Daksha was one of the Prajapati, son of Brahma, and among his foremost creations. Sati, the youngest daughter of Daksha, was deeply in love with the god Shiva and married him. However, Daksha did not like Shiva because of his status.
With the prime motive of insulting Shiva, Daksha initiated a great yajna, similar to that of Brahma. The yagya was to be presided over by the sage Bhrigu. He invited all the gods, Prajapatis and kings to attend the yagya and intentionally avoided inviting Shiva and Sati.

Sati came to know about the grand yagya organized by her father and asked Shiva to attend the yagya. Shiva refused her request, saying that it was inappropriate to attend a function without being invited.

She constantly pleaded and urged Shiva to let her attend the ceremony, and became adamant in her demands without listening to the reasons Shiva provided for not attending the function. He allowed Sati to go to her parents’ home, along with his followers including Nandi, and attend the ceremony, but refused to accompany with her.

Daksha insulted sati in front of all the other guests at the ceremony to which she had not been invited. He called Shiva an atheist and cremation ground dweller. Sati felt deep remorse for not listening to her beloved husband.
Sati cursed daksha and warned that the wrath of Shiva would destroy him and his empire. Unable to bear further humiliation, Sati committed suicide by jumping into the sacrificial fire.

Shiva was deeply pained upon hearing of his wife’s death. His grief grew into a terrible anger. Shiva vowed to destroy the Yagya. What ensued was great destruction and Yagya was extinguished by Shiva’s third eye. In order to avoid the further wrath of Shiva, Yagya took the form of a deer and flew into the sky. Shiva as Kala, or the lord of time, pursued the Yagya in the sky and killed him. After his death, Yagya’s deer head was established among the stars as Mrigasira nakshatra and became the emblem for sacrifice. Yagyas performed when the Moon is in Mrigasira nakshatra have special significance and have the power to bring many spiritual rewards too.