SDSS-IV MaStar: Determination of Stellar Parameters Using Bayesian Averaging
Year: 2026
Type: article
Abstract: We present the stellar parameters for 59,266 high-quality spectra of 24,130 unique stars from the MaNGA Stellar Library (MaStar) in the Sloan Digital Sky Survey (SDSS) Data Release 17 (DR17). The median signal-to noise ratio per pixel of the spectra is 96. We derive four stellar parameters, effective temperature ( T eff ), surface gravity ( log g ), metallicity ([M/H]), and α -enhancement ratio ([ α /M]), by comparing the data with BOSZ (ATLAS-9 based) and MARCS theoretical atmospheric models. We adopt a Bayesian method and use color and absolute magnitude derived from Gaia to select a subset of theoretical models for each star. We then perform full-spectrum fitting to estimate the likelihood of each model in the subset and then compute their likelihood-weighted mean parameters as the final parameters. We set stellar-parameter quality flags to facilitate the use of the derived stellar parameters. The MaStar stellar parameters derived herein span an effective temperature range of 2600 ≤ T eff ≤ 29,861 K, a surface gravity range of 0 ≤ log g ≤ 5.5 , a metallicity range of −4.9 ≤ [M/H] ≤ 1.0, and an α -abundance range of −0.98 ≤ [ α /M] ≤ 1.0. We compare these parameters with those from APOGEE and Gaia for stars in common, finding general consistency within the uncertainties. However, some artifacts and systematic differences are present, and we discuss their potential causes. These new stellar parameters are available through the MaStar SDSS-IV DR17 value-added catalog ( https://www.sdss4.org/dr17/mastar/mastar-stellar-parameters/ ).
Source: The Astrophysical Journal
Institutions: New York University Abu Dhabi, Chinese University of Hong Kong, Eötvös Loránd University, University of Portsmouth, University of Kentucky, New Mexico State University, University of Wisconsin–Madison, University of Cape Town, South African Astronomical Observatory, Lomonosov Moscow State University, The University of Texas at Austin, Vanderbilt University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: Smithsonian Institution, U.S. Department of Energy, Alfred P. Sloan Foundation, Yale University, Carnegie Institution of Washington, Vanderbilt University, Ohio State University, University of Washington, Johns Hopkins University, Carnegie Mellon University, University of Notre Dame, University of Portsmouth, New Mexico State University, New York University Abu Dhabi, York University, University of Oxford, National Natural Science Foundation of China, Ministério da Ciência, Tecnologia e Inovação, Chinese University of Hong Kong, Universidad Nacional Autónoma de México, Tamkeen, Max-Planck-Institut für Astrophysik, Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Canarias, Office of Science, University of Colorado Boulder, Leibniz-Gemeinschaft, Faculty of Science, Chinese University of Hong Kong, Lawrence Berkeley National Laboratory
OpenAlex ID: W7203686035