Further Evidence of the Planetary Nature of HD 95086 b from Gemini/NICI H-band Data

TL;DR

This study analyzes Gemini/NICI H-band data of HD 95086 to confirm the planetary nature of HD 95086 b, providing constraints on its properties and age, and comparing observational limits with planetary atmosphere models.

Contribution

It offers new H-band observational constraints on HD 95086 b, refines the system's age, and evaluates planetary atmosphere models against observational data.

Findings

H-band contrast reaches 12.7 mag at 5 sigma

Non-detection rules out foreground L/T dwarf hypothesis

Color limits are inconsistent with some planetary atmosphere models

Abstract

We present our analysis of the Gemini/NICI H-band data of HD 95086, following the discovery of the planet HD 95086 b in L'. The H-band data reach a contrast of 12.7 mag relative to the host star at 5 sigma levels in the location of HD 95086 b, and no point source is found. Our non-detection and H-L' color limit rules out the possibility that the object is a foreground L/T dwarf and that, if it is bound to HD 95086, it is a genuine planetary mass object. We estimate a new pre-main-sequence isochronal age for HD 95086 of 17+/-4 Myr, which is commensurate with previous mean age estimates for the Lower Cen-Crux subgroup. Adopting an age of 17 Myr, the color limit is inconsistent with the COND model, marginally consistent with the BT-SETTL model, and consistent with the DUSTY model.