Combustion (asta or moudhya) is a traditional condition associated with a graha’s proximity to the Sun. A Jyotish reader usually starts with the difference between their zodiacal longitudes and consults a stated orb convention. Traditionally, combustion can restrict a planet’s independent delivery of its significations. Its sign strength, dispositor, functional rulership and the Sun’s condition determine how much that restriction matters and which house topics carry it.
A chart calculation versus visibility in the sky
Take the Sun’s and planet’s longitudes in the same zodiac and coordinate convention. Find their shortest difference around the 360° circle. For example, a Sun at 359° and Mercury at 5° are 6° apart, not 354°. Compare the gap with the threshold used in the particular text or software. If the degrees are unknown, a same-sign conjunction is insufficient to establish a precise orb; planets in adjacent signs can also be close.
This longitude calculation is an astrological convention. Actual visibility near the Sun also depends on apparent sky position and observing conditions. The observational issue of solar glare and the interpretive rule should be kept distinct so that the calculation is not mistaken for a complete chart judgment. NASA’s skywatching discussion of solar glare addresses observing planets, not horoscope outcomes.
One documented set of thresholds
The following example comes from R. Santhanam’s notes accompanying the Brihat Parashara Hora Shastra, divisional-consideration discussion. The numbers appear in the translator’s explanatory table, not as a universal equation in the cited verses. Some columns distinguish direct and retrograde motion:
| Graha | Direct-motion threshold | Retrograde threshold in those notes |
|---|---|---|
| Moon | 12° | — |
| Mars | 17° | 8° |
| Mercury | 14° | 12° |
| Jupiter | 11° | 11° |
| Venus | 10° | 8° |
| Saturn | 16° | 16° |
The table is a reference to one translation’s notes, not a measured severity scale. Other source traditions and software choices may differ. Before comparing two charts or tools, check their definitions of longitude, motion and boundary. The nodes Rahu and Ketu are not physical planets in solar glare; the cited notes do not treat them as combust. The Moon also has its own phase and Sun–Moon relationship to consider rather than mechanically interpreting it like Mercury.
What else changes a traditional reading?
Combustion is different from exaltation or debilitation: one concerns closeness to the Sun under a stated rule, the other a sign-dignity relationship. A planet can have both conditions. Chart readers may additionally consider the sign lord, house rulership, aspects and conjunctions. A strong dispositor and supportive aspects can preserve useful capacity, while debilitation, a weak lord and repeated affliction can compound the restriction. Judge the specific houses the planet carries and whether the relevant periods activate that weakness. Debilitation and Neecha Bhanga explain the other technical category.
Why are there separate planet pages?
The Moon article separates solar proximity from lunar phase. Mercury distinguishes a close orb from Sun–Mercury conjunction terminology, and Mars separates combustion from Manglik house rules. The Venus, Jupiter and Saturn articles distinguish their individual traditional subjects from sign dignity and solar distance. The technical orb calculation remains here; each planet page develops the particular functions that can be supported or obstructed.
Is a planet “severely combust” at 0–3°? There is no universal severity table that turns an orb into a percentage or a fixed result. Record the exact separation and your source instead.
Does a combust planet need a remedy or gemstone? Not on the basis of this condition alone. A remedial recommendation must identify the problem, the planet’s functional role and whether strengthening it is actually desirable. The orb calculation alone supplies none of those decisions.
For the larger vocabulary, see Jyotish foundations.