• A super-Earth has been discovered just 10 light-years away

    From a425couple@a425couple@hotmail.com to alt.astronomy,rec.aviation.military on Mon May 4 08:39:33 2026
    From Newsgroup: alt.astronomy

    from https://www.ecoticias.com/en/a-super-earth-has-been-discovered-just-10-light-years-away-which-could-harbor-an-atmosphere-and-water-but-reaching-it-with-current-technology-would-take-us-about-15000-years/31607/#google_vignette

    A super-Earth has been discovered just 10 light-years away, which could
    harbor an atmosphere and water, but reaching it with current technology
    would take us about 15,000 years
    Image Autor
    By ECONEWS
    Published On: May 3, 2026 at 6:30 PM
    Follow Us
    Artist's impression of a rocky super-Earth exoplanet orbiting a red
    dwarf star in the GJ 887 system.

    Astronomers have confirmed a planet called GJ 887d in the habitable zone
    of the nearby red dwarf star GJ 887. It circles every 50.8 days and has
    at least six times EarthrCOs mass. That makes it one of the closest known worlds where liquid water might be possible, if it has a stable atmosphere.

    So is it close? In space terms, yes, but it is still about 63 trillion
    miles away, so this is a telescope story, not a travel story. The
    takeaway is that GJ 887d is now a more solid target for future
    atmosphere searches.

    A calm star with a busy planetary system
    GJ 887, also called Gliese 887 and Lacaille 9352, is a cool rCLred dwarfrCY that puts out only a few percent of the SunrCOs light. That low energy
    shifts the habitable zone inward. Planets can orbit quickly and still be potentially temperate.

    Read 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
    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.

    How scientists spotted the wobble
    The work comes from an international team led by astronomer C. Hartogh
    at the Institute of Astrophysics and Geophysics at the University of G||ttingen, with partners including the University of St Andrews and
    ItalyrCOs National Institute for Astrophysics.

    Their paper, rCLRedDots: multiplanet system around M dwarf GJ 887 in the
    solar neighborhood,rCY reanalyzed existing observations and added new ones
    to test whether the 51-day signal was real.


    They used the radial velocity method, which detects a planet by
    measuring a starrCOs tiny back-and-forth motion.

    The signal was measured with the HARPS spectrograph 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 rCLGaussian processrCY to subtract the starrCOs own noise.

    What the habitable zone actually tells us
    NASA defines a habitable zone as rCLthe distance from a star at which
    liquid water could exist on orbiting planetsrCO surfaces,rCY sometimes
    called the rCLGoldilocks zone.rCY That definition is in this official habitable zone guide. It is a useful filter, but it is not a guarantee
    of oceans or biology.

    For GJ 887d, the studyrCOs basic temperature estimate without atmospheric warming is below freezing by Earth standards.


    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 EarthrCOs mass, GJ 887d could
    be rocky or it could have a deep, gas-rich atmosphere.

    Why a quiet red dwarf matters
    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 report highlighted its unusually low activity
    as good news for atmosphere retention rCLA multiplanet system of
    super-Earths orbiting the brightest red dwarf star GJ 887rCY.

    Read More: Malaysia replaced streetlights with roads that glow in the
    dark, but this futuristic idearCowhich promised to revolutionize night drivingrCoended up running into a very down-to-earth problem
    That earlier work also reported the same 51-day signal as a candidate
    planet.

    The new paper builds on that by measuring the starrCOs 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.

    Artist's impression of a rocky super-Earth exoplanet orbiting a red
    dwarf star in the GJ 887 system.
    Astronomers have confirmed that GJ 887d sits in the rCLGoldilocks zonerCY of its star, making it one of the most promising candidates for future
    atmosphere and water searches.
    Why we cannot travel there anytime soon
    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 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 rCLnearbyrCY planets are studied remotely.

    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. Slow, yes, but it is progress.

    What comes next for GJ 887d
    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.

    Read More: Goodbye to the 24-hour day: from this date onwards, days on
    Earth will last 25 hours
    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.

    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.

    The main study has been published in Astronomy & Astrophysics.


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  • From Jim Wilkins@muratlanne@gmail.com to alt.astronomy,rec.aviation.military on Mon May 4 13:38:08 2026
    From Newsgroup: alt.astronomy

    "a425couple" wrote in message news:W43KR.601715$Zve6.76451@fx18.iad...

    from https://www.ecoticias.com/en/a-super-earth-has-been-discovered-just-10-light-years-away-which-could-harbor-an-atmosphere-and-water-but-reaching-it-with-current-technology-would-take-us-about-15000-years/31607/#google_vignette
    ...
    They used the radial velocity method, which detects a planet by
    measuring a starrCOs tiny back-and-forth motion.

    The signal was measured with the HARPS spectrograph and the ESPRESSO spectrograph, instruments operated in Chile by the European Southern Observatory.

    ------------------------------
    In college I learned how scientific instruments work, and have tried to keep up with advances.

    These spectroscopic instruments which measure radial velocity (toward/away) from Doppler shift can detect a change of 3 feet per second, 2 miles per
    hour. A star and planet orbit around their combined center of gravity, the star is slightly offset away from the orbiting planet, which gives the measurable wobble in the star's radial velocity and spectral lines.

    https://en.wikipedia.org/wiki/Fraunhofer_lines https://phys.libretexts.org/Bookshelves/University_Physics/University_Physics_(OpenStax)/University_Physics_III_-_Optics_and_Modern_Physics_(OpenStax)/05%3A__Relativity/5.08%3A_Doppler_Effect_for_Light

    For the Earth and Sun the radial velocity variation observed from another
    star would be around 4 inches per second, extremely difficult to measure
    even in the lab.

    https://www.jpl.nasa.gov/news/tiny-measurement-gives-big-boost-to-planet-hunt/ But...
    https://en.wikipedia.org/wiki/Space_Interferometry_Mission

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