# The MESAS Project: Long wavelength follow-up observations of Sirius A

## TL;DR

This paper presents new long-wavelength observations of Sirius A using ALMA, GBT, and VLA, enhancing stellar atmosphere models and aiding in the study of circumstellar debris.

## Contribution

It provides the first comprehensive multi-telescope observations of Sirius A at 1.4 to 9.0 mm, validating stellar atmosphere models at these wavelengths.

## Key findings

- Observations are consistent with PHOENIX models.
- Data span from 1.4 to 9.0 millimeters.
- Supports modeling of stellar and circumstellar environments.

## Abstract

Modeling the submillimeter to centimeter emission of stars is challenging due to a lack of sensitive observations at these long wavelengths. We launched an ongoing campaign to obtain new observations entitled Measuring the Emission of Stellar Atmospheres at Submillimeter/millimeter wavelengths (MESAS). Here we present ALMA, GBT, and VLA observations of Sirius A, the closest main-sequence A-type star, that span from 1.4 to 9.0 millimeters. These observations complement our previous millimeter data on Sirius A and are entirely consistent with the PHOENIX stellar atmosphere models constructed to explain them. We note that accurate models of long wavelength emission from stars are essential not only to understand fundamental stellar processes, but also to determine the presence of dusty debris in spatially unresolved observations of circumstellar disks.