Almost 30 years after the first planet outside our solar system was discovered, more than 7,000 other exoplanets have been identified. Now, it’s time to add another to the list.
A team of researchers have confirmed an Earth-like planet named HD 20794 d, they report in the journal Astronomy and Astrophysics. The exoplanet is especially interesting to astronomers because at a mere 19.7 light-years away, it’s practically a neighbor.
HD 20794 d, the star around which the newly identified planet rotates “is not an ordinary star,’’ Xavier Dumusque, an astronomer at the University of Geneva and co-author of the study, said in a press release. ‘‘Its luminosity and proximity makes it an ideal candidate for future telescopes whose mission will be to observe the atmospheres of exoplanets directly.’’
The Promise of Water
The position of the planet in relation to that star also provides the possibility that it could hold water. So astronauts searching for signs of life beyond Earth are especially interested in it.
HD 20794 d orbits its host star in 647 days. Although that’s almost twice as long as an Earth year, it’s only 40 days less than Mars needs to circle our Sun.
Unlike Earth and Mars, HD 20794 d’s orbit is more elliptical than circular. That orbital pattern is especially interesting to astronomers, because if the planet contains water, it would likely be liquid during its closest passages to the sun, and ice when its farthest away.
Read More: 6 Exoplanets in our Universe That Could Support Life Other Than Earth
The Search for Life
Finding this particular exoplanet was no easy task; it required more work than just pointing one telescope to the sky and noticing the novel celestial body. Instead, it required analyzing more than 20 years of data from several instruments, then using an algorithm to filter out waves coming from other sources.
‘‘We analyzed the data for years, carefully eliminating sources of contamination,” Michael Cretignier, a research fellow at Oxford University and a co-author of the paper, said in a press release.
The exoplanet’s size, proximity to Earth, and potential to hold water makes it a prime candidate to search for life, as well as testing hypothesis about conditions that could support it. New instruments, like the European Southern Observatory’s Extremely Large Telescope (ELT), will hasten that search when they come online.
Until then, the search for more exoplanets will continue.
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Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
Source : Discovermagazine
