Anderlič-Firneis criteria

for the

First Lunar Crescent

Uroš Anderlič

 

Maria G. Firneis as well as me used a semi empirical method for the determination of the first lunar crescents and constructed special solutions for the program package Uraniastar, which has been used for the calculations. The method is mainly based on the age of the moon, the illuminated fraction of the moon, the topocentric apparent geometrical altitude of the moon at the beginning of civil twilight, and the topocentric apparent geometrical altitude of the moon at the end of civil twilight. The Anderlič-Firneis criteria are summarized in the following table:

Text Box:   ANDERLIČ-FIRNEIS Boundaries Extreme Boundaries CRITERIA Minimum value Maximum value Minimum value Maximum value Illuminated fraction 0.01 0.03 0.01 0.11 Age [days] 0.6 1.9 0.5 3.1 Altitude (Beginning) [º] 5.79 20.48 5.79 20.48 Altitude (End) [º] 1.90 15.65 1.90 15.65  

First lunar crescents show a moon’s illuminated fraction between the boundaries 0.01 and 0.03, and a moon’s age between the boundaries 0.6 days and 1.9 days with some exceptions that outrange these limits.

 

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