Karthikai, or Karthigai, is the eighth month in Tamil calendar and it derives its name from the star ‘Krithiga.’ The Mondays in the month are dedicated to Lord Shiva and is known as Karthikai Somavaram. Ayyappa devotees start the 41-day Vratam and take a pilgrimage to Sabarimala in this month. In 2015, Tamil Month Karthigai begins on November 17 and ends on December 16. The image that comes to mind when Karthikai Masam is mentioned is that of lamps which are lit in all the houses and streets.
It is believed that Lord Shiva gave darshan to Lord Vishnu and Brahma in the form of a pillar of fire with no ends known as Lingodabhavamurti. This form is also referred as Annamalai Deepam in Tamil and is celebrated as Karthigai Deepam. On this day small lamps are lit in all places in homes and in streets.
Another significant event in this month is the Mahabharani which is observed in Shiva temples by lighting bonfires.
The month is also highly auspicious for Lord Muruga devotees as the month is named after the six Krithika stars. Son of Lord Shiva, Muruga was born as different babies – Shanmugha and was looked after by the Six Kritika stars. Later Goddess Parvati joined the six babies to give birth to Kartik or Muruga.