Relation between Brown Dwarfs and Exoplanets

TL;DR

This study introduces a new diagnostic diagram to compare Brown Dwarfs and exoplanets, revealing potential similarities in their structures and suggesting they may share common formation processes involving liquid metallic hydrogen.

Contribution

The paper presents a novel BGP-distance diagnostic diagram and analyzes mass-radius relations to distinguish and compare the structures of Brown Dwarfs and exoplanets.

Findings

Identified a common BGP range for BDs and exoplanets.

Different behaviors in mass-radius relations across BGP ranges.

Evidence suggesting similar structures dominated by liquid metallic hydrogen.

Abstract

One of the most debated subjects in Astronomy since the discovery of exoplanets is how can we distinguish the most massive of such objects from very-low mass stars like Brown Dwarfs (BDs)? We have been looking for evidences of a difference in physical characteristics that could be related to different formation processes. Using a new diagnostic diagram that compares the baryonic gravitational potential (BGP) with the distances from their host stars, we have classified a sample of 355 well-studied exoplanets according to their possible structures. We have then compared the exoplanets to a sample of 87 confirmed BDs, identifying a range in BGP that could be common to both objects. By analyzing the mass-radius relations (MRR) of the exoplanets and BDs in those different BGP ranges, we were able to distinguish different characteristic behaviors. By comparing with models in the literature, our results suggest that BDs and massive exoplanets might have similar structures dominated by liquid metallic hydrogen (LMH).