Moon Declination & More [BlueprintResearch]

🌒 MOON DECLINATION & MORE

A comprehensive lunar declination visualization showing Moon, Sun, and node declinations, with phase coloring, zodiac sign tracking, and future projections.

Part of the Blueprint Research open-source ephemeris project.



█ WHAT'S INCLUDED

• Moon Declination — The Moon's angular distance from the celestial equator, oscillating rapidly (~27 days)
• Sun Declination — Optional overlay showing the Sun's seasonal declination (±23.4°)
• Node Declinations — North (☊) and South (☋) node lines forming the Moon's orbital envelope
• Future Projections — Project all lines up to 500 bars into the future
• Zodiac Crossing Markers — Indicates when the North Node reaches a particular zodiac degree. Keep in mind, nodes move through the zodiac in reverse.



█ CONCEPTS

Declination measures how far north or south a celestial body appears from the celestial equator. The Moon's declination oscillates rapidly, while its maximum range shifts slowly over the 18.6-year nodal cycle.

Node Declination Envelope:
The North (☊) and South (☋) node lines mark the envelope of the Moon's orbit—the theoretical maximum northern and southern declinations the Moon can reach.

Lunar Standstills:
The 18.6-year nodal cycle determines when the Moon reaches its most extreme declinations. During a major standstill, the Moon can exceed ±28° declination. During a minor standstill, the Moon's range is limited to approximately ±18°.

Out-of-Bounds (OOB):
When the Moon moves beyond ±23.44° declination, it exceeds the Sun's maximum reach and is considered "Out of Bounds."



█ COLORING OPTIONS

Phase Coloring (Moon)
Color the Moon's declination line by lunar phase:
• New Moon (0-90°): Slate silver
• First Quarter (90-180°): Mint
• Full Moon (180-270°): Bright gold
• Last Quarter (270-360°): Soft violet

Zodiac Sign Coloring (Nodes)
Color the node lines by their zodiac sign. When enabled, a color legend appears at the top, showing all 12 signs for reference.



█ ZODIAC FEATURES

Zodiac Sign Coloring
Color the North and South Node lines according to their zodiac sign positions.

Zodiac Crossing
Marks when the North Node crosses a specific zodiac degree. Select any sign and degree (0-29) to track. The North Node moves retrograde through the zodiac over an 18.6-year cycle.



█ RESEARCH FEATURES

Standstill Thresholds
Horizontal reference lines at key declination levels:
• ±28.6° Major Standstill (peak of the 18.6-year cycle)
• ±18.3° Minor Standstill (trough of the cycle)
• ±23.4° Out-of-Bounds threshold

OOB Highlighting
Optional background shading when the Moon exceeds the OOB threshold.

Node Equatorial Crossings
Crosshair markers indicate when the node's declination crosses 0° (equatorial passage).

Reference Line Labels
Labels at projection endpoints with an adjustable offset for readability.


█ FEATURES


• Moon declination with optional lunar phase coloring
• Sun declination overlay
• North and South node declinations (☊ and ☋)
• Future projections up to 500 bars
• Zodiac sign coloring with a color legend
• Zodiac degree-crossing markers
• Node equatorial-crossing markers
• Out-of-Bounds background highlighting
• Reference line labels with offset control
• Customizable line widths and colors
• Informative tooltips for all settings
• Works on all timeframes



█ HOW TO USE

1 — Add the indicator to your chart
2 — Configure which elements to display (Moon, Sun, Nodes)
3 — Enable future projections to view upcoming declination values
4 — Enable Zodiac coloring to track node sign positions
5 — Set a Zodiac Crossing degree to mark when the North Node crosses that point
6 — Enable Standstill Thresholds to show reference lines
7 — Toggle phase coloring to visualize the lunar cycle



█ THEORY

Lunar Theory: ELP2000-82 by Chapront-Touzé & Chapront
Solar Theory: VSOP87 for Sun position and phase calculation
Reference: Meeus, "Astronomical Algorithms" (2nd Ed., 1998)


█ LIMITATIONS

• Truncated ELP2000-82 theory (~10 arcseconds precision)
• Future projections assume consistent bar timing
• Phase coloring uses 4 phases (not the 8 traditional phases)
• Mean nodes only (no perturbation corrections)


█ OPEN SOURCE

Blueprint Research Ephemeris Libraries:
• lib_elp2000_moon — Lunar position and mean node calculations
• lib_vsop_core — Solar position and coordinate utilities
• lib_ephemeris — Unified planetary API

Third-Party Libraries:
• hsvColor by kaigouthro — HSV color utilities (MPL 2.0)


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