> Subject: Cosmos 1220 - FYI > Date: Fri, 18 May 2001 10:50:50 -0700 (MST) > From: Rik Hill <rhill@LPL.Arizona.EDU> > To: SeeSat-L@blackadder.lmsal.com > > Last night I happened to be out just after 8pm here in Tucson. Overhead > was a bright satellite, about 0-1st mag. as I was able to compare it to > Arcturus (0 mag.). I went in and downloaded the Heavens-Above ephem. > for the evening and found that what I must have seen was Cosmos 1220. > The time, direction etc. were all correct but it was about 3 mags. off > in brightness! > > Any thoughts on this? Hi Rik, Join the club. This is something which I also have observed (excuse the pun) with a trend by H-A to underestimate magnitude. I had yet another example of this just the other night with an Iridium flare. To make matters worse, a flare a few minutes later by another Iridium satellite (-6.4 magnitude!) was completely missed by H-A but nicely picked up by Rob Matson's IRIDFLAR. For the latter satellite, it was just coming out of the earth's shadow but there certainly was lots of visible time after that anyway to make it a definite reportable pass. At this point I simply use H-A to get a general picture of what may be available and then proceed with Rob's SKYMAP and/or IRIDFLAR to confirm and fine-tune. Anthony. > > > -Rik ----------------------------------------------------------------- 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
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