Tau Ceti

Astronomers have found four planets similar in size to Earth orbiting a star resembling the characteristics of the sun.
An international team of astronomers detected the four planets with masses as low as 1.7 Earth masses orbiting tau Ceti, a star about 12 light years away from Earth and visible to the naked eye.
The discovery represents the smallest planets ever detected around nearby sun-like stars, with two of the planets located in the habitable zone of the star and possibly able to support liquid surface water.
The astronomers found the planets by observing the wobbles in the movement of tau Ceti, which required techniques sensitive enough to detect variations in the movement of the star as small as 30 centimeters per second.
“We are now finally crossing a threshold where, through very sophisticated modeling of large combined data sets from multiple independent observers, we can disentangle the noise due to stellar surface activity from the very tiny signals generated by the gravitational tugs from Earth-sized orbiting planets,” Steven Vogt, Ph.D., a professor of astronomy and astrophysics at the University of California Santa Cruz and co-author of the study, said in a statement.

R&D Magazine.