In-depth direct imaging and spectroscopic characterization of the young Solar System analog HD 95086

Abstract

Context. HD 95086 is a young nearby Solar System analog hosting a giant exoplanet orbiting at 57 au from the star between an inner and outer debris belt. The existence of additional planets has been suggested as the mechanism that maintains the broad cavity between the two belts. Aims. We present a dedicated monitoring of HD 95086 with the VLT/SPHERE instrument to refine the orbital and atmospheric properties of HD 95086 b, and to search for additional planets in this system. Methods. SPHERE observations, spread over ten epochs from 2015 to 2019 and including five new datasets, were used. Combined with archival observations, from VLT/NaCo (2012-2013) and Gemini/GPI (2013-2016), the extended set of astrometric measurements allowed us to refine the orbital properties of HD 95086 b. We also investigated the spectral properties and the presence of a circumplanetary disk around HD 95086 b by using the special fitting tool exploring the diversity of several atmospheric models. In addition, we improved our detection limits in order to search for a putative planet c via the K-Stacker algorithm. Results. We extracted for the first time the JH low-resolution spectrum of HD 95086 b by stacking the six best epochs, and confirm its very red spectral energy distribution. Combined with additional datasets from GPI and NaCo, our analysis indicates that this very red color can be explained by the presence of a circumplanetary disk around planet b, with a range of high-temperature solutions (1400-1600 K) and significant extinction (A V 10 mag), or by a super-solar metallicity atmosphere with lower temperatures (800-1300 K), and small to medium amount of extinction (A V 10 mag). We do not find any robust candidates for planet c, but give updated constraints on its potential mass and location.

The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope. IV. Aperture Masking Interferometry

“…NIRISS Guaranteed Time Observations (GTO) program 1200 will explore the inner architecture of 3 systems with known planets or debris disks, namely HR 8799 (Marois et al 2008(Marois et al , 2010De Rosa et al 2016;Wahhaj et al 2021;Zurlo et al 2022), HD 95086 (Rameau et al 2013a(Rameau et al , 2013b(Rameau et al , 2016Su et al 2015;Desgrange et al 2022) and HD 115600 (Currie et al 2015;Gibbs et al 2019). In all these systems, the structure of the disk or the orbital configuration hint toward the presence of yet undetected companion(s) at short separations.…”

Simulated performance of the molecular mapping for young giant exoplanets with the Medium Resolution Spectrometer of JWST/MIRI

“…Chauvin et al (2018) found that its near-infrared spectral energy distribution is well-fitted by spectral models of dusty and/or young L7-L9 dwarfs. Here, we aim at testing the two scenarios highlighted in Desgrange et al (2022) using SPHERE observations combined with archival observations from VLT/NaCo and Gemini/GPI. These scenarios indicate that the color of the planet can be explained by the presence of a circumplanetary disk around planet b, with a range of high-temperature solutions (1400-1600 K) and significant extinction, or by a super-solar metallicity atmosphere but lower temperatures (800-1300 K), and small to medium amount of extinction.…”

Polarized Signatures of a Habitable World: Comparing Models of an Exoplanet Earth with Visible and Near-infrared Earthshine Spectra

“…Currently, transit spectroscopy and the direct detection of planetary flux are the most widely used techniques for performing these characterizations. While proven successful for the gaseous giant exoplanets at very short (transiting; e.g., Line et al 2013;Sing et al 2016) or very wide (imaging; e.g., Marois et al 2008;Desgrange, C. et al 2022) orbital distances, Earth-sized exoplanets around Sun-like stars are more challenging and introduce a number of issues. In transit, the smaller planetary sizes and wider orbital distances of habitable terrestrial planets compared to gaseous giant planets mean that they only block a minuscule fraction of their host star upon transiting (e.g., Kaltenegger & Traub 2009;Pallé et al 2011).…”