At roughly 11 light-years away, GJ 887 - a red dwarf roughly half as massive the Sun - hosts one of the closest multi-planet systems to our Solar System, researchers report. According to a new study, the nearby system is home to at least two, and perhaps three, super-Earth sized exoplanets. Their proximity offers a promising opportunity to study exoplanet atmospheres using the soon to be launched James Webb Space Telescope. A popular method for discovering exoplanets uses Doppler measurements of a star's motion to reveal the gravitational pull of any planets orbiting around it. Using this approach, Sandra Jeffers and colleagues observed GJ 887 each night for three months. Combining their data with archival measurements of the star, spanning nearly 20 years, Jeffers et al. detected the presence of at least two super-Earth sized planets, tightly circling the nearby red dwarf with orbital periods of 9.3 and 21.8 days. They also found evidence for a possible third planet farther out, with an orbital period of approximately 50 days. The authors suggest that both of the confirmed planets are likely too hot to maintain liquid water on their surfaces. However, the more distant location of the unconfirmed third planet may place it within GJ 887's so-called "habitable zone." GG 887 is less active than other red dwarfs, so the newly discovered worlds may be spared from harmful solar flares common to that type of star. "If someone had to live around a red dwarf, they would want to choose a quieter star like GJ 887," writes Melvyn Davies in a related Perspective. "If further observations confirm the presence of the third planet in the habitable zone, then GJ 887 could become one of the most studied planetary systems in the Solar neighborhood," Davies writes.
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Science