The Fifth Planet of HR 8799: A Whisper in the Roar of the Orchestra
The orchestra is playing fortissimo, and someone in the third row is whispering. Hearing that whisper is the challenge astronomers face at the star HR 8799: four bright giant planets drown out the faint light of a possible fifth, hidden very close to the star.
The HR 8799 system is a proving ground for direct exoplanet imaging.