An unusual discovery was made by employees of the University.
If you believe the results of a recent study closest to our sun-like star near it can be four presumably sampletable planet, according to astronomers who conducted the study, at least two of these worlds may be inhabited. Star Tau Ceti is “only” 12 light years from us. Such proximity has long made it a subject of interest not only scientists, but also the creators of science fiction and video games. However, it looks like a potential star to support life can now be seen not only with a fantastic view.
Through the work of a group of scientists from the University of Hertfordshire under the guidance of Fabo Feng based on was very weak oscillations in the movement of the stars Tau Ceti due to the impact of the gravitational pool of smaller astronomical bodies have confirmed the existence of four exoplanets. To confirm the presence of planets orbiting stars allowed method Doppler spectroscopy (or measuring radial velocities, or the so-called wobble method), whereby it was noted a change in the speed of motion of the star, in the order of 30 cm/s. Scientists say that if the effectiveness of this method will be improved to the point where it will be possible to determine changes in velocity to 10 cm/s, then we get the threshold at which we can easily identify and separate the gravitational pool of exoplanets from the usual noise in the signal produced by the stellar fluctuations.
“We are very close to the correct scoping to the extent necessary for the search of earth-like planets,” notes Feng.
“Our ability in identifying such weak changes is an important achievement in the search for analogs of our own planet and allows you to better understand the difference between the habitability of such exoplanets compared to earth.”
Two planets nearest sun-like stars could be habitable
Comparison of the habitable zone Tau Ceti (above) to the habitable zone of the Solar system (bottom)
Discovered by a team of Feng worlds include two super-Earth (planets with a mass greater than earth’s), located on the borders of the so-called habitable zone of the star Tau Ceti. This means that they are in a region of space where not much hot and cold. So there are the necessary conditions to maintain the planets water is in liquid form, and possibly to the presence of life.
Two other, smaller planets are outside this “comfort zone” and orbit the star much closer. Although the presence of water, they maintain, most probably can not, they are one of the most compact earth-like planets found near sun-like star. The mass of each of which is only 1.7 times the mass of Earth.
It should be noted that this is not the first case when at Tau Ceti to discover potentially habitable worlds. The same team of scientists a few years ago announced the discovery of five planets orbiting this star. The latter study is likely an amendment to the previous one. And this time scientists are confident in their conclusions.
“Since that time we have significantly increased the sensitivity of our technology and was able to exclude two signals, which our team took over the planet then, in 2013,” says Mikko Tuomi, one of the researchers.
“However, no matter how you look at this star, everything points to the fact that near it there are at least four rocky planets”.
The presence of at least several candidates for habitable worlds, located in relative proximity with us, can not but rejoice. Maybe Tau Ceti and is much further than surrounded by our hopes Proxima b (located 4.2 light years from us), but at the same time is closer than TRAPPIST–1, located approximately 39 light years from Earth.
And yet scientists say that collecting bags and go to a new home is premature. So there is a very harsh environment. A dense ring of debris surrounding the system Tau Ceti, may indicate that the existing worlds are inhabited or not – are under constant threat of intense bombardment by asteroids and comets. But that’s not all. It is possible that two planets in question can be located on the border of the habitable zone Tau Ceti. In this case, the potential habitability of these worlds may be even lower than originally thought.
The next step for scientists will be to attempt to discern these worlds with telescopes (not just on the charts) and find out more about their nature through direct observation. By this time the story about the real level of potential habitability of Tau Ceti is still a matter of debate.
The results of a recent study will soon be published in the Astrophysical journal.
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