Table schema:
CREATE TABLE table_name_77 (declination___j2000__ VARCHAR, constellation VARCHAR, right_ascension___j2000__ VARCHAR)

Question: what is the declination (j2000) that has a constellation of hydra and a right ascension (j2000) of 10h46m44.9s?
SQL: SELECT declination___j2000__ FROM table_name_77 WHERE constellation = "hydra" AND right_ascension___j2000__ = "10h46m44.9s"