A Scientist from the University of California has discovered four earth sized planets in orbit around the closest sun-like star to the solar system. That sun-like starcalled as Tau Ceti.
The two worlds at the boundary of star Tau Ceti’s “habitable zone” are the region of a system of planets that are similar in size to Earth.
These are the smallest planets ever found around a star like our sun. However, unlike common smaller stars, such as the red dwarf stars Proxima Centauri and Trappist-1, they are not so faint that planets would be tidally locked, presenting the same side to the star.
Astronomers are excited by the recognition because the planets have masses as small as 1.7 times the mass of the Earth.Two of them are super-Earths located in the habitable zone of the star, meaning they could sustain liquid surface water.
The planets were recognized by observing the wobbles in the motion of Tau Ceti. This needs techniques to detect variability in the motion of the star as small as 30 cm per sec.
Co-author Steven Vogt, professor of astronomy and astrophysics at UC Santa Cruz says, “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 small scale signals caused by the gravitational pull from Earth-sized orbiting planets.”
Size and brightness of Tau Ceti are very similar to the sun.