A calm star with a busy planetary system<\/h2>\n\n\n\n
GJ 887, also called Gliese 887 and Lacaille 9352, is a cool “red dwarf<\/a>” that puts out only a few percent of the Sun\u2019s light. That low energy shifts the habitable zone inward. Planets can orbit quickly and still be potentially temperate.<\/p>\n\n\n\n In the new analysis, GJ 887d orbits about 20 million miles from its star, closer than Mercury is to the Sun, yet receives about 80% of the energy Earth gets. The same data confirm three other planets on tighter orbits, plus a weaker extra signal that could be another small planet. The team says that last signal needs more data.<\/p>\n\n\n\n The work comes from an international team led by astronomer C. Hartogh at the Institute of Astrophysics and Geophysics at the University of G\u00f6ttingen, with partners including the University of St Andrews and Italy\u2019s National Institute for Astrophysics. <\/p>\n\n\n\n Their paper, “RedDots: multiplanet system around M dwarf GJ 887 in the solar neighborhood,” reanalyzed existing observations and added new ones to test whether the 51-day signal was real.<\/p>\n\n\n\n They used the radial velocity method, which detects a planet by measuring a star\u2019s tiny back-and-forth motion. <\/p>\n\n\n\n The signal was measured with the HARPS spectrograph<\/a> and the ESPRESSO spectrograph, instruments operated in Chile by the European Southern Observatory. Because starspots can imitate planets, the team also used a statistical model called a “Gaussian process” to subtract the star\u2019s own noise.<\/p>\n\n\n\n NASA defines a habitable zone as “the distance from a star at which liquid water could exist on orbiting planets\u2019 surfaces,” sometimes called the “Goldilocks zone.” That definition is in this official habitable zone guide<\/a>. It is a useful filter, but it is not a guarantee of oceans or biology.<\/p>\n\n\n\n For GJ 887d, the study\u2019s basic temperature estimate without atmospheric warming is below freezing by Earth standards. <\/p>\n\n\n\n A thicker atmosphere could warm it, but too much greenhouse warming can turn a planet into an oven, as Venus shows with temperatures around 867 degrees Fahrenheit. And with about six times Earth\u2019s mass, GJ 887d could be rocky or it could have a deep, gas-rich atmosphere.<\/p>\n\n\n\n Red dwarfs can produce intense flares that erode atmospheres, which is one reason Proxima Centauri b remains controversial. GJ 887 looks calmer, and a 2020Science<\/em> report highlighted its unusually low activity as good news for atmosphere retention “A multiplanet system of super-Earths orbiting the brightest red dwarf star GJ 887”. <\/p>\n\n\n\n That earlier work also reported the same 51-day signal as a candidate planet.<\/p>\n\n\n\n The new paper builds on that by measuring the star\u2019s rotation at about 39 days and using that cycle to separate stellar noise from planet signals. A calm star today does not prove it was calm when it was young, so habitability remains uncertain. But cleaner data make follow-up observations more realistic.<\/p>\n\n\n\n Even at about 11 light-years away, GJ 887d is far beyond any near-term mission. At about 430,000 miles per hour, the Parker Solar Probe<\/a> would still need roughly 16,000 to 17,000 years to get there, based on its speed described in a recent Parker Solar Probe status update. That is why “nearby” planets are studied remotely.<\/p>\n\n\n\n Remote sensing means squeezing clues from light, such as heat changes over an orbit or, someday, direct images of the planet next to its star. Scientists also look for signs of an atmosphere, including clouds and strong greenhouse gases, even if they cannot yet read a full chemical fingerprint<\/a>. Slow, yes, but it is progress.<\/p>\n\n\n\n The next big question is straightforward. Does GJ 887d have a substantial atmosphere, and if it does, is it the kind that could support liquid water at the surface? Because the planet does not appear to pass in front of its star, many common atmosphere tests are harder.<\/p>\n\n\n\n Even so, proximity helps. A nearby, bright star gives future observatories more photons to work with, improving attempts at direct imaging or thermal measurements. If scientists can constrain temperature swings and reflectivity, they may narrow down whether this is a rocky world with weather or a thicker, Neptune-like planet.<\/p>\n\n\n\n For now, the discovery is less about claiming a living world and more about building a shortlist of the best targets. GJ 887d is close enough to keep showing up in telescope plans, and quiet enough to keep data cleaner than usual for a red dwarf system. That combination is rare.<\/p>\n\n\n\n The main study has been published in Astronomy & Astrophysics<\/em><\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" Astronomers have confirmed a planet called GJ 887d in the habitable zone of the nearby red dwarf star GJ 887. … <\/p>\nRead More: A potentially habitable super-Earth has been discovered just 10 light years away, and the big question of what might be waiting for us out there returns with a vengeance<\/a><\/h3>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n
How scientists spotted the wobble<\/h2>\n\n\n\n
What the habitable zone actually tells us<\/h2>\n\n\n\n
Why a quiet red dwarf matters<\/h2>\n\n\n\n
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![\"Artist's](\"https:\/\/www.ecoticias.com\/en\/wp-content\/uploads\/2026\/04\/super-earth-gj-887d-discovery-habitable-zone-1.jpg\" "\\"\\"")
Why we cannot travel there anytime soon<\/h2>\n\n\n\n
What comes next for GJ 887d<\/h2>\n\n\n\n
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