Spherical astronomy, ecliptic longitude, and the art of the wheel
A natal chart is simply a photograph of the sky taken from a single point on Earth at a single moment. Soleilx draws that photograph as a 360-degree SVG wheel so you can see how planets, signs, and houses relate to one another at a glance. The wheel begins with the ecliptic, the apparent yearly path the Sun traces against the fixed stars. Because the Earth is tilted on its axis, the ecliptic is inclined about 23.4 degrees to the celestial equator, and every planetary body in our solar system travels within a few degrees of this plane. Ecliptic longitude measures position along that path, beginning at 0 degrees of the vernal point and increasing eastward through the twelve signs.
Our calculator relies on the open-source astronomy-engine library, released under the MIT license, together with the classic algorithms published by Jean Meeus in Astronomical Algorithms. These routines convert civil date and time into Julian Day, then into geocentric ecliptic longitude for the Sun, Moon, and major planets. The result is a set of accurate tropical longitudes that reflect where each body actually sits in the zodiac, not a preset list of pop-astrology keywords. We also compute the Local Sidereal Time for the birth longitude, which tells us which part of the star field was crossing the meridian at that instant.
From sidereal time and latitude we derive the Ascendant, the degree of the ecliptic rising on the eastern horizon, and the Midheaven, the degree near the top of the sky. Soleilx uses Whole-Sign houses, one of the oldest house systems in the tradition: the sign containing the Ascendant becomes the First House, the next sign becomes the Second House, and so on through the zodiac. This keeps the geometry clean and highlights sign-to-house relationships without inventing artificial cusp boundaries. Each planet is then placed in the house whose sign it currently occupies, creating a readable map of personal and transpersonal themes.
We present the chart as an aesthetic and contemplative tool, not a predictive oracle. The wheel, the Big Three cards, and the DO / DON'T rhythm prompts are designed to invite reflection on temperament, timing, and creative energy. They echo Jung’s observation that mythic images resonate because they mirror inner structures of the psyche. Soleilx does not claim to forecast lottery numbers, medical outcomes, or romantic destinies; instead, it offers a structured way to look at the same sky poets and painters have watched for millennia. Use the wheel as a sketch, a journal prompt, or a compositional aid for your own art notes.
The daily studio summary synthesizes the Sun sign, Moon sign, rising sign, and current Ptolemaic aspects into short prose chips and editorial advice. These are curated from symbolic patterns, not deterministic rules. If a square suggests friction, we frame it as a question: where is the tension asking you to refine your work? If a trine suggests flow, we ask how you might share that generosity without overextending. The goal is always the same: to turn celestial geometry into a quiet, useful mirror for the day.