Chandra Observed Nearing Apogee

Ron Lee (
Thu, 30 Sep 1999 22:08:09 -0600

This mornings observation of Chandra encouraged me to try
at a more distant range.  This evening I had a possibility
at it approaches apogee.  After running a Skymap prediction
with confirmation from the JPL site, I set up the telescope.

Unfortunately I was a few minutes late with my primary star
location.   But on the good side a backup was withng the same
field of view.  After checking the time, I looked and saw a 
very slow moving object at the right place.

I was surprised that it was so easy to see.  Since I had missed
my preferred star to get a position I had to regroup and find
another location.  At  3:09:10 (h:m:s) UT on 1 Oct 99 I made a
position fix at RA 17:26.81 (, DEC +26:48.3 (dd:mm.m)
(J2000).  One of the stars in the triangle at that point does
not appear to be correct with my Guide printout so the position
might be less accurate than indicated.

At that point Chandra was at an altitude of about 114,169 km and
a range of 115,776 km.   Magnitude in the 12 range (+/- 0.5).
With a Skymap phase angle of 90, this equates to a standard
magnitude of about 1.5.   Averaging with my obs of this morning
yields a standard magnitude of 2.

This is probably a record distance observation for me and can 
be improved since I came in while it was still visible.  
Limiting magnitude about 13 tonight.

Ron Lee
104.5614 W, 38.9478 N, 2073 m