CREATE TABLE table_name_86 (ngc_number VARCHAR(255), declination___j2000__ VARCHAR(255), constellation VARCHAR(255), object_type VARCHAR(255))
Name the total number of NGC number for sagittarius and diffuse nebula with declination of °02′
    
SQL: SELECT COUNT(ngc_number) FROM table_name_86 WHERE constellation = "sagittarius" AND object_type = "diffuse nebula" AND declination___j2000__ = "°02′"