Calendar

Avr
30
ven
Romane le Gal – Chemistry of planet-forming disks @ Zoom
Avr 30 @ 11 h 00 min – 12 h 00 min
Séminaire

Title: Unraveling the chemistry of planet-forming disks in the ALMA era
Speaker: Dr. Romane Le Gal (CNES post-doctoral researcher, IRAP)

Abstract: Over the past decades, questions on the origins and prevalence of life on planets have shifted from metaphysical questions to hot research topics in astrophysics. The latest generation of high-sensitivity telescopes has provided access to the cradles of star and planet formation at unprecedented spatial and spectral resolutions, making it possible to study the chemical evolution of interstellar matter from molecular clouds to forming planetary systems. A key question in this context is to assess how much of the pre-stellar molecular composition survives and becomes incorporated into planets. Or, conversely, how much nascent planets are affected by chemical reprocessing that occur in their birth environments, i.e. in planet-forming disks around young stars. Indeed, these disks are exposed to energetic radiations and undergo strong dynamical phenomena such as planet formation, which may substantially alter their chemical inventory. In this talk I will present how my research combines observations and astrochemical modeling fed by theoretical and experimental studies to 1) better understand and characterize the chemistry of these disks, 2) start disentangling between chemical inheritance and chemical reprocessing in planet-forming disks, and 3) identify chemical signatures of planet formation.

Mai
4
mar
Vincent Hue – Exploration of the Jovian Outer Magnetosphere with Juno @ Zoom
Mai 4 @ 15 h 00 min – 16 h 00 min
Séminaire

Title: Exploration of the Jovian Outer Magnetosphere with Juno
Speaker: Vincent Hue (Research Scientist – Southwest Research Institute)

Abstract: Jupiter’s magnificent auroral lightshow is a direct manifestation of its strong magnetic field, which couples its magnetospheric plasma and ionosphere. In the ultraviolet spectral range, the Jovian auroras are highly structured, and reflect the numerous processes occurring throughout the magnetosphere. Since July 2016, NASA’s New Frontiers mission Juno performs in-situ and remote sensing measurements from within the Jovian magnetosphere. In this talk, we discuss the main auroral regions with a particular emphasis on the polar auroral regions, linked to the outermost region of Jupiter’s magnetosphere and possibly the solar wind. These are the most highly dynamic components of the Jovian auroras, often exhibiting flares evolving over short timescales. We present a new type of auroral feature recently discovered by the Ultraviolet Spectrograph on Juno (Juno-UVS), which consists in circular expanding UV-emission, and discuss their potential origin.