NIRCam images of the disk around Beta Pictoris and the planet Beta Pictoris b
Jens Kammerer et al. / arXiv, 2024
The James Webb Infrared Space Telescope has captured direct images of the young superjupiter Beta Pictoris b. Observational data: the exoplanet has a dense cloudy atmosphere and there are no other bodies in the system except the already known two planets. A preprint of the work is available on arXiv.org.
The A-type star Beta Pictoris is known in exoplanetology; it was the first luminary for which a circumstellar disk was imaged, and one of the first for which a direct image of an exoplanet was obtained. The system contains two nested debris disks, one of which is tilted relative to the other, and two exogiants weighing several times the mass of Jupiter. The star is only 18.5 million years old, which, coupled with its 63 light-year distance from Earth, makes the system a prime target for studying the formation and early evolution of gas giants on scales similar to the Solar System.
A team of astronomers led by Jens Kammerer of the European Southern Observatory has published direct observations of the inner exoplanet Beta Pictoris b in the near-infrared using the James Webb NIRCam camera in high-contrast coronagraphy mode.
Beta Pictoris b has an effective temperature of 1700 kelvin, a radius of 1.4–1.5 that of Jupiter, and a mass of 9 Jupiter masses. The NIRCam observations are consistent with previous findings on the effective temperature and radius of the exoplanet, but the bolometric luminosity is lower than past results, and no restrictions on metallicity and C/O ratio could be obtained. The NIRCam data also supports a discrepancy between the exoplanet’s luminosity-related evolutionary model-derived mass and its dynamical mass (11.9 Jupiter masses). The atmospheric model that fits the observational data contains dense dust clouds.
The researchers also ruled out the presence of additional satellites of the star with a mass greater than one Jupiter mass beyond 40 astronomical units from the star and bodies with a mass greater than 0.05 Jupiter masses beyond 80 astronomical units from the star. Five additional sources were identified near the disk, but all turned out to be background stars or galaxies.
source: https://arxiv.org/abs/2405.18422