Searching for Superhump-like variations on Cata- clysmic Variables using VVV and VVVx data Lagos, Denisse1 & Barría, Daniela. Bachelor’s Degree in Astronomy, Universidad Central, Coquimbo, Chile 1denisse.lagos@alumnos.ucentral.cl Abstract At this work, we explore the presence of Superhumps(SHs) and SHs-like variations at infrared (IR) wavelengths in cataclysmic variable stars (CVs), specifically in Dwarf Nova and Classical Nova types. SHs – periodic photometric oscillations that are slightly shifted from the orbital period (Po) – are usually seen during superoutbursts and are linked to instabilities in close binary systems’s accretion disks. Previous studies have mainly studied SHs in optical bands, so this study focuses on detecting them in the IR. Using light curves from the VVV/x project and the VIVA catalogue, 140 CV systems were identified, and 85 of them were analyzed so far, for frequency detection via periodogram analysis using Period04. Although significant frequencies were detected in the periodograms, none of them corresponds strictly with a SH period. However, at some systems, we have found SHs-like variations. Further studies using the PDM technique will be conducted in the near future. Introduction CVs are a type of close binary systems, where a white dwarf (WD-primary star) pulls ma- terial from a main-sequence companion (sec- ondary star) through an accretion disk (Fig.1 and Fig.2). This, driven by viscosity, loss orbital energy as gas spirals toward the WD, emitting radiation that contributes to the total luminos- ity of the system (Warner, 1995). Light curves reveal changes in a star’s brightness over time and for binary systems they often show dips due to the orbital motion. Additional photometric variabilities, known as superhumps (SHs), might appear in the light curves of CVs as a result of instabilities in the accretion disk (Bruch, et al. 2022, 2023). SHs come in two types: positive SHs, with a period slightly longer than the Po, and negative SHs, with a slightly shorter period. We used 85 CV light curves retrieved from the VVV Survey (Minniti et al. 2009) database at band Ks, to perform a time series analysis us- ing Period04a.To our knowledge, SHs have not been investigated in the IR and this is the main motivation of this work. awww.period04.net Data Analysis We used the VIVA catalogue (Ferreira Lopes et al. 2020) to select 140 CVs (Dwarf Nova and Nova systems) which have been previously studied at visible wavelengths. Ks band light curves for these targets, were downloaded from the VSA-VISTA Science Archivea. A time series analysis was carried out using the software Pe- riod04 in order to identify significant frequencies via periodograms. ahttp://vsa.roe.ac.uk/ Figures Fig.1: An schematic view of a CV system. Fig.2: An accretion disk illustration. Results System ID515472646464 The VVV/DR5 Ks light curve of this CV shows magni- tude fluctuations between 13.5 and 14.1, reflecting typi- cal brightness variations for such systems (see right up- per panel). In the periodogram (bottom panel), a signif- icant peak appears at a frequency of ∼7.1 d−1, with a SNR exceeding 4σ. This periodicity corresponds to the Po according to previous analysis (Ferreira Lopes et al. 2020). The table (right lower panel) list the significant frequencies, amplitudes and SNR found in Period04. System ID515600867128 This CV displays a Ks light curve with magnitude variations between 10.0 and 12.5, reflecting brightness changes typical for these systems. In the periodogram, a significant peak appears at a frequency of ∼1 d−1, with a SNR exceeding 4σ. This finding is slightly higher than the Po reported in the VIVA catalogue and thus we consider that this frequency corresponds to a SH-like variation. System ID515845503587 In this system, the light curve shows magnitude vari- ability between 11.5 and 14.5, reflecting the system’s in- trinsic orbital motion. The periodogram displays a sig- nificant peak at a frequency near 0.0015 d−1