An international group of astronomers found that Tau Ceti, a nearby star-system, is orbited by not one but four Earth-sized planets and that two of them are also situated in a habitable zone. Tau Ceti is visible with the naked eye, as it just 12 light years away from our planet.
Tau Ceti Capable of Holding Life Forms?
The team of astronomers identified the presence of the four Earth-sized planets by examining the ‘wobbles’ of their sun-like star, tau Ceti. Large data sets modeling also helped differentiate between stellar surface activity noise from small signals from planetary gravitational pulls. This helped eliminate two other possible planet contenders.
“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,” stated Steven Vogt.
He is a study co-author and astronomy and astrophysics professor at UC Santa Cruz.
It also helped confirm the presence of four Earth-sized planets. These were all determined to have a low mass. The smallest planet is estimated to have a mass some 1.7 times that of Earth. Two of the four planets were also noted to be in the habitable zone. They might potentially even have a liquid surface, according to research.
However, they are not the ideal candidates for future habitability from more than one reason. One is that they are seemingly surrounded by a “massive” amount of debris. This is circling the planets and reportedly making them more vulnerable in the face of incoming comets and asteroids.
Tau Ceti is considered to be around the same size and about as bright as our own Sun. Also, observations indicate that it might be strong enough that the planets orbiting are not tidally locked. This means that all of their sides might be at one point, exposed towards the star.
The team of astronomers based its study on data gathered by the Chile-based European Southern Observatory and also Hawaii’s W.M. Keck Observatory.
A paper with the research results was accepted for publication in the Astrophysical Journal.
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