user: Question: what is the constellation when the Right ascension ( J2000 ) is 10h18m58.4s?
Columns: ['NGC number', 'Object type', 'Constellation', 'Right ascension ( J2000 )', 'Declination ( J2000 )']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [3109.0, 'Irregular galaxy', 'Hydra', '10h03m06.7s', '°09′32″']
SQL:

assistant: SELECT "Constellation" FROM "Table" WHERE "Right ascension ( J2000 )" = '10h18m58.4s';