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Astronomers of the European Southern Observatory have discovered
a potentially habitable planet in the system of a nearby star

Russian version

    November 15, 2017 the European Southern Observatory (ESO) reported on their web-site about the discovery of an exoplanet in the system of the nearby star Ross128.

    The star Ross128 is a red dwarf. Red dwarfs have low masses, less than half the mass of the Sun. Such stars are among the coolest and faintest stars. They are the most common stars. Ross128 is situated in the constellation of Virgo at about 11 light-years from the Solar system. The estimated mass of the star is 0.168 solar masses and luminosity - 0.0036 solar luminosity. Its age is greater than 5 Gyr, i.e., it is older than the Solar system.

    11-year observations from 2005 to 2016 of Ross128 with the HARPS (High Accuracy Radial Velocity Planet Searcher) instrument mounted at the 3.6-m telescope of the La Silla Observatory (Chile) allowed European astronomers to conclude that there is a planet that orbits around this star. The radial velocity method was used in the study: the planet has a gravitational effect on its star, and this is measured with the Doppler effect.

    The newly-discovered planet is called Ross128b and has a mass of at least 1.35 masses of the Earth. It is separated from the parent star by a small distance---0.046 astronomical units (i.e., 4.6% of the Earth's distance from the Sun, or 6.9 million kilometers) and, therefore, makes one full orbital revolution in 9.86 days. Although, the planet receives only about 1.38 of the energy that the Earth receives from the Sun because of the faintness of the parent star. Thus, Ross128b can hypothetically have conditions for life existence on its surface. In the future, using more powerful telescopes astronomers hope to find biomarkers on this planet.
The original text is available in the preprint archive: https://arxiv.org/abs/1711.06177. Authors of the study: Xavier Bonfils, Nicola Astudillo-Defru, Rodrigo Diaz, Jose-Manuel Almenara, et al.
The news-release of ESO: https://www.eso.org/public/russia/news/eso1736/?lang.

Contact - Gadelshin D.R., SAO RAS Research Assistant
Fig.1. Visualization of the temperate planet Ross128b with its parent star - a red dwarf - against the background. Source: ESO/M.Kornmesser