NAME

Astro::Montenbruck::SolEqu - Solstices and Equinoxes.

SYNOPSIS

  use Astro::Montenbruck::SolEqu qw/:all/;

  # find solstices and equinoxes for year 2020
  for my $event (@SOLEQU_EVENTS) 
  {
      my $jd = solequ(2020, $event);
      # ...
  }

DESCRIPTION

The times of he equinoxes and solstices are the instants when the apparent longiude of the Sun is a multiple of 90 degrees.

Searches solstices and eqinoxes. Algorythms are based on "Astronomical Formulae for Calculators" by Jean Meeus, Forth Edition, Willmann-Bell, Inc., 1988.

EXPORT

CONSTANTS

EVENTS

• $MARCH_EQUINOX

• $JUNE_SOLSTICE

• $SEPTEMBER_EQUINOX

• $DECEMBER_SOLSTICE

ARRAY OF THE EVENTS

• @SOLEQU_EVENTS

Array of EVENTS in proper order.

SUBROUTINES

solequ

Find Julian Day of solstice or equinox for a given year.

    use Astro::Montenbruck::SolEqu qw/:all/;

        my $jd = Astro::Montenbruck::Ephemeris::Sun->solequ($year, $k);

The result is accurate within 5 minutes of Universal Time.

Arguments

1. number of a year (negative for B.C., astronomical)

2. type of event, defined by the constants (see Events).

Result

In scalar context retuns Standard Julian Day. In list context: array of:

1. Standard Julian Day and Sun's longitude, in arc-dgrees.

2. Sun's longitude, arc-dgrees.

AUTHOR

Sergey Krushinsky, <krushi at cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2009-2021 by Sergey Krushinsky

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.