all things vedic · v4.70.1

The Astronomy under the Astrology

Nine foundations from Vikram's class — the science under the symbolism. Sourced from his decks and transcripts; nothing borrowed from elsewhere. Astronomy and astrology are intertwined — the chart is the visible sky, slowed down enough to study.

§ One

The Geocentric View · what the eye can see

From the class · Session 18 · Retreat Debrief, Parashurama & Stellarium

"We have the geocentric view. And because the earth is tilted, the equator is going to be tilted. And this is a projection of the equator — so it is the celestial equator. The earth is going around the sun like that, and this is known as the ecliptic. The two are tilted. They are at an angle. There will be two points where they are intersecting…"

Vikram, Session 18 · whiteboarding the geocentric frame live in class

Before any of the next eight sections can land, this one has to. Vedic astrology takes the position of an observer standing on this earth as the centre of its sky. The Sun rises in the east, climbs to its highest point overhead, descends, and sets in the west — and the planets and stars do the same, each on its own clock. Nothing in the chart is calculated from a heliocentric (Sun-centred) frame. The chart is the sky as you would see it from the spot where you were born, at the moment you were born.

This is also why Vikram keeps returning to the visible sky in class. The Mars-Jupiter asteroid belt, the Moon's quick orbit, Mercury's wobble — every meaning in the planet chapters is rooted in something an observer could in principle see. Vedic astrology is not abstract. It is what the eye can see, slowed down enough to study.

Astronomy and astrology are intertwined

The next eight sections walk through the structures Vikram uses in class — solar system, ecliptic, coordinate systems, celestial equator, eclipses, retrograde motions, precession, and the Stellarium lab. Each one of these is an astronomy concept first. The astrology grows out of it. If a section feels arbitrary, the chances are the geocentric frame underneath it has not yet clicked — come back here and re-read.

The four anchor points the chart actually uses

Whatever house system you cast a chart in (Whole Sign, Equal House, Sripati, KP), it begins from four points on the visible sky:

Three words people regularly mix up

M.C. is the highest point of the ecliptic. Zenith is the highest point of the sky for that observer. They are equal only at the equator.

↗ Want to see all of this on your own chart? Jump straight to the Stellarium Lab in § Nine below — it walks you through opening deva.guru and Stellarium side by side so the chart and the sky reveal themselves as the same thing.
§ Two

The Earth in the Solar System

From the class

The Sun is the source of all light and energy — the largest, mightiest body. It holds everything in its rightful place. Around it, the Earth takes 365 days to complete 360 degrees.

Vikram, Deck 10 · Solar System  ·  Session 5

The seven visible navagrahas orbit the Sun — Mercury, Venus, Mars, Jupiter, Saturn, plus the Moon (orbiting Earth) and the Sun itself. Together with the lunar nodes Rahu and Ketu, these are the nine grahas of Vedic astrology.

From the deck: each planet has a physical fact, and Vikram pairs each with its astrological meaning — Mars red in colour → anger, blood, fire. Saturn slowest moving → karaka of time. Moon closest to Earth → ruler of the senses. The astrology is built on what the sky actually does.

Sun Mercury Venus Earth (us) Mars Jupiter Saturn
Schematic — relative orbits, not to scale.

Cosmic scale exercise from the deck. If the Moon were a grain of sand, Earth would be a pinhead 2 cm away. The Sun would be a pool ball 6 metres away. Alpha Centauri — the nearest star — would be another pool ball 1,500 km from us. The Milky Way galaxy at that scale is the size of Mercury's orbit. The known universe is four football fields, holding 100+ billion galaxies.

↗ See the per-planet "From the sky" mappings inside §5 Planets in Learning Companion — tap any planet card.
§ Three

The Ecliptic & the Zodiac

From the class · Session 13

The path that the Sun takes along the Earth — that is the ecliptic. The ecliptic is a very important concept for us. We will be using this a lot, so I want to stay here a little bit, make sure that everybody is understanding this.

Vikram, Session 13 · Celestial Equator & Mahalakshmi

Earth orbits the Sun in a flat plane — the ecliptic plane. From Earth's point of view, the Sun appears to trace a great circle through the sky over the course of a year. That circle is the ecliptic.

A circle has 360 degrees. Each degree has 60 arc-minutes; each arc-minute has 60 arc-seconds. The deck quotes Rigveda 1.164.48: "Twelve spokes, one wheel, navels three. … three hundred and sixty like pegs." The Vedic resonance with 360° is direct.

The 360° ecliptic is divided into twelve 30° slices — the rāśis, the zodiac signs. Each rāśi holds 2¼ nakshatras. The wheel of signs in your chart is this same ecliptic, laid flat.

