Condensation Clouds in Substellar Atmospheres with Virga

TL;DR

Virga is an open-source Python cloud model for substellar atmospheres, building on previous models, with updated features, benchmarking, and ongoing development to aid research on exoplanets and brown dwarfs.

Contribution

The paper introduces Virga v1, an improved, open-source cloud model for substellar atmospheres, expanding on the Ackerman & Marley framework with new features and community engagement.

Findings

Successfully benchmarked Virga against literature results

Reproduced SiO2 cloud detection in WASP-17 b

Modeled brown dwarf cloud series Diamondback-Sonora

Abstract

Here we present an open-source cloud model for substellar atmospheres, called Virga. The Virga-v0 series has already been widely adopted in the literature. It is written in Python and has heritage from the Ackerman & Marley (2001) model (often referred to as eddysed), used to study clouds on both exoplanets and brown dwarfs. In the development of the official Virga-v1 we have retained all the original functionality of eddysed and updated/expanded several components including the back-end optical constants data, calculations of the Mie properties, available condensate species, saturation vapor pressure curves and formalism for fall speeds calculations. Here we benchmark Virga by reproducing key results in the literature, including the SiO2 cloud detection in WASP-17 b and the brown dwarf Diamondback-Sonora model series. Development of Virga is ongoing, with future versions already planned and ready for release. We encourage community feedback and collaborations within the GitHub code repository.