What might the artistic concept of a gas giant in orbit around Alpha Centauri A resemble?
ESA/Webb Copyright: NASA, ESA, CSA, STSCI, R.
A massive planet comparable to Saturn is potentially identified orbiting a sun-like star in our nearest stellar system, Alpha Centauri.
Located just four light-years from Earth, Alpha Centauri is the closest star system to us, comprising three stars: Alpha Centauri A, Alpha Centauri B, and the Red Dwarf Star Proxima Centauri. Scientists have long speculated that planets akin to those in our solar system could exist in such systems, and whether planets can reside at distances similar to our Sun’s “habitable zone” around binary stars has been a matter of intrigue. “These stars are very bright, relatively close, and move quickly across the sky,” mentions Charles Baichman from Caltech in a statement.
Recent observations gathered by the James Webb Space Telescope (JWST) mid-infrared instrument suggest that a gas giant possibly as substantial as Saturn is orbiting the sun-like star, Alpha Centauri A. This discovery has come as a surprise. “Webb was specifically designed to identify the most distant galaxies, not exoplanets,” remarked Beichman, underscoring that such an identification must be meticulously coordinated through numerous observations, evaluations, and computer simulations, which “can yield remarkable insights.”
While previous methodologies for detecting planets relied on indirect measurements, the JWST executed a “more ambitious” approach by actually gathering light from potential planets, according to Alan Boss of Carnegie Science in Washington, DC, who was not involved in this particular study. Nevertheless, visibility of the potential planets was lost in subsequent observations.
“We’re encountering a case of a disappearing planet!” exclaimed Aniket Sanghi, also at Caltech, in a statement. The research team ran simulations of millions of possible trajectories to solve this conundrum, determining that “in half of the possible simulated orbits, the planet would have been too close to the star, making it undetectable by Webb in both February and April 2025,” he said.
As a gas giant, this planet wouldn’t support life as we know it. However, if this finding is validated, it could significantly enhance our understanding of planet formation around stars. “The mere existence of two closely situated stars within a stellar system will challenge our comprehension of how planets form, survive, and evolve under such chaotic circumstances,” Sangi pointed out. “This is also crucial for Earth, as it is our closest neighbor, beside the giant planets in our solar system, with a temperature and age somewhat akin to Earth.”
This revelation has been documented in two accepted papers for publication in Astrophysics Letters.
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Source: www.newscientist.com
