According to the research published in Astronomy and Astrophysics recently, new ways of investigating helped scientists find a “super-Earth” planet in the habitable zone of HD 40307 star.
HD 40307, the dwarf star of Pictor constellation, is located 42 light years from Earth and can’t be compared to the Sun as it’s much cooler and smaller. It will be recalled that first three planets revolving around the star of HD 40307 were discovered in 2008.
New research mentioned above spotted three more planet worlds around the parent star, including one that presumably can support life as we know it.
HD 40307g is the outermost of three discovered astronomical bodies and lies in the so-called “habitable zone” – an area, where liquid water, a required condition for life, can exist. As regards our Solar System, it is safe to say, that Earth and Mars are located within our sun’s habitable zone.
Whereas the orbit of the newfound exoplanet is situated at a distance of 56 million miles from the central star, the other five planets of the system are reckoned to rotate so close to the orange star that hot temperatures make water liquidity impossible.
HD 40307g, classified as a “super-Earth”, has the mass equal to seven times that of Earth. One year on the alien planet takes 197.8 in the rough, Space.com states.
Researches assume that the planet doesn’t have one face constantly turned toward HD 40307. On the contrary, a super-Earth is considered to be rotating on the axis of its own. That’s why it seems fair to suppose that day and night cycle similar to the one we have on Earth can likely take place on HD 40307g.
“Just as Goldilocks liked her porridge to be neither too hot nor too cold but just right, this planet or indeed any moons that it has lie in an orbit comparable to Earth, increasing the probability of it being habitable,” – study co-author, astronomer Hugh Jones, of the University of Hertfordshire in England comments.
“The research team used the Harps instrument at the European Southern Observatory’s La Silla facility in Chile. Harps does not spot planets directly – it detects the slight changes in colour of a stars’ light caused by planets’ gentle gravitational tugs – the “redshift” and “blueshift” that small motions cause,” BBC reports.
It should be noted that HAPRS stands for High Accuracy Radial velocity Planet Searcher instrument, a light-splitting spectrograph. In the new study, scientists re-analyzed observations and high-precision measurements of the HD 40307 system made by this instrument so that it helped to reveal three new planets, including the “super-Earth”.
“All we know at this point is that it has a minimum mass of about 7.1 Earth-masses. We have no explicit follow-up planned, thought the HARPS team is probably still gathering more data, and may in the future be able to confirm these results, and perhaps add even more planets to the brood,” astronomer Steven Vogt, with the University of California’s Lick Observatory, wrote in an email to Discovery News.
Many more observations are necessary to broaden this discovery. Now scientists are planning to use space-based telescopes to receive a more detailed look at the new planet and examine its composition.