Combustion (Ast) in Vedic Astrology
Combustion (Sanskrit: Moudhya or Ast) occurs when a planet comes too close to the Sun in the Kundli and is "burnt" by solar rays. The combust planet loses much of its ability to deliver positive results for the houses it rules and occupies.
Combustion Degrees
Each Graha has a specific orb within which it is considered combust: Moon within 12 degrees, Mars within 17 degrees, Mercury within 14 degrees (12 if retrograde), Jupiter within 11 degrees, Venus within 10 degrees (8 if retrograde), and Saturn within 15 degrees of the Sun. These thresholds come from classical Parashari texts.
How Combustion Is Evaluated
Combustion is measured as the degree difference between the Sun and the planet in question. The closer a planet is to the Sun, the more severe the combustion. A planet at 2° from the Sun is more strongly combust than one at 10°, even though both fall within the threshold. Astrologers check whether the combust planet is simultaneously retrograde, which adds Cheshta Bala (motional strength) and may partially offset the combustion. The sign matters too: a combust planet in its exaltation sign has strong positional dignity (Sthana Bala) but weakened independent expression — it may deliver erratic results, capable of achievement but with unpredictable timing. The Shadbala system accounts for combustion within the overall strength score.
Classical Source
The combustion thresholds for each planet are specified in the Brihat Parashara Hora Shastra, which devotes specific chapters to Moudhya (combustion) and its effects on planetary strength. The Saravali by Kalyanavarma provides additional detail on sign-specific combustion results. The Phaladeepika discusses combust planets in the context of Yoga formation — noting that a combust planet may lose its ability to deliver the full results of a Yoga it participates in. Classical texts universally treat combustion as a significant debility in Shadbala calculations.
Practical Example
Consider a chart where Jupiter is at 15° Virgo and the Sun is at 22° Virgo — a gap of 7°, within Jupiter's 11° combustion threshold. Jupiter is combust. For a Sagittarius Ascendant native (where Jupiter rules the 1st and 4th houses), the Lagna lord is weakened. During Jupiter Mahadasha, the wisdom and fortune themes are present but come with effort and delay rather than freely. If Jupiter is also in debilitation (Capricorn) and combust, the compound weakness is substantial and remedies become particularly important.
Effects of Combustion
A combust planet's significations suffer. Combust Venus may weaken marital harmony, combust Jupiter can reduce wisdom and fortune, and combust Mercury may impair communication or analytical ability. However, combustion does not destroy a planet entirely — it makes its effects subtler, internalized, or delayed.
Combustion vs. Other Weaknesses
Combustion is distinct from debilitation, where the planet is in its weakest sign. A planet can be combust yet in its exaltation sign, creating a mixed result. Similarly, a retrograde combust planet has unique interpretive nuances — some texts consider retrogression to partially offset combustion.
Remedies for Combust Planets
Vedic astrology prescribes specific remedies for combustion, including gemstones for the combust planet, mantras to its ruling deity, and charitable acts on days governed by that planet. Strengthening the combust planet through these measures can mitigate adverse effects.
