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Aims. Our goal is to estimate the star formation main sequence (SFMS) and the star formation rate density (SFRD) at z = 0.017 (d . 75 Mpc) using the Javalambre Photometric Local Universe Survey (J-PLUS) first data release, that probes 897.4 deg2 with twelve optical bands. Methods. We extract the Ha emission flux of 805 local galaxies from the J-PLUS filter J0660, being the continuum level estimated with the other eleven J-PLUS bands, and the dust attenuation and nitrogen contamination corrected with empirical relations. Stellar masses (M), Ha luminosities (LHa), and star formation rates (SFRs) were estimated by accounting for parameters covariances. Our sample comprises 689 blue galaxies and 67 red galaxies, classified in the (u - g) vs. (g - z) color–color diagram, plus 49 AGN. Results. The SFMS is explored at log M 8 and it is clearly defined by the blue galaxies, with the red galaxies located below them. The SFMS is described as log SFR = 0.83 log M -8.44. We find a good agreement with previous estimations of the SFMS, especially those based on integral field spectroscopy. The Ha luminosity function of the AGN-free sample is well described by a Schechter function with log L * Ha = 41.34, log f * = -2.43, and a = -1.25. Our measurements provide a lower characteristic luminosity than several previous studies in the literature. Conclusions. The derived star formation rate density at d . 75 Mpc is log SFR = -2.10 ± 0.11, with red galaxies accounting for 15% of the SFRD. Our value is lower than previous estimations at similar redshift, and provides a local reference for evolutionary studies regarding the star formation history of the Universe © 2021 EDP Sciences. All rights reserved., Based on observations made with the JAST/T80 telescope for J-PLUS project at the Observatorio Astrofísico de Javalambre in Teruel, a Spanish Infraestructura Cientifico-Técnica Singular (ICTS) owned, managed and operated by the Centro de Estudios de Física del Cosmos de Aragón (CEFCA). Data has been processed and provided by CEFCA’s Unit of Processing and Archiving Data (UPAD). Funding for the J-PLUS Project has been provided by the Governments of Spain and Aragón through the Fondo de Inversiones de Teruel; the Aragón Government through the Research Groups E96, E103, and E16_17R; the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) with grants PGC2018-097585-B-C21 and PGC2018-097585-B-C22; the Spanish Ministry of Economy and Competitiveness (MINECO) under AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, and ICTS-2009-14; and European FEDER funding (FCDD10- 4E-867, FCDD13-4E-2685). The Brazilian agencies FINEP, FAPESP, and the National Observatory of Brazil have also contributed to this project. J.M.V. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV 2017-0709), and grant AYA2016-79724-C4-4P. R.A.D. acknowledges support from the Conselho Nacional de Desenvolvimento Científico e Tecnolágico –CNPq through BP grant 308105/2018-4, and the Financiadora de Estudos e Projetos – FINEP grants REF. 1217/13 – 01.13.0279.00 and REF 0859/10 – 01.10.0663.00 for hardware support for the J-PLUS project through the National Observatory of Brazil. We thank the help of Prof. G. Gavazzi in the analysis and understanding of Hα3 data. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of Astropy, a community-developed core Python package for Astron omy (Astropy Collaboration 2013), and Matplotlib, a 2D graphics package used for Python for publication-quality image generation across user interfaces and operating systems (Hunter 2007). Some of the data sets discussed in the manuscript were recovered with WebPlotDigitizer (https://automeris.io/WebPlotDigitizer/index.html), a free software developed to facilitate easy and accurate data extraction from a variety of plot types.

Our goal is to morphologically classify the sources identified in the images of the J-PLUS early data release (EDR) into compact (stars) or extended (galaxies) using a suited Bayesian classifier. J-PLUS sources exhibit two distinct populations in the r-band magnitude vs. concentration plane, corresponding to compact and extended sources. We modelled the two-population distribution with a skewed Gaussian for compact objects and a log-normal function for the extended ones. The derived model and the number density prior based on J-PLUS EDR data were used to estimate the Bayesian probability of a source to be star or galaxy. This procedure was applied pointing-by-pointing to account for varying observing conditions and sky position. Finally, we combined the morphological information from g, r, and i broad bands in order to improve the classification of low signal-to-noise sources. The derived probabilities are used to compute the pointing-by-pointing number counts of stars and galaxies. The former increases as we approach to the Milky Way disk, and the latter are similar across the probed area. The comparison with SDSS in the common regions is satisfactory up to r ~ 21, with consistent numbers of stars and galaxies, and consistent distributions in concentration and (g - i) colour spaces. We implement a morphological star/galaxy classifier based on PDF analysis, providing meaningful probabilities for J-PLUS sources to one magnitude deeper (r ~ 21) than a classical boolean classification. These probabilities are suited for the statistical study of 150k stars and 101k galaxies with 15 < r < 21 present in the 31.7 deg2 of the J-PLUS EDR. In a future version of the classifier, we will include J-PLUS colour information from twelve photometric bands., Submitted to Astronomy and Astrophysics. 14 pages, 16 figures, 1 tables. Comments are welcome. All extra figures and the number counts files will be available with the paper in press