user: Question: What Constellation has a 20h56m40s Right Ascension (J2000)?
Columns: ['NGC number', 'Object type', 'Constellation', 'Right ascension ( J2000 )', 'Declination ( J2000 )']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [6913.0, 'Open cluster', 'Cygnus', '20h23m56s', '°31′']
SQL:

assistant: SELECT "Constellation" FROM "Table" WHERE "Right ascension ( J2000 )" = '20h56m40s';