RE: ISS bit dimmer than predicted

Ted Molczan (
Thu, 24 Jun 1999 10:50:44 -0400

Russell Eberst has pointed out an error in my reply to Mark Hanning-Lee on
20 Jun.

I gave the wrong magnitude for Arcturus. It is -0.06, NOT 0.2. As Russell
pointed out, knowing the correct magnitude of Arcturus actually strengthens
my conclusion. Here then, is my revised response to Mark:

Just prior to seeing your obs report, I used some of Russell Eberst's
observations to estimate ISS's std Mv, which I put at about 2.5 (1000 km,
half phase).

Using that value, I obtained a maximum brightness of 0.2 mag for the pass
you observed. Your report that it never quite reached the brightness of
Arcturus, -0.06 mag, seems well within the expected uncertainty, so you
might want to use std mag = 2.5.

Ted Molczan