NASA: Among the findings tallying 197 initial planet candidates, scientists have confirmed 104 planets outside our solar system. Among the confirmed is a planetary system comprising four promising planets that could be rocky. by Michele Johnson via Ames Research Center
'The planets, all between 20 and 50 percent larger than Earth by diameter, are orbiting the M dwarf star K2-72, found 181 light years away in the direction of the Aquarius constellation. The host star is less than half the size of the sun and less bright. The planets’ orbital periods range from five and a half to 24 days, and two of them may experience irradiation levels from their star comparable to those on Earth. Despite their tight orbits — closer than Mercury's orbit around the sun — the possibility that life could arise on a planet around such a star cannot be ruled out, according to lead author Crossfield, a Sagan Fellow at the University of Arizona's Lunar and Planetary Laboratory.
'The researchers achieved this extraordinary "roundup" of exoplanets by combining data with follow-up observations by earth-based telescopes including the North Gemini telescope and the W. M. Keck Observatory in Hawaii, the Automated Planet Finder of the University of California Observatories, and the Large Binocular Telescope operated by the University of Arizona. The discoveries are published online in the Astrophysical Journal Supplement Series.'