PDS 70 b: Evidence for a circumplanetary disc around the fIrst directly imaged protoplanet
Abstract
The observed properties of the major moons of Jupiter — and of other gas giants — have suggested that they formed within a circumplanetary disc. This prediction has been supported by theoretical calculations and numerical simulations of increasing complexity over the past few decades. Despite intensive search, circumplanetary discs had until now eluded detection. In this talk, I will present the first observational evidence for a circumplanetary disc, around recently imaged protoplanet PDS 70 b. Our detection is based on a new near-IR spectrum acquired with VLT/SINFONI. We tested several hypotheses (atmospheric emission alone, variable extinction, combination of atmospheric and circumplanetary disc emission) to explain the spectrum and show that models considering atmospheric emission alone consistently underpredict the longward portion of the spectrum. Our best fit is obtained with a combined atmospheric and circumplanetary disc model, with emission from the circumplanetary disc accounting for the apparent excess IR emission.
- Publication:
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AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- August 2019
- Bibcode:
- 2019ESS.....410105C