Vaccari, MattiaLiu, DeziDeng, Wenqiang2021-02-102021-02-102020Vaccari, M. et al. (2020). Variability and transient search in the SUDARE–VOICE field: A new method to extract the light curves. Monthly Notices of the Royal Astronomical Society, 493(3), 3825–38371365-2966https://doi.org/10.1093/mnras/staa558http://hdl.handle.net/10566/5885The VLT Survey Telescope (VST) Optical Imaging of the CDFS and ES1 Fields Survey, in synergy with the SUDARE survey, is a deep optical ugri imaging of the CDFS and ES1 fields using the VST. The observations for the CDFS field comprise about 4.38 deg2 down to r ∼ 26 mag. The total on-sky time spans over 4 yr in this field, distributed over four adjacent subfields. In this paper, we use the multiepoch r-band imaging data to measure the variability of the detected objects and search for transients. We perform careful astrometric and photometric calibrations and point spread function modelling. A new method, referring to as differential running-average photometry, is proposed to measure the light curves of the detected objects. With the method, the difference of PSFs between different epochs can be reduced, and the background fluctuations are also suppressed.enMethods: data analysisObservational – techniquesImage processing – techniquesPhotometric – catalogues – surveyArticle