On the full moon day of the month of Kartika (November-December) which falls on the ascension of the Kritigai star, the Hindus celebrate the Kartika Deepam. It is on this day that the huge beacon is lit on the holy hill Arunachala, in South India.
Once Lord Shiva assumed the form of a hill at Tiruvannamalai in South India. Here He quelled the pride of Brahma and Vishnu who were quarelling as to their relative greatness. One day, when Lord Shiva was in meditation, Parvati left Him and went to the hill of Arunachala. There She performed penance. She was the guest of the sage Gautama. It was during Her penance here that Mahishasura was killed by Durga hidden by Parvati. Parvati saw Shiva as Arunachalesvara. She was taken back by the Lord to His side, and made His Ardhangini once more, that is, She occupied half of the body of the Lord.Arunachalesvara is Tejo Lingam. Arunachala or the Tiruvannamalai Hill is the place that represents the fire element. (The five elements are represented by five holy places in India.)
When the light on the top of the Tiruvannamalai Hill is unveiled on the Kartigai Deepam day, people see the big light and worship it. They recite again and again in a loud voice “Harohara”. The esoteric meaning is that he who sees the light of lights that is burning eternally in the chambers of his heart through constant meditation attains immortality. The light on the Arunachala brings the message to you that the Self or Lord Shiva is self-effulgent, He is the light of lights.On the Kartika Deepam day in South India, people make bonfires in front of temples in the evening. It is said that Lord Shiva burnt the chariots of several demons who were torturing sages and celestials. This bonfire symbolises this legend.
People place rows of earthen lamps in front of their houses on the evening of Kartigai Deepam and worship the Lord. They also light a variety of fireworks.Annihilate the three impurities, namely, egoism, selfish action and delusion. Burn the mind, senses and the desires in the fire of knowledge of the Self or Shiva-Jnanam. Attain full illumination and behold the light of lights, which illumines the mind, intellect, sun, moon, stars, lightning and the fire. This is real Kartika Deepam.May the light of lights illumine you all! May Lord Shiva bless you with more light! May you merge in this supreme light and attain the eternal abode of bliss and immortality!