2025/08/29 by Ederoclite, A., Ramió, H. Vázquez, Alvarez-Candal, A. +37
#Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2509.00214
Aims. The analysis of variability of astronomical sources is of extraordinary interest, as it allows the study of astrophysical phenomena in real time. This paper presents the Javalambre Variability Survey (J-VAR) which leverages the narrow band filters available at the Javalambre Auxiliary Survey Telescope (JAST80) at the Observatorio Astrofísico de Javalambre (OAJ). Methods. The JAST80 equipped with T80Cam, providing a field of view of 2 square degrees and a pixel scale of 0.55 arcsec/pixel has been designed for wide-field studies. The main characteristic is the availability of a variety of narrow band filters strategically located on stellar spectral features (the J0395 in correspondence of the Ca H+K doublet, the J0515 of the Mg b triplet, the J0660 of the Hα line, and the J0861 of the Ca~triplet). This project combines, for the first time, the wide-field with a variety of narrow band filters for a unique variability survey, observing each field 11~times with a standardised observing sequence. The median limiting magnitude for individual exposures are 19.1 mag in J0395 and J0515, 19.6 mag in J0660 and J0861, 19.8 mag in i, and 20.2 in g and r. The typical FWHM of the r-band images is 1.5 arcsec. Results. This article introduces the first data release of J-VAR including more than 6000 individual asteroids, 10 detected optical transients (4 discovered supernovae), and 1.3 million light curves of point-sources. On average, J-VAR delivers an unprecedented ∼5000 light curves per square degree of 11 epochs in 7 bands, opening research opportunities for theoretical studies and new discoveries alike.