A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Ritchie
Date: 2022 Jan 8, 13:29 -0800
Thank you, Peter, for identifying the occulting star as HD 202635. I fed its Simbad J2000 coordinates and proper motions to Astron's custom star utility and 'adjusted' the time to achieve a near limb sextant arc of zero. My result for the time of occultation was 01:11:47 for an altitude of 1450m.
I then looked at the adjacent star near 12 o'clock and one fifth of a Moon radius from the limb (HD 202672). It is an optical double and Fred's wonderful image shows the companion faintly. Pixel scaling gave a distance of 2.84' from the near limb and a time of 01:11:40. I used the near (shutter closing) end of the (30 second exposure?) star trace.
The screenshot attached is of the first result. I would put more weight on that as it does not involve scaling.
Sorry to be a late entrant for this quiz - I am in the middle of changing my Moon calculation method from using Jan Meeus' 60 most significant terms of the ELP-2000/82 theory to the 577 most significant terms of the ELP/MPP02 lunar laser radar theory. I used the latter for the above results, which are about four seconds earlier than those given by the present release version.