The S-PLUS Ultra-Short Survey: First data release^★

¹ Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, ul. Bartycka 18, 00-716 Warsaw, Poland
² Universidade de São Paulo, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Departamento de Astronomia, SP 05508-090, São Paulo, Brazil
³ NSF NOIRLab, Tucson, AZ 85719, USA
⁴ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁵ Department of Physics and Astronomy and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556, USA
⁶ Institut de Ciéncies del Cosmos (ICCUB), Universitat de Barcelona (UB), Martí i Franqués, 1, 08028 Barcelona, Spain
⁷ Visiting Fellow, Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK
⁸ INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
⁹ Universidade Federal do Rio de Janeiro, Observatório do Valongo, Lad. Pedro Antônio 43, 20080-090 Rio de Janeiro, Brazil
¹⁰ Department of Astronomy & Steward Observatory, University of Arizona, Tucson, AZ 85721, USA
¹¹ Observatório Nacional, MCTI, Rua Gal. José Cristino 77, Rio de Janeiro 20921-400, RJ, Brazil
¹² Instituto de Astrofísica de Andalucía, CSIC, Apt 3004, 18080 Granada, Spain
¹³ Instituto de Física Aplicada a las Ciencias y las Tecnologías, Universidad de Alicante, San Vicent del Raspeig, 03080 Alicante, Spain
¹⁴ Universidade Presbiteriana Mackenzie, Rua da Consolacão, 930, São Paulo 01302-907, SP, Brazil
¹⁵ GMTO Corporation 465 N. Halstead Street, Suite 250, Pasadena, CA 91107, USA
¹⁶ Rubin Observatory Project Office, 950 N. Cherry Ave., Tucson, AZ 85719, USA
¹⁷ Departamento de Física, Universidade Federal de Santa Catarina, Florianópolis, SC 88040-900, Brazil

^★★ Corresponding author; hperottoni@gmail.com

Received: 30 November 2023
Accepted: 26 April 2024

Abstract

Context. This paper presents the first public data release of the S-PLUS Ultra-Short Survey (USS), a photometric survey with short exposure times, covering approximately 9300 deg² of the Southern sky. The USS utilizes the Javalambre 12-band magnitude system, including narrow, medium, and broad-band filters targeting prominent stellar spectral features. The primary objective of the USS is to identify bright, extremely metal-poor (EMP; [Fe/H] ≤ −3) and ultra-metal-poor (UMP; [Fe/H] ≤ −4) stars for further analysis using medium- and high-resolution spectroscopy.

Aims. This paper provides an overview of the survey observations, calibration method, data quality, and data products. Additionally, it presents the selection of EMP and UMP candidates.

Methods. The data from the USS were reduced and calibrated using the same methods as presented in the S-PLUS DR2. An additional step was introduced, accounting for the offset between the observed magnitudes off the USS and the predicted magnitudes from the very low-resolution Gaia XP spectra.

Results. This first release contains data for 163 observed fields totaling ~324 deg² along the Celestial Equator. The magnitudes obtained from the USS are well-calibrated, showing a difference of ~15 mmag compared to the predicted magnitudes by the GaiaXPy toolkit. By combining colors and magnitudes, 140 candidates for EMP or UMP have been identified for follow-up studies.

Conclusions. The S-PLUS USS DR1 is an important milestone in the search for bright metal-poor stars, with magnitudes in the range 10 < r ≤ 14. The USS is an ongoing survey; in the near future, it will provide many more bright metal-poor candidate stars for spectroscopic follow-up.