Once upon a time, there lived a woman in a village. She had seven sons. One day she went to the forest to bring soil for the renovation and painting of her home (this was in the month of kartik just before the Hindu festival Deepawali . She started digging soil with axe nearby a den. Suddenly the woman's axe fell on the cub in the den and the cub died. The woman felt very sorry and sympathetic. She took soil from the forest and came back. 

Few days later, all her seven sons died within a year. She was very sad. One day she narrated her woes to old ladies in her village, she was crying and told them that she didn't commit the sin and it happened unintentionally. She narrated to the ladies that once when she was digging for the soil in the forest her axe fell on the cub and thereafter within a year all my seven sons died. The ladies appreciated for confessing her guilt and then these ladies told that by confessing the sin she has atoned her half of the sin. 

They suggested the woman to pray the goddess Ashtami Bhagwati by sketching the face of the cub. By the grace of god your sin will cast off. The woman kept fast on the Kartik Krishna Ashtami and then onwards she started praying and keeping fast regularly. By the power of her prayer the God's grace showered and she could get back her all seven son. Since then, it became a ritual to worship the goddess Ahoi Ashtami Bhagwati religiously every year.