I think this comes from Seth Shostak, not Dr Norris.
> per hour. This would give it an orbital period of 180 hours. Therefore
The rate is lower bound on the angular rate and may or may not have been
corrected for the earth's rotation. It's a lower bound because it
depends on the direction of movement relative to the interferometer
baseline, and would only apply if the target was directly overhead,
which would not have been true if it was near the aim point.
> if Dr. Norris terminated this observation in less than 20 minutes , that
> would mean it only moved 1/3 of a degree before Norris made his
> conclusion, IF in fact it was moving across the beampath as he inferred.
> This inference was derived from the time it took for the source to
> modulate down in amplitude giving the impression that it was crossing
No it wasn't. Given the method that was actually used, the data present
on their web page, which was still online yesterday, would be sufficient
to compute the lower bound on the mean angular rate to better than 1%,
and even just looking at it on the screen, it is easy to get a figure to
better than 5%. Incidentally, I make the equivalent of your 180 hours
to be 122 hours (linear extrapolation in the frame of reference of the
My suspicion is that it is only possible to extract 4 of the required
6 parameters to define an orbit, with any great precision, from the data