The Latest: Two liveable “super-Earths” and one “cold Neptune”

BEIJING, Jan. 17 (Xinhua) — Astronomers have recently discovered two potentially life-supporting exoplanets, as well as a strange, record-breaking “cold Neptune,” according to the U.S. space website.

  The image shows the latest discovery of the exoplanet GJ180 d, the closest temperature to Earth, which is suitable for super-Earths and is not locked in to the host star by tides, making it more likely to have life forms.

Two livable “super-Earths”

The two habitable exoplanets orbit the red dwarfs GJ229A and GJ180, respectively, 19 light-years and 39 light-years from Earth, and the Milky Way disk structure is about 100,000 light-years in diameter, compared with the Red Dwarfs GJ229A and GJ180, which were not far from Earth, and previously observed the closest stars to the sun are neighboring stars. , about 4.2 light-years.

Red dwarfs, which make up about 70 percent of the milky galaxy’s stars, are smaller and darker than the sun, so the “habitable zone” of these stars — the orbital distance range of planets with liquid water on the surface — is closer to the star-planetary position in the solar system.

In fact, the red dwarf’s habitable zone is special, with habitable planets in a tidal lock state, meaning that always one side faces the red dwarf, just as the moon always shows its near-Earth side toward earth, and tidal locking is not good for livability, although livable planets may have a thick atmosphere that releases global heat and relieves extreme temperatures. But the habitable planet is always on one side on a hot day and the other on a cold night.

The image shows the newly discovered exoplanet GJ229Ac, which orbits the binary system, one of which is a brown dwarf.

The two newly discovered habitable exoplanets, named GJ180 d and GJ229A c respectively, orbit very far from the main star to avoid tidal lock-in, and the habitable planet GJ180 d, which has multiple cosmic records, is the closest, moderately temperatured super-Earth, which is not in tidal lock-in with the main star which will increase its chances of sustaining life.

GJ180 d is a “super-Earth” with a slightly larger mass than Earth, about 7.5 times the mass of Earth, and GJ229A c is also a “super-Earth”, which is at least 7.9 times the mass of Earth. GJ180 d it takes 106 Earth days to orbit the main star, and GJ229A c to orbit the main star 122 Earth days. The scientists published the study in the recent journal Astrophysics Supplement.

GJ229A c is located in a binary system that includes a red dwarf star and a brown dwarf (named GJ229B), a peculiar celestial body larger than a gas giant planet, but its core cannot react to fusion, and is therefore named “unqualified star”.

As the name GJ180 d is, it is not the only known planet in the star system, and astronomers have previously found two planets orbiting the host star: GJ180 b and GJ180 c.

Astronomers don’t know much about the two newly discovered exoplanets, pointing out that they will be the best space-watching targets in the future, as they are relatively close to the solar system. The latest discovery will open up the possibility for the next generation of telescopes to directly observe exoplanets, with the goal of studying the existence of life on planets orbiting nearby stars.

“Cold Neptune”

Astronomers have discovered a “cold Neptune” – GJ 433 d , which doesn’t seem to be the best candidate for livable life, but it’s a very different planet, at least 4.9 times the mass of Earth, orbiting a dark red dwarf star 29.5 light-years from Earth.

GJ 433 d is by far the closest, weirdest, coldest Neptune planet to be observed, and it is a very good follow-up study target, including direct imaging observations.

The latest findings are reported lying in the analysis of 33 nearby red dwarf smuses collected by the European Southern Observatory between 2000 and 2007, which reveal the motion of stars produced by the gravitational pull of orbiting planets. (Ye Ding Cheng)