Combustion, cazimi and under the beams

Why nearness to the Sun matters

Ancient astrologers judged a planet partly by whether it could be seen. As a planet approaches the Sun in the sky, it disappears into twilight glare and stops being visible at dawn or dusk. The tradition read that invisibility as a loss of public power: a planet nobody can see cannot openly act. Combustion is therefore an accidental condition, one of position and timing, and it applies whatever the planet's sign.

The rule flips at the centre. A planet inside the Sun's disc is not burned but enthroned, like an adviser seated beside the king. The Arabic-derived term cazimi means in the heart of the Sun. Lilly scored cazimi at plus five, combust at minus five and under the beams at minus four.

The three zones

The zones nest: a planet 5° from the Sun is combust and also within the beams, and the stronger condition is the one you read. Distances are measured in longitude. Some older authors stretch the beams to 17°, but this site uses 15°. Seventeen arcminutes is roughly the apparent radius of the Sun's disc, which is why the cazimi zone is so narrow.

How to read a combust planet

A combust planet merges with the Sun's purposes. The person may find it hard to tell what that planet wants apart from what their ego wants. Combust Mercury often brings sharp, subjective thinking that struggles to step back from its own view. Combust Venus can mean affection kept private or values tied closely to self-image.

Two exceptions were widely taught. A planet in its own domicile or exaltation was said to resist combustion. Many authors also held that a planet in a different sign from the Sun is not strictly combust, only under the beams.

Under the beams is milder: the planet works quietly or behind the scenes. Cazimi is rare, since the window lasts only hours for most planets, and it gives the planet unusual clarity and authority.

Combustion in modern practice

Many modern astrologers read a planet near the Sun as a conjunction rather than a debility, stressing how the planet fuses with the sense of self. Both readings can be useful: the fusion is the modern language for what the tradition called being absorbed by the Sun's light.

The classical rule applies to the Moon and the five visible planets. Mercury and Venus are combust often, because they never stray far from the Sun. Mars, Jupiter and Saturn are combust only around their conjunction with the Sun, which they reach once a year or less. Neptune and Pluto cannot be seen with the naked eye, and Uranus only barely, so most astrologers do not apply combustion to them.

Combustion in example charts

Mercury 4° from the Sun: combust. Thinking runs fast and is coloured by personal conviction. It helps to test ideas on someone else before acting on them.

Mercury 10 arcminutes from the Sun: cazimi. The same planet, a few degrees closer, becomes a source of focused, confident thought.

Venus 12° from the Sun: under the beams. Taste and affection are real but low-key, shown in private rather than on display.

Saturn in Capricorn 3° from the Sun: combust, but in its own domicile, so many authors would treat it as protected. Discipline and identity are tightly bound, and the person may hold themselves to strict standards.

Moon 6° from the Sun: combust, born just before or after the New Moon. Feelings and will start together, and emotional needs can go unnoticed.

Jupiter 2° from the Sun in a different sign: by the out-of-sign rule many authors would call it under the beams rather than combust. Faith and generosity stay personal and are rarely announced.