HD 169142 b, third protoplanet confirmed so far | Urania

An international science team has published the results of data analysis from the SPHERE instrument, which confirm the existence of a new protoplanet.

Planets are made up of clusters of matter discs About newborn stars. When a planet is still forming, or accumulating matter, it’s called protoplanet. So far, only two protoplanets have been definitively identified as such, PDS 70 bis, and both orbit the star PDS 70 (as already mentioned). This number was increased to three with the discovery and confirmation of the surrounding gas and dust disk HD 169142a star of 374 degrees light years from U.S Solar System. We used notes from the instrument sphere Taken on the star HD 169142, which was observed several times between 2015 and 2019. explains Ian Hammond, a researcher at Monash University (Australia). Because we expect planets to be hot when they form, the telescope took infrared images of HD 169142 to search for the heat signature of their formation. Thanks to these data, it was possible to confirm the existence of the planet HD 169142 babout 37 Astronomical units from its star – just beyond the orbit of Neptune. More recently in 2019, a research team led by R.

The various images, taken with the SPHERE instrument between 2015 and 2019, reveal a compact source moving in time as would be expected for a planet orbiting its star by 37 AU. All SPHERE datasets were analyzed using state-of-the-art image processing tools developed by the PSILab team at the University of Liège. The last set of data included in our study, obtained in 2019, is essential to confirm the planet’s motion. explains Valentin Christians, FRS-FNRS researcher at PSILab (STAR ​​Institute/Faculty of Sciences) at ULiège. This dataset has not yet been published.

The new images also confirm that the planet must have etched an annular crack in the disk – as predicted by models. This gap is clearly visible in observations of the disk’s polarized light. In the infrared, we can also see the spiral arm of the planet-born disk and visible in its wake, suggesting that other protoplanetary disks with spirals may also contain undetected planets. Hammond said. The images of the polarized light, as well as the infrared spectrum measured by the research team, indicate that the planet is buried in a large amount of dust accumulated from the protoplanetary disk. This dust can take the form of a disk around the planet, a small disk that forms around the planet itself, which in turn can form moons. This important discovery shows that planets can be detected by direct imaging even at a very early stage of their formation.

Over the past 10 years, there have been many false positives among the detected planetary configurations Valentine Christians said. Apart from the PDS 70 protoplanets, the status of other candidates is still hotly debated in the scientific community. The protoplanets of DH 169142 b appear to have different properties than the protoplanets of PDS 70, which is very interesting. We seem to have caught it at a smaller stage of its formation and development, when it is still either completely buried or surrounded by a lot of dust. Given the very small number of planet formations confirmed so far, the discovery and observations of this source should give us a better understanding of how planets, especially giant planets like Jupiter, form.

Further protoplanetary characterization and independent confirmation through future observations can be obtained using James Webb Space Telescope. JWST’s high infrared sensitivity should already allow scientists to detect heat emissions from hot dust around the planet.

Test results have been left published 4 April 2023 in Monthly Notices of the Royal Astronomical Society (MNRAS).

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Agnes Nowak

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Source: UNIVERSITY DE LIÈGE

Pictured: An image of the HD 169142 system showing signals from the formation of the planet HD 169142 b, as well as a spiral arm resulting from the dynamic interaction between the planet and its host disk. Source: VLT / SPHERE