Astronomers have identified a faint planet orbiting the young star Beta Pictoris after a search lasting more than ten years. The discovery, made independently by two separate teams using different advanced telescopes, marks the dimmest exoplanet ever directly imaged.
One team, a collaboration between Scottish and German researchers, utilized the European Southern Observatory’s Very Large Telescope in Chile. They analyzed archived data over an extended period to confirm the planet's orbit. The other team, led by researchers in California, made their discovery using NASA’s James Webb Space Telescope. Both research groups published their findings in the Astrophysical Journal Letters.
The planet, designated Beta Pictoris d, was found serendipitously while each team was studying one of the star's two previously known companion planets. The newly discovered world is approximately 100 times fainter than its siblings and orbits farther out from its star. To avoid influencing each other's results, the teams kept their work secret from one another until after their respective discoveries.
"It was very much playing hide-and-seek for 11 years," said Markus Bonse of the European Southern Observatory, co-leader of the first team. "We’ve now built a picture of this planet, and we are very excited to see what more can be learned about it."
Beta Pictoris d is slightly larger than Jupiter and completes an orbit around its star every 91 years. The Beta Pictoris system is only about 20 million years old, making it very young in cosmic terms. Aidan Gibbs, who led the second team and is affiliated with the University of California San Diego, described the planet as likely resembling a much younger version of Jupiter. He noted that while giant planets appear to have formed, smaller, rocky planets could still be in the process of formation within the system.
"Beta Pictoris is probably our best look at a planetary system just after it has formed and is still in the process of stabilizing" from impacts by asteroids and comets, Gibbs stated.
The star Beta Pictoris is located in the southern constellation Pictor, approximately 63 light-years from Earth. A light-year is equivalent to nearly 6 trillion miles. While more than 6,000 exoplanets have been confirmed, fewer than 100 have been detected through direct imaging, according to NASA. Most exoplanets are discovered when they transit, or pass in front of, their host star, causing a slight dimming of its light.
