Jun 25, 2020 - Science

Newfound exoplanets aren't too far from Earth

Artist’s impression of the multiplanetary system of Super Earths orbiting Gliese 887.
Artist’s impression of the multiplanetary system of planets orbiting GJ 887. Credit: Mark Garlick

A small star only 11 light-years from our solar system may play host to a clutch of planets, one of which might be suitable for life.

Why it matters: Because this star and its planets are relatively nearby, they're great candidates for follow-up studies that could one day allow scientists to peer into their atmospheres and figure out exactly what they're made of.

What they found: The star — named GJ 887 — is orbited by at least two planets that are just slightly larger than Earth, according to a new study in the journal Science.

  • A possible third world may orbit the star every 50 days and could be in its "habitable zone," the orbit around a star where a planet could support liquid water, potentially upping the odds for life.
  • However, follow-up studies need to confirm there is, in fact, a third promising planet orbiting the star.
  • The study's authors were able to detect the planets' small gravitational tugs on their star as they observed the star over the course of three months.

The intrigue: The scientists behind the study were also surprised that the relatively bright red dwarf star is quiet.

  • Usually, exoplanets — worlds orbiting stars other than the Sun — circling red dwarfs aren't thought to be good candidates to host life because these stars, which are smaller than the Sun, tend to shoot out massive, irradiating flares.
  • This star, however, seems to be pretty even-keeled.
  • "It's quiet in the sense that it doesn't have these dark star spots like we see on the Sun, or it doesn't have these very energetic outbursts that we also see on the Sun," Sandra Jeffers, one of the authors of the new study told Axios.

Yes, but: While the star seems quiet now, it may have been active in the past when it was younger, potentially hurting the odds that the planets around the star could host life.

What's next: Scientists are on the verge of having the tools they need to study worlds orbiting distant stars more thoroughly than they have in the past.

  • The James Webb Space Telescope — expected to launch sometime next year — will be able to investigate the compositions of atmospheres of some alien planets, giving scientists a better sense of what types of worlds are habitable.
  • "We've really started valuing these bright systems so that we can do all of this much more detailed analysis of the atmospheres of these planets," exoplanet researcher Jessie Christiansen, who wasn't affiliated with the study, told Axios.

The bottom line: The planets surround GJ 887 are further proof that our galaxy is teeming with worlds circling nearby and distant stars.

  • "All of the nearby stars to us have got planets around them," Christiansen said.
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