible, and the satellite moves only a few meters to a km during the exposure! At night you may want tracking to get a more attractive star background, but don't track on the satellite - I would think you would like to show the rise and fall of brightness, and possibly even some irregularities, so the 300 mm gives too small a field at night. Almost any camera could capture a daytime flare, but at night you need a camera that can keep the shutter open for many seconds without vibrations (cable release). If the sky is dark, you should use at least 30-60 seconds for good star images/tracks. For satellite tracks with a fixed camera, the efficiency of a lens is focal length/(F stop squared), ie 250/5.6/5.6 = 8 for my reflector telephoto, 12.5 for a 50 mm/2.0 -- bjorn.gimle@tietotech.se (office) -- -- b_gimle@algonet.se (home) http://www.algonet.se/~b_gimle -- -- COSPAR 5919, MALMA, 59.2576 N, 18.6172 E, 23 m -- -- COSPAR 5918, HAMMARBY, 59.2985 N, 18.1045 E, 44 m -- > > > > As a final comment, can I assume that the length of exposure will > > be a function of magnitude? If so, I would love to see some feedback on > > exposure times (daylight and night time) as a function of magnitude. > > ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Sat Mar 24 2001 - 16:47:46 PST