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Re: Occultations of stars by the Moon
From: Geoff Hitchcox
Date: 2023 Oct 20, 17:00 -0700
From: Geoff Hitchcox
Date: 2023 Oct 20, 17:00 -0700
Bonjour Kermit,
You wrote
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Maybe one last request then if you do not mind ...
Would you be so kind as to process the "other" Lunar by Donald B. Prentice.
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No problem Kermit, but if you want a highly accurate and TRUE Horoscope - that will cost you a King's Ransom ;-)
If we 'copy and paste' the following line into the online Swiss Ephemeris , into the box called "other options"
-ejpl -occult -pf -b01.01.1924 -local -xfRegulus -geopos-71.399794,41.837667,69
we get:
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geo. long -71.399794, lat 41.837667, alt 69.000000
total(sunrise) 23.10.1924 11:34:49.7 1.000000 2424081.982520
73 min 27.95 sec 10:58:23.5 10:58:23.5 12:11:51.5 12:11:51.5 dt=23.7
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Now this to me is fascinating:
10:58:23.5 = Swiss Ephemeris (from above)
10:58:23.0 = Actual timed measurement by Donald B. Prentice (in 1924), who said "I believe this is within 3/4" of being correct".
I think the *Gold Standard* for Occultation predictions today would be Dave Herald's OCCULT (Windows based software) which although FREE and very comprehensive - is Windows only, and uses a Microsoft Library. Whereas I assume SWE is treating "Lady Moon" as a perfect sphere - rather than considering actual Lunar topography.
The above measurement by Mr Prentice is amazing Kermit - considering how close this was to Sunrise.
I also did not realise that 'JPL Horizons' and the 'Nautical Almanac' use a slightly 'different reference ecliptic', as mentioned here:
The Swiss Ephemeris Compared with Astronomical Almanac and JPL Horizons
Regards, Geoff Hitchcox, Christchurch, New Zealand.
