++ed by:
1 non-PAUSE user
Sergey Krushinsky
and 1 contributors

# 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. Algorithms 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>`