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Validity of HO249 Vol. 1
From: Philippe Posth
Date: 2023 Feb 17, 07:10 -0800
From: Philippe Posth
Date: 2023 Feb 17, 07:10 -0800
Hello,
Table 1 of HO249 has a limited validity of 10 years. For example, the currently available edition, "Epoch 2025", is usable from 2021 to 2029 inclusive. I wonder what is the reason and level of this limitation. Is it motivated by:
1 - the limits of table 4 included in each edition and which only allows the calculation of GHA Aries for this period;
2 - the complete table itself in which the stars positions calculations would only be valid for this period.
In other words, what is the risk in terms of inaccurate results of using an outdated HO249 Vol.1 table when calculating GHA Aries using a valid Nautical Almanac.
Thank you for your answers.
