The two wives of kashyapa mahaR^iShi karththuru, vinathai had a fight in between them about the black spot on the tail of uchchaisiravas - indra's horse. Repenting they came to thirumIyachchUr and worshiped the Lord. The Lord blessed then and gave them an egg each, asked to preserve for an year to get splendid sons. They got garuDan, aruNan respectively.
When aruNan took the form of mOhini (charming girl) sun despoilt her. When aruNan pleaded to the Lord, He cursed sun to get darkened. As per His advise, sun worshiped the Lord at thirumIyachchUr for seven months. Still as his darkness did not change, he cried in grief, "hE migurA". The Goddess got angry at the sun for shouting in Their abode. The God pacified her saying sun was looking for relief. By His Grace sun was cured. The pacified Goddess does austerities getting the name sha.ntanAyaki.
From the mouth of shakti appeared the vachini dEvatas and they gave to the world lalitA sahasranAmam.
hayagrIvar conveyed to sage agasthiyar lalitA sahasranAmam. As told by him agasthiyar came to this temple and worshiped the God in the AmlA phalAdi kraNa pUja as done by the sun and saluted srI lalitAMbikA.
yama dharma rAja worshiped the Lord here.
Sun worships the Lord with his rays falling on the Lord from 21st to 27th of chiththirai.