1. Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1

2. NASA discovery (22th February 2017):
Detection  of a system of seven Earth-sized planets just 40 light-years away
 TRAPPIST–South,  NASA Spitzer Space Telescope,  Very Large Telescope 
At least the inner six planets are comparable in both size and temperature to the Earth (rocky).
The host star: 8% the mass of the Sun (a bit larger than Jupiter)

3. Orbital properties:

5. Habitable zone:
All seven planets discovered
in the system could potentially
have liquid water on their surfaces
TRAPPIST-1b, c and d, are probably
too hot to support liquid water

6. Transit method for detecting exoplanets:

7. TTV: Transit-Timming variation