RE: tiangong 1

From: Ted Molczan (
Date: Sun Nov 27 2011 - 20:29:12 UTC

  • Next message: Russell Eberst: "2011NOV27.OBS Part II"

    Abdolreza Lavari wrote:
    > Hi every one
    > Tonight(2011.11.27 UTC 14:47:16)for the first time I saw TIANGONG1 in
    > time that was correctly predicted by heavensat.but I did not see
    > COSMOS 2428 with  mag 3.8 although sky was very clear. why?
    > My observing site: 28.9569 N  50.8504 E
    Cosmos 2428 (07029A / 31792) is a Tselina-2 electronic intelligence satellite. Rainer Kracht analyzed Russell Eberst's
    hundreds of observations of the first 16 satellites of this series, and found standard magnitude of 5.56 (1000 km, 90
    deg phase angle), with coefficient of phase ~0 (zero):
    Assuming that you attempted to observe the pass predicted near 15:07 UTC, then the maximum predicted brightness was mag
    6.0. Uncertainty of satellite brightness predictions is at least 1 or 2 magnitudes, so it could have reached between mag
    4 and 8, but was more likely to have been fainter than mag 5, than brighter; therefore, probably it was much fainter
    than you expected. I recommend checking the standard magnitude data in Heavensat.
    Ted Molczan
    Seesat-l mailing list

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