Hayabusa 2 Earth Fly-by Dec 3rd

From: Richard Alan Keen via Seesat-l <seesat-l_at_satobs.org>
Date: Wed, 2 Dec 2015 04:41:02 +0000
Hayabusa 2 (spacecraft)
For tomorrow's flyby, using http://ssd.jpl.nasa.gov/horizons I get for my home near Golden, CO:
Date__(UT)__HR:MN     R.A._(ICRF/J2000.0)_DEC Azi_(a-appr)_Elev              delta    S-O-T
2015-Dec-03 01:00 A   16 51 59.68 +33 16 49.8 295.7136  21.9328   0.00121916468976  55.4267
The distance delta is in A.U., the time is 9 hours before closest approach to Earth.
As twilight ends Hayabus will be 22 degrees above the NW horizon, and sets about two hours later.
The question now is how bright will it be.  Back in 2005 I observed "Rosetta sliding through Leo" http://www.satobs.org/seesat/Mar-2005/0046.html as magnitude 11.4 at a distance of 0.0015076613 A.U., scarecely greater than Hayabusa will be tomorrow (Wednesday Dec. 2) evening.
Hayabusa's mass is about 1/3 that of Rosetta, so if the overall scale of the observed spacecraft (solar panels, bus, etc.) is also about 1/3, Hayabusa should be about 1 or 2 magnitudes fainter, or about magnitude 13.  Worth a try, but it won't be easy in the winter wind, cold, and blowing snow.

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Received on Tue Dec 01 2015 - 22:41:46 UTC

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