The Gaia All-Sky Stellar Parameters Service (GASPS)

TL;DR

GASPS automates the fitting of spectral energy distributions for over 240 million Gaia stars, providing high-precision stellar parameters like temperature and luminosity, enabling advanced galactic and interstellar studies.

Contribution

This work introduces a large-scale, automated SED fitting service for Gaia DR3 data, significantly expanding the number of stars with derived stellar parameters.

Findings

High-quality temperature and luminosity estimates for 240 million stars

Demonstrated potential for stellar classification and interstellar medium mapping

Showcased the utility of ultraviolet and infrared excess analysis

Abstract

Temperature and luminosity are the two key diagnostics of a star, yet these cannot come directly from survey data, but must be imputed by comparing those data to models. SED fitting offers a high-precision method to obtain both parameters for stars where both their distance and extinction are well known. The recent publication of many all-sky or large-area surveys coincides the publication of parallaxes and 3D extinction cubes from the Gaia satellite, making it possible to perform SED fitting of truly large ($>10^8$) numbers of Galactic stars for the first time. The analysis of this data requires a high level of automation. Here, we describe the ongoing Gaia All-Sky Stellar Parameters Service (GASPS): the fitting of 240 million SEDs from Gaia DR3 and the extraction of temperatures and luminosities for the corresponding stars using the PySSED code. We demonstrate the quality of the initial results, and the promise that these data show, from wavelength-specific information such as the ultraviolet and infrared excess of each star, to stellar classification, to expansion of the project beyond our own Galaxy, and mineralogical mapping of the Milky Way's interstellar medium.