HD 169142 b is only the third exoplanet to have been imaged during formation.
For only the third time in history a distant alien planet many light-years away from Earth has been photographed as it’s being formed.
Researchers at Monash University in Melbourne, Australia this week published in the Monthly Notices of the Royal Astronomical Society new images of what astronomers call a protoplanet forming in a star system 350 light-years distant.
HD 169142 is a star in the constellation Sagittarius and it’s surrounded by a disc of dense gas and dust. Suspected since 2014 by astronomers in previous research, the images reveal that a young newly formed star exists inside.
A study led by Monash University astronomers has published new near-infrared images of the HD 169142 … [+]
The planet, called HD 169142 b, was imaged directly using the European Southern Observatory’s Very Large Telescope (VLT) in Chile, which can detect near-infrared light as heat.
This image (above)—captured by an instrument called SPHERE attached to the giant telescope—represents four years. It was taken between 2015 and 2019 and imaged despite being buried in dust.
The planet, which this image confirms to be in the process of forming, lies about the same distance from its star as Neptune does from our Sun. A star needs to be well away from its parent stars to be directly imaged like this. However, only two other exoplanets have been imaged directly in the same fashion—PDS 70 b and c, which both orbit the star PDS 70.
“We successfully detected a protoplanet at approximately 37 au from the star in all four observations, and it orbits its host star at the expected velocity defined by Kepler’s third law,” said Iain Hammond, lead study author PhD candidate from the Monash University School of Physics and Astronomy.
Kepler’s third law states that the farther a planet is from its star the slower it will orbit.
The four 8.2 meter optical telescopes of the Very Large Telescope (VLT) work as the sun sets over … [+]
Reflecting visible light while emitting its own infrared radiation, HD 169142 b was found to have carved a gap in the disc around the star. “We expect planets to be hot during their formation, and the telescope observed HD 169142 in the near infrared to search for signatures of planet formation around the star,” said Hammond.
“In the near-infrared we can see a spiral arm being excited in the disc by the planet, which strongly suggests other protoplanetary discs that contain similar spirals could host yet-undiscovered planets.”
It’s also suspected that the protoplanetary disc could host moons. HD 169142 b should now be studied by the James Webb Space Telescope, said the researchers.
Wishing you clear skies and wide eyes.
