Hello and welcome! My name is Anton and in this video, we will talk about the first-ever direct image of two planets around a sun-like star.
Even though tens of directly imaged companions have been discovered in the past decades, the number of directly confirmed multi-planet systems is still small.
Dynamical analysis of these systems imposes important constraints on the formation mechanisms of these wide-orbit companions. As part of the Young Suns Exoplanet Survey (YSES) we report the detection of a second planetary-mass companion around the 17 Myr-old, solartype star TYC 8998-760-1 that is located in the Lower Centaurus Crux subgroup of the Scorpius-Centaurus association.
The companion has a projected physical separation of 320 au and several individual photometric measurements from 1.1 to 3.8 microns constrain a companion mass of 6±1 MJup, which is equivalent to a mass ratio of q = 0.57 ± 0.10% with respect to the primary.
With the previously detected 14 ± 3 MJup companions that are orbiting the primary at 160 au, TYC 8998-760-1 is the first directly-imaged multi-planet system that is detected around a young, solar analog.
We show that circular orbits are stable, but that mildly eccentric orbits for either/both components (e > 0.1) are chaotic on Gyr timescales, implying in-situ formation or a very specific ejection by an unseen third companion.
Due to the wide separations of the companions, TYC 8998-760-1 is an excellent system for spectroscopic and photometric follow-up with space-based observatories such as JWST.
Source: https://www.eso.org/public/archives/releases/sciencepapers/eso2011/eso2011a.pdf
