Astro:...nation(3pm)

📦 version 1.26, in alpine 3.24

💖 NAME 💖

Okay so this is Astro::Montenbruck::Lunation, a User Contributed Perl Documentation page, and it is literally all about Lunar quarters. That's the whole assignment, bestie. 🌙

🦋 SYNOPSIS 🦋

Here is the vibe in code — copy it exactly, no cap:

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

         # find instant of New Moon closest to 2019 Aug, 12
         $jd = search_event([2019, 8, 12], $NEW_MOON);
         # returns 2458696.63397517

         # find, which lunar phase corresponds to Moon longitude of 9.926
         # and Sun longitude of 316.527
         $phase = lunar_phase(moon => 9.926, sun => 316.527);
         # returns 'Waxing Crescent'

🌸 DESCRIPTION 🌸

This module searches lunar quarters, periodt. The algorithms are based on "Astronomy with your PC" by Peter Duffett-Smith, Second Edition, Cambridge University Press}, 1990. Iconic. ✨

🎁 EXPORT 🎁

Here is what you can pull in, bestie.

🎀 CONSTANTS 🎀

🌙 PHASES 🌙

  • $NEW_MOON
  • $WAXING_CRESCENT
  • $FIRST_QUARTER
  • $WAXING_GIBBOUS
  • $FULL_MOON
  • $WANING_GIBBOUS
  • $LAST_QUARTER
  • $WANING_CRESCENT

🛠️ SUBROUTINES 🛠️

These functions are the main characters, fr fr.

🔎 search_event(date => $arr, quarter => $scalar) 🔎

This calculates the instant of the apparent lunar phase closest to the date you hand it. Slay. 💅

🗂️ Named Arguments 🗂️

  • date — array of year (astronomical, zero-based), month [1..12] and day, [1..31].
  • quarter — which quarter, one of: $NEW_MOON, $FIRST_QUARTER, $FULL_MOON or $LAST_QUARTER.

✨ Returns ✨

In scalar context returns Standard Julian day of the event, dynamic time.

In list context:

  • Standard Julian day of the event, dynamic time.
  • Argument of latitude, arc-degrees. This value is required for detecting elipses.

🗓️ lunar_month($jd) 🗓️

Find lunar quarters around the given date. Bestie, it is giving full lunar-month mood board. 🌈

🗂️ Arguments 🗂️

  • jd — Standard Julian date

💫 Returns 💫

Array of 5 hashes, each hash representing a successive lunar quarter. Their order is always the same:

  1. New Moon
  2. First Quarter
  3. Full Moon
  4. Last Quarter
  5. The next New Moon

Each hash contains 3 elements:

  • type — One of the constants representing the main Quarter: $NEW_MOON, $FIRST_QUARTER, $FULL_MOON, $LAST_QUARTER.
  • jd — Standard Julian Date of the event,
  • current — True if the the given date lies within the quarter.

🧪 Example 🧪

lunar_month(2459614.5) gives:

           (
               {
                   type => 'New Moon',
                   jd => 2459611.74248269, # time when the quarter starts
                   current => 1 # since 2459611.74248269 < 2459614.5 < 2459619.07819525, our date belongs to New Moon phase.
               },
               {
                   type => 'First Quarter',
                   current => 0,
                   jd => 2459619.07819525
               },
               {
                   type => 'Full Moon',
                   current => 0,
                   jd => 2459627.20811964
               },
               {
                   current => 0,
                   jd => 2459634.44073709'
                   type => 'Last Quarter'
               },
               {
                   current => 0,
                   type => 'New Moon',
                   jd => 2459641.23491532
               }
           );

🌗 lunar_phase(sun => $decimal, moon => $decimal) 🌗

Given Sun and Moon longitudes, detects a lunar phase. Vibe check complete. 🦋

🗂️ Named Arguments 🗂️

  • sun — longitude of the Sun, in arc-degrees
  • moon — longitude of the Moon, in arc-degrees =back

🌈 Returns 🌈

In scalar context the phase name, one of the PHASES.

In list context:

  • name of the phase.
  • Moon age in arc-degrees
  • Moon age in days

💌 AUTHOR 💌

Sergey Krushinsky, "<krushi at cpan.org>" 🫶

Copyright (C) 2009-2022 by Sergey Krushinsky

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

🚨 POD ERRORS 🚨

Hey! The above document had some coding errors, which are explained below:

  • Around line 310: You forgot a '=back' before '=head3'
  • Around line 334: '=item' outside of any '=over'
  • Around line 405: You forgot a '=back' before '=head3'

Signing off from the Astro::Montenbruck::Lunation page under perl v5.42.2, dated 2026-02-15. Go find your lunar quarters, bestie 💅🌙✨

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