Detection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 Sgr

Lima, Isabel de JesusTovmassian, GagikRodrigues, Claudia VilegaOliveira, Alexandre Soares deLuna, Gerardo Juan ManuelBuckley, David A. H.Silva, Karleyne Medeiros Gomes daFigueiredo, Ana Carolina MattiuciSouza, Diego Carvalho deSchlindwein, WagnerMarques, Fernando FalkenbergPalhares, Matheus Soares2025-08-142025-08-14https://repositorio.univap.br/handle/123456789/1019We report on the discovery of circular polarization modulated with a period of 1.943 ± 0.002hr in the cataclysmic variable V1082 Sgr. These findings unambiguously reveal the rotation of a magnetic white dwarf and establish its intermediate polar nature. Along with its extraordinary long orbital period (Porb) of 20.8 hr, the spin period (Pspin) places this system in an extreme position of the Pspin versus Porb distribution. The circular polarization phase diagram has a single peak and an amplitude smaller than 1%. These data were used to model the postshock region of the accretion flow on the white dwarf surface using the CYCLOPS code. We obtained a magnetic field in the white dwarf pole of 11 MG and a magnetospheric radius consistent with the coupling region at around 2–3 white dwarf radii. The Pspin/Porb value and the estimated magnetic field momentum suggest that V1082 Sgr could be out of spin equilibrium or in a spin-up state, possibly in a stream accretion mode.PDFen-USDetection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 SgrArtigos de PeriódicosThe Astrophysical Journal10.3847/1538-4357/adc380Close binary starsCataclysmic variable starsStarlight polarizationLIMA, I. J. et al. Detection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 Sgr. The Astrophysical Journal, v. 984, n. 2, p. 1-9, 2025. Disponível em: 10.3847/1538-4357/adc380.Universidade do Vale do ParaíbaUniversidade Estadual Paulista “Júlio de Mesquita FilhoInstituto de Astronomía y Física del EspacioUniversidad Nacional de San JuanLaboratório Nacional de AstrofