Large-scale stellar spectroscopic surveys are generating extensive data on stellar parameters, crucial for understanding the Milky Way structure and evolution. However, accuracy is still a concern: current surveys rely on few dozens F-G-K benchmark stars for homogenization. As a consequence, survey products can present inconsistencies, leading to varying abundance trends and zero-points across surveys, introducing biases in the resulting data. This problem also affects the training samples of machine learning algorithms.

To address these problems, representatives from SDSS-V (Sloan Digital Sky Survey), WEAVE (WHT Enhanced Area Velocity Explorer, Spain), DESI (Dark Energy Spectroscopic Instrument, USA), and 4MOST (4-Meter Multi-Object Spectroscopic Telescope) have agreed to create a cross-survey calibrators catalog. This catalog broadens the parameter space of calibrators beyond the traditional F-G-K benchmark stars and it includes about 100,000 targets. These targets encompass a wide range of stellar classes: e.g., O- and B- type stars, binaries, young stars, open and globular clusters, red giants with asteroseismology, Cepheids, RR Lyrae, Asymptotic Giant Branch and Carbon stars. The targets are mainly distributed along a 60 deg wide stripe on the celestial equator to ensure observability from both hemispheres.

SDSS-V, DESI, and WEAVE spectroscopic surveys have begun using this expanded catalog, and 4MOST will join once its science verification phase commences. The data and spectra will be shared among these projects, demonstrating a commitment to cooperation and consistency in stellar data collection. The resulting reference catalogue will have a significant importance for present and future spectroscopic surveys.

Programme

Invited speakers

Scientific organisers

M. Valentini, Leibniz-Institute für Astrophysik Potsdam (AIP), Germany G. Guiglion, Zentrum für Astronomie der Universität Heidelberg, Germany P. Jofre, Instituto de Estudio Astrofísicos, UDP, Chile S. Lucatello, INAF - Osservatorio Astronomico di Padova, Italy K. Cunha ,University of Arizona, USA

Contact

Marica Valentini: mvalentini @ aip.de