Lord Siva's wife Goddess Umadevi once playfully closed His eyes which plunged the world into darkness. All living beings suffered in the dark. To absolve herse of this sin Mother Umadevi created a Sivalingam out of sand and worshipped at Kancheepuram.
At that instance, Lord Siva ordered her to proceed to Thiruvannamalai and do penance so that she could get half of His body. Likewise Mother Parvathi did penance at Pavalakundru with the help of Saint Gowthama. A demon called Makidasuran disturbed the penance of Mother Parvathi. The Mother took the form of goddess Durga Devi and destroyed him on the full moon day of the Tamil Month of Karthigai during the auspicious period of pradosham. Lord Siva presented himself in the form of Fire atop the hill and merged Goddess Parvathi on the left half of his body.
To commemorate this event, every year during the Tamil month of Karthigai in Kiruthigai Star, exactly at 6.00 p.m. Arthanareeswaramurthi presents himself as Jyothi Swaroopa to his devotees at the time of Karthigai Festival 10th day.