What is Combustion (Burned by Sun)?
When a planet comes within approximately 8°30' of the Sun, it is said to be combust—overwhelmed by the Sun's light and heat. The planet's significations become harder to access, like trying to see a star during daylight. Different planets have different combustion thresholds, and the closer to the Sun, the stronger the effect. Combustion is considered a significant debility in traditional astrology.