Karthigai Deepam -- The Night Arunachala Becomes a Pillar of Fire

Karthigai Deepam, also spelled Kartikai Deepam, is a Tamil festival of lamps that has nothing directly to do with Diwali and only a partial overlap with Kartik Purnima, despite arriving in the same crowded stretch of the calendar. Diwali is fixed to Kartik Amavasya, the new moon, and belongs mainly to Lakshmi. Kartik Purnima, covered in full on Eternal Raga's dedicated page, is fixed to the ordinary full moon of the lunar month of Kartik and carries Dev Diwali at Varanasi, Guru Nanak's Gurpurab, and a Jain nirvana anniversary. Karthigai Deepam answers to a stricter rule than either: it requires the moon to be full on the specific day the Krittika star, the constellation Westerners call the Pleiades, is prevailing in the sky, within the Tamil solar month of Karthigai (mid-November to mid-December). Because the Tamil calendar is solar and most of North India's Kartik reckoning is lunar, the two systems drift apart from year to year, and Karthigai Deepam usually falls a few days before or after Kartik Purnima rather than on it. In 2026 the drift happens to close almost entirely: both the Krittika-Purnima alignment and the North Indian Kartik Purnima tithi land on 24 November, a coincidence of the calendar rather than a sign that the two festivals are secretly one, and readers should not expect the same alignment in most other years.

This article covers Karthigai Deepam specifically: its rule for falling when it does, the Lingodbhava myth behind it, and the Maha Deepam ritual at Tiruvannamalai that makes it Tamil Nadu's own major festival of light, distinct in date, myth, and ritual from both Diwali and Kartik Purnima even in a year when their calendars nearly touch.

The story behind Karthigai Deepam is the Lingodbhava, told at length in the Skanda Purana's Arunachala Mahatmya, a section of some two thousand verses devoted specifically to this one hill. Brahma and Vishnu once fell into a dispute over which of them was supreme. To settle it, Shiva manifested between them as a limitless column of fire, with no visible beginning or end, and challenged them to find either end. Vishnu took the form of a boar and dug downward without limit; Brahma took the form of a swan and flew upward without limit. Neither found an end. Vishnu returned and admitted defeat honestly. Brahma, unable to bear the admission, lied that he had reached the top and found a screwpine flower there to prove it, at which point the flower itself, and in some versions the cow Kamadhenu, testified to the falsehood. Shiva, angered at the lie, cursed Brahma to have no temple dedicated to him alone in most of India, a curse Hindu tradition still points to when explaining why dedicated Brahma temples are so rare. At the devas' entreaty, the column of fire cooled and settled into a physical hill, Arunachala, so that the mountain at Tiruvannamalai is not merely named for the event but is held to be its literal remains.

The temple at the foot of the hill, Annamalaiyar (also called Arunachaleswarar), enshrines Shiva as the Agni Lingam, the fire-form among the five elemental Shiva shrines of Tamil Nadu known as the Panchabhoota Sthalams (earth at Kanchipuram, water at Tiruvanaikaval, air at Kalahasti, ether at Chidambaram, and fire here). Karthigai Deepam re-performs the Lingodbhava each year at the point the myth says it happened: on the evening of the festival's final day, priests carry ghee and camphor up the hill to a massive cauldron set on the summit, and light it at dusk in a ceremony called the Maha Deepam. Temple accounts for recent years put the quantity of ghee used at roughly 3,000 to 3,500 kilograms, and the resulting flame is visible for a considerable distance across the surrounding plain, a modern re-enactment of the pillar the myth describes as having no visible limit in either direction. The Maha Deepam itself is the climax of a ten-day temple festival, the Karthigai Brahmotsavam, that in 2026 runs from 15 to 24 November, with daily processions of the temple's deities through Tiruvannamalai's streets building toward the final night.

Most Hindu festivals travel: a Diwali diya can be lit in any home, a Kartik Purnima bath can be taken at any river. Karthigai Deepam is unusual in how tightly it stays anchored to one hill. Households across Tamil Nadu do keep a simpler version at home, lighting rows of clay lamps, or vilakku, on windowsills and courtyard thresholds through the ten nights of the temple festival, and other Murugan and Shiva temples across the Tamil-speaking world hold their own, smaller Deepam observances on the same night. But the festival's centre of gravity has never moved from Tiruvannamalai, where the size of the crowd, the specific quantity of ghee, and the visibility of the flame across the plain are treated as measures of the festival's success in a way that has no real equivalent elsewhere.

This regional concentration is worth stating plainly rather than smoothing over. Karthigai Deepam is a major public event across Tamil Nadu and, less visibly, in Tamil communities in Sri Lanka, Malaysia, and Singapore, and it is comparatively unfamiliar outside those communities, in the same way Eternal Raga's Skanda Shashthi article notes for that other Tamil Murugan festival. That is a real, honestly stated pattern of regional intensity, not a gap in coverage, and readers coming to Karthigai Deepam from a North Indian Diwali or Kartik Purnima frame should expect a festival built around a specific hill and a specific temple far more than around a household ritual that travels.