[amsat-bb] AO-51 Sighting...Possible Explaination

[Armando Mercado]

Hello All,

Last week, there was a flurry of postings about sighting
AO-51. The initial report was from Riverside, CA,
USA, 34.0 N 117.4 W, Elevation 250 meters.


After much checking, I believe what was actually seen
was an upper stage of Soyuz booster that launched
COSMOS 1184 on June 4, 1980.

In the original post, the observer reported the object
"directly overhead" at 6:10pm PST (0210 UTC 
06 November 2008).  The SL-3 rocket body 
was 80 degs high at 6:10:39pm PST.

AO-51 on the other hand was 83 degs high a
minute and a half later at 6:12pm PST, so the timing
is a better fit for the SL-3 R/B.  The SL-3 R/B is
about 12 ft. long and 8 ft. in diameter.  It orbits
about 140 miles lower than AO-51.

In the summer of 2006, I made a visual sighting of 
AO-7 using a 70mm "goto" telescope at 25 powers
of magnification  It took many tries, but finally on a
near perfect 88 deg pass I spotted it.  It was about
7th magnitude at is brightest and very tiny.

Since then I have made a couple of serious attempts
to spot AO-51 using 11x80 binoculars, and a 70mm
telescope and have not succeeded.  My next attempt
will be with my 8 inch telescope, but not until the
weather gets warmer.

>From my personal experience, I do not think AO-51
would be visible to a casual observer.  One must also
keep in mind AO-51 is in a polar sun synchronous orbit.
This is a very popular orbit for satellites to be launched
into and consequently there is a lot of stuff up there.

It's kind of like watching US-101 during the rush hour
and expecting to see a white car at  4:30 PM.  
You'll see one.

Enter the lat/long for  Riverside, CA, 
( 34.0  N 117.4 W, Elevation 250 meters), plug in the
follow keps, set your clock to 0200UTC, 06 NOV 2008,
and see what you think....

SL-3 R/B
1 11822U 80044B 08311.47990140 .00000945 00000-0 44143-4 0 1751
2 11822 081.2402 315.5175 0023019 261.6853 098.1731 15.18617526552470
AMSAT ECHO

1 28375U 04025K 08311.64072703 .00000014 00000-0 16651-4 0 2382

2 28375 098.0621 328.1455 0085038 080.2834 280.7950 14.40623296228910



73, Armando, N8IGJ