Séminaire IPAG

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Results and prospects for direct imaging of exoplanets and brown dwarfs detected in astrometry

jeudi 13 octobre 2022 - 11h00

Anne-Lise Maire - IPAG
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Direct imaging surveys for giant exoplanets around hundreds of young and nearby stars have shown that giant planets in wide orbits are rare. These surveys used selection criteria on the youth, the probability to detect a planet, or the presence of IR excess but no criteria on the indirect evidence of planets from other exoplanet detection techniques due to a small overlap. Radial velocity surveys are biased toward mature exoplanets whereas astrometric searches have shown low sensitivity to planets. Gaia is about to revolutionize the field with the first all-sky census of gas giant exoplanets and brown dwarfs at a few au from stars expected in >2025. I will first discuss studies which used Gaia DR2 and EDR3 data with Hipparcos data to infer the presence of long-period substellar companions. The first surveys have show promising detection rates of ~30%. I will also discuss first imaging attempts for closer-in companions using Gaia DR3. The limited baseline of Gaia DR3 makes this challenging even for the high angular resolution of VLTI/GRAVITY. The full Gaia data and direct imaging instruments at higher resolution and sensitivity will be required to advance the field.

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Hôtes : Mickael Bonnefoy

Salle Manuel Forestini, 414 rue de la piscine, 38400 Saint Martin d'Hères