Brad Young posted: >Ed, can you or Mike check my positions and see if that was indeed LES 8? Yes, your positions match the predicted position for LES 8 very well. >Timings(UT) 2:09:16 2:11:14 2:13:11 >First 3 observations 1X (naked eye) then switched to 10X50 binoculars. Ed told me that the time of maximum brightness last night was about 1:58 UT here in Austin last night. My conclusion is that the flashes are generally northwest/southeast in direction and the flashes will move northeast over time. So the fact that you are 400 miles north and a little east of us would explain the fact that you observed flashes 12 or 14 minutes later than Ed did. >Magnitude (approx) +2.5 gradually declining to +7 on last one, except >"secondary flash" was also ~+7 mag. We failed to see secondary flashes a week ago and so we have not looked for them since then. >and I'll try again tonight, earlier again to suit. I believe the brightest flashes occur about 12 minutes earlier each night. LES 8 is very nearly geostationary (but with an inclination of 10 degrees). So it is in almost the same position at the same time every night. But the sun is currently moving south about 0.4 degrees per day. So the reflections move north about 0.4 degrees every day. At latitude 30 degrees, this corresponds to about 190 miles. So if we observe it to be brightest about 12 minutes sooner every night, the reflections must be 12 minutes later about 190 miles to our north that same night. (This assumes that the flash track is east/west.) (There is also some effect from the satellite moving north/south, but it is currently being observed near the northernmost point in its orbit.) An analysis of the times of maximum brightness as seen from Austin from 9/8 to 9/20 indicate that the "normal" to the reflecting surface was going from RA 10Hr 17Mn, Dec +1.0 on 9/8 to RA 9Hr 27Mn, Dec -2.9 on 9/20. This means that the spot of light across the Earth will move in a westnorthwest/eastsoutheast direction. The predicted time of maximum brightness is about 1:46 UT tonight for Austin. Observers north of Austin would see maximum brightness about 2 minutes later for each degree north. South of Austin would be 2 minutes earlier for each degree south (of latitude 30). Observers east of Austin (longitude 98) would see maximum brightness about 1 minute later for each 1 degree east of Austin. Observers west of Austin would be 1 minute earlier for each 1 degree west. Mike McCants Austin, TX ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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