Solar Arc Directions for a target date. The solar arc (progressed Sun minus natal Sun) is applied uniformly to every natal planet and angle — approximately 1° per year. Unlike secondary progressions, all planets advance at the same rate.
SECTION: WHAT THIS TOOL COVERS
Solar arc directions — one delta longitude applied to every natal body and the angles. Classic predictive technique for timing outer events.
SECTION: WORKFLOW
BEFORE: asterwise_get_western_natal.
AFTER: None.
SECTION: INPUT CONTRACT
birth — WesternBirthData.
target_date (optional YYYY-MM-DD) — defaults to today.
SECTION: OUTPUT CONTRACT
data.target_date, data.solar_arc, data.age_years
data.natal_sun_longitude, data.progressed_sun_longitude
data.directed_planets[] — 10 objects: name, natal_longitude, directed_longitude, sign, degree_in_sign, dignity, dignity_score
data.directed_ascendant, data.directed_ascendant_sign
data.directed_mc, data.directed_mc_sign
SECTION: RESPONSE FORMAT
response_format=json serialises the complete response as indented JSON.
response_format=markdown renders the same data as a human-readable report.
Both modes return identical underlying data.
SECTION: COMPUTE CLASS
MEDIUM_COMPUTE (~400ms)
SECTION: ERROR CONTRACT
INVALID_PARAMS (local): WesternBirthData validation failures.
INTERNAL_ERROR: Any upstream API failure or timeout → MCP INTERNAL_ERROR
Edge cases:
All planets advance at the same rate (solar arc ≈ 1°/year). This is Solar Arc Directions — different from secondary progressions where each planet moves at its own astronomical speed.
SECTION: DO NOT CONFUSE WITH
asterwise_get_western_secondary_progressions — each planet moves at its own rate.
asterwise_get_western_transits_daily — real-time transits, not arc directions.
Connector