Delrez, Laetitia
CHEOPS consortium
2021-10-11
<p>Multi-transiting planetary systems around bright stars offer unique windows to comparative exoplanetology.<br>
Nu2 Lupi (HD 136352) is a naked-eye (V=5.8) Sun-like star that was discovered to host three low-mass<br>
planets with orbital periods of 11.6, 27.6, and 107.6 days via radial velocity monitoring with HARPS. The<br>
two inner planets (b and c) were recently found to transit by TESS, prompting us to follow up the system<br>
with CHEOPS. This led to the exciting discovery that the outer planet d is also transiting. With its bright<br>
Sun-like star, long period, and mild irradiation (~5.7 times the irradiation of Earth), Nu2 Lupi d unlocks<br>
a completely new region in the parameter space of exoplanets amenable to detailed characterization. We<br>
measured its radius and mass to be 2.56+/-0.09 R_Earth and 8.82+/-0.94 M_Earth, respectively, and refined<br>
the properties of all three planets: planet b likely has a rocky mostly dry composition, while planets c and d<br>
seem to have retained small hydrogen-helium envelopes and a possibly large water fraction. This diversity<br>
of planetary compositions makes the Nu2 Lupi system an excellent laboratory for testing formation and<br>
evolution models of low-mass planets.</p>
Contributed talk presented at the PLATO Mission Conference 2021.
https://doi.org/10.5281/zenodo.5566450
oai:zenodo.org:5566450
Zenodo
https://zenodo.org/communities/plato2021
https://doi.org/10.5281/zenodo.5566449
info:eu-repo/semantics/openAccess
Creative Commons Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/legalcode
Nature Astronomy, 5, 775-787, (2021-10-11)
Exploring the Nu2 Lupi system with CHEOPS
info:eu-repo/semantics/lecture