Science with Brazilian robotic telescope: search for cataclysmic variables

• Grant number: 25/01204-6
• Support Opportunities: Research Grants - Visiting Researcher Grant - Brazil
• Start date: May 01, 2025
• End date: July 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Claudia Lucia Mendes de Oliveira
• Grantee: Claudia Lucia Mendes de Oliveira
• Visiting researcher: Raimundo Lopes de Oliveira Filho
• Visiting researcher institution: Universidade Federal de Sergipe (UFS). Centro de Ciências Exatas e Tecnologia (CCET), Brazil
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/26492-3 - Science with the Brazilian robotic telescope, AP.ESP

Abstract

The S-PLUS 12-band photometry offers a unique opportunity to uncover Cataclysmic Variables (CVs) in the Southern celestial hemisphere. These systems, in which a white dwarf captures matter from a companion main-sequence star, are key pieces in the study of stellar structure and evolution. While most of these systems have been identified through variability detection in the optical and/or due to their hard X-ray emission, S-PLUS enables discovery based on the spectral energy distribution in the optical range. This is not just an alternative approach, but the opening of a horizon that allows for identifying interacting binaries that were invisible to traditional surveys, such as those systems with little variability or long-term variability, and those undetectable in X-rays. Population studies indicate that the low number of known objects in certain subclasses is due to observational biases and that the so-called exotic systems are the majority. The importance of progress in this population aspect goes beyond mere numerology and addresses major open questions, for which obtaining answers necessarily involves characterizing these so-called exotic systems and exploring property correlations between them. For example, there is the question of the origin and evolution of magnetic fields in white dwarfs, the dynamics of white dwarf rotation evolution and orbital periods in these systems, aspects of matter exchange between stars related to plasma physics, and connections to the evolutionary channel that leads to Type Ia supernovae - an important link between Stellar Astrophysics and cosmological aspects related to distance measurement. The potential of S-PLUS to reveal CVs has been demonstrated in previous work of our group, with the development of methodology based on colors and spectral energy distribution of these systems. The goal here is to systematically apply the developed methodology and thus identify new CVs from the data set provided by S-PLUS. The novelty of the sample has immediate consequences for the characterization of the systems, which will also rely on two additional resources available to the Brazilian astronomical community: the telescopes at the Gemini and Pico dos Dias observatories - where projects are being carried out in alignment with the proposed work. Ultimately, the aim is to occupy a prominent position in the field by revealing and characterizing CVs, while maximizing the scientific return of the S-PLUS project and equipment funded by Brazil. (AU)