Earth 90° 180° 270° Sun (today) the ecliptic — 360° divided by 12
The Sun moves all the way around the ring across one year — about 1° per day.
↗ Where this lands — §1 Signs in Learning Companion shows the same wheel as the Rāśi Chakra.
§ Four

Coordinate Systems — locating a graha in the sky

From the class · Sessions 11 & 14

Pre-software, astrologers literally looked up at the sky to locate the navagrahas. Get the birth details, open Stellarium, find each graha, note the azimuth and altitude. Step outside; face that direction; be still; look, feel, notice — recognise this is where the graha was at birth.

Vikram, Deck 22 · Your Sky at Birth

There are two coordinate systems. Az/Alt is the local view from where you stand. RA/Dec is the universal celestial view, fixed against the stars.

Azimuth — the angle measured along the horizon, starting at North (0°) and turning clockwise: East 90°, South 180°, West 270°. Altitude — the angle from the horizon (0°) up to the zenith (90°). Each celestial object has its own (azimuth, altitude) pair from your specific location.

Right Ascension (RA) — celestial longitude, measured in hours rather than degrees. 24 hours wraps the sky: 1 hour = 15°. Declination (Dec) — celestial latitude, in degrees north (+) or south (−) of the celestial equator. Because RA/Dec are fixed to the stars, two observers anywhere on Earth give the same RA/Dec for the same star. Az/Alt depend on you.

horizon (alt = 0°) zenith (90°) a graha altitude azimuth N S Az / Alt — local view celestial equator N pole (+90°) S pole (−90°) RA / Dec — universal view
Az/Alt depends on where you stand. RA/Dec is fixed against the stars.

The Az/Alt exercise (Deck 22 · Your Sky at Birth) is about embodied astronomy: hold the chart in your hand, then walk outside, face the actual direction, and feel where each graha was at the moment you were born. This is the foundation transits later build on.

↗ Mentioned briefly in §1 Signs and used implicitly in §10 House Systems.
§ Five

The Celestial Equator

From the class · Session 13

The celestial equator is the projection of Earth's equator onto the sky. The Earth's axis is tilted about 23½ degrees, so the celestial equator is tilted 23½ degrees from the ecliptic.

Vikram, Deck 24 · Celestial Equator

If you imagine extending Earth's equator outward into space, where it intersects the sky is the celestial equator — a great circle running east-west around us. This is one of the two great circles that matter in astrology. The other is the ecliptic (the Sun's path).

The two circles are not the same. They cross at an angle of about 23½° — Earth's axial tilt. The two intersection points are the equinoxes: vernal (around March 20) and autumnal (around September 23). At an equinox, day and night are equal length everywhere on Earth.

celestial equator ecliptic — Sun's path vernal equinox autumnal equinox tilted ~23½°
Two great circles in the sky — they meet only at the equinoxes.

Why this matters astronomically: the Sun's apparent path (the ecliptic) cuts the celestial equator at the equinoxes. That's why the equinoxes mark the start of spring and autumn. The same tilt drives all seasons.

↗ Sets up §7 Precession, where the ecliptic-equator intersection slowly drifts — the basis of ayanamsha.
§ Six

Eclipses & the Lunar Nodes

From the class · Sessions 14 & 19

For an eclipse to happen, two conditions must hold. The Sun and the Moon need to be on the same axis — same RA. And their declinations need to match Rahu and Ketu — the lunar nodes.

Vikram, Sessions 14 & 19 · the Moon's orbit

The Moon's orbit around the Earth is tilted about 5° from the ecliptic. The two points where the Moon's orbit crosses the ecliptic are the lunar nodes: Rahu (the ascending node) and Ketu (the descending node). They're not physical bodies — they're geometric points. But astrologically, they carry weight.

An eclipse needs both conditions:

Without the second condition, the Moon passes above or below the Sun and no eclipse happens. With both, the shadow falls.

Earth ecliptic Moon's orbit (tilted ~5°) Rahu Ketu eclipse = Sun + Moon align on a node
Rahu and Ketu — the two points where Moon's orbit crosses the ecliptic.

Rahu and Ketu are always exactly opposite each other (180° apart) — the same axis, two ends. The nodes shift backwards along the ecliptic about 19° per year (a full circle in ~18.6 years). That's why eclipses don't happen every full and new moon, but only when the Sun and Moon catch up to a node.

↗ Rahu and Ketu's astrological treatment lives in §5 Planets and §4 Cabinet ("the Outsiders").
§ Seven

Apparent Motions & Retrograde

From the class · Deck 47 / BPHS 29.21–23

BPHS lists eight apparent motions of the planets: Sama, Manda, Mandotar, Vikala, Vakra, Char, Atichar, Anuvakra. Vakra is retrograde — when a planet appears to move backwards. Vikala is stationary. The others describe degrees of speed.

Vikram, Deck 47 · Apparent Motions

From Earth, the planets don't always move forward through the zodiac at a constant rate. They speed up, slow down, stop, and even appear to reverse direction. Brihat Parashara Hora Shastra catalogues eight states:

Retrograde isn't the planet actually reversing in space. It's an apparent motion — caused by Earth overtaking a slower outer planet, or being lapped by a faster inner one. The apparent loop is real, even though no actual reversal happens. In the chart, retrograde planets are read with extra care.

retrograde loop (vakra) direct (sama) slowing (manda) stationary (vikala) resumes direct
A planet traces this loop against the stars across the months of retrograde.
↗ The Apparent Motions deck (Deck 47) sits behind the retrograde commentary you'll see in §5 Planets over time.
§ Eight

Ayanamsha & Precession

From the class · Session 17

The vernal equinox marks the "First Point of Aries" — 0°. But the Earth wobbles. The intersection of the ecliptic and the celestial equator drifts backwards through the constellations at about fifty arc-seconds per year. So "Sun in Pisces" today (Vedic / sidereal) is "Sun in Aries" (Western / tropical) for the same moment. The difference is precession — and the offset is called Ayanamsha.

Vikram, Deck 36 · Precession of the Equinoxes

Earth doesn't just spin and orbit — it also wobbles. Imagine a spinning top whose axis slowly traces a cone in space. Earth does the same, completing one wobble in about 26,000 years. This is precession.

Precession means the vernal equinox — the intersection point of the ecliptic and the celestial equator — slowly drifts backwards through the constellations: Aries → Pisces → Aquarius. About 50 arc-seconds per year. Slow, but it adds up.

Two zodiacs result:

Ayanamsha is the offset between these two zodiacs — the cumulative drift since the two zodiacs last coincided. The deck lists three of the most-used calculations:

Earth 26,000 yr cycle precession tilted ~23½° · wobbling slowly
The wobble that creates the difference between Tropical and Sidereal zodiacs.

Vikram in class: "the Vedic chart and the Western chart for the same moment will show the Sun in different signs — the Vedic shifts back. That shift is the ayanamsha. Most software lets you pick which one." The course uses Lahiri by default.

↗ Why this matters in the Learning Companion: every chart you cast assumes an ayanamsha. The default in the page is Lahiri, matching class.
§ Nine

The Stellarium Lab · sky & chart side by side

From the class · Sessions 15 & 18 · Stellarium labs

"I would like you to try it out in Stellarium. So these are the three intentions. One is revision. Next is to look at it in Stellarium. And then to replicate."

Vikram, Session 18 · setting up the lab in real time

This is where every prior section earns its place. The decks (22, 29, 31, 47) give the procedure; Vikram runs the labs live on his screen in Sessions 15 and 18; the cohort follows along on their own machines. The whole purpose is one realisation: the chart on your screen and the sky outside your window are the same thing. One is the geometry written down. The other is the geometry, alive.

Two windows, side by side

The most powerful version of the lab uses two pieces of free software open at the same time, on the same birth details:

left window

Free Vedic chart in the browser. Type in your birth date, time, and place. Get a clean South Indian chart back, planets placed by sign and degree. Whole-Sign and Bhāva Chalit views available side-by-side.

right window

Free planetarium software (desktop or web). Set the same birth date, time, and place. The view rotates to show the actual sky overhead at that moment — horizon, signs, planets, stars, all in their real positions.

The exercise is to keep both open and move between them. Find the Sun on the deva.guru chart — what sign, what degree? Now find the Sun in Stellarium for the same moment. Where is it on the horizon? How high above? What sign is rising in the east at that moment — does it match the Lagna in your chart? When the two windows agree, the chart stops being abstract.

Procedure — Deck 22 · Your Sky at Birth

For the serious student — Parashara's Light

Once deva.guru and Stellarium feel familiar and you want more depth, Parashara's Light is the desktop software many serious students of Jyotisha use. It gives you Sripati cusps, divisional charts, dashas, transits — every layer Vikram references in class. Paid, but worth it for the stage where reading individual placements gives way to reading whole patterns over time.

Watching retrograde happen live

From Deck 47 (Apparent Motions): use Stellarium's time controls to identify the planets currently in retrograde, and find which planet retrogrades next. Speed up time. Watch the loop happen on screen — a planet moving forward against the stars, slowing, drifting backwards, slowing, then forward again. What BPHS describes in eight technical terms is just this loop, sped up. Once you have seen it once, retrograde is no longer abstract.

Why this matters

In Vikram's phrasing: the lab is to "build a real, embodied connection with each graha. Lays foundation for understanding transits — mentally, spatially, and energetically." Without this step, the rest of the course stays on paper. Spending an hour with deva.guru and Stellarium open at the same time is the single highest-leverage thing a learner can do between sessions. Many Astrology 101 concepts simply will not click until the geocentric sky is something you have seen, not just read about.

↗ This lab loops back to § One — The Geocentric View. Everything else on this page (ecliptic, coordinates, celestial equator, retrograde, precession) is preparing you for the moment Stellarium opens and the chart matches the sky. The same exercise feeds the chart you read in Learning Companion and Interpret · beta.
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