SWEEPS (Sagittarius Window Eclipsing Extrasolar Planet Search) used Hubble’s Advanced Camera for Surveys to monitor a portion of the galactic bulge in Sagittarius continuously for seven days, shooting one picture every six minutes.
There were 180 planet-transit candidates and only the best 16 was choosen. Two of them have been confirmed as outer planets. Each one of the candidates is a roughly Jupiter-size body that orbits its host star in just 4 days or less. Five of the candidates whip around their stars in less than an Earth day. They are grouped into a new category, ultra-short-period-planets.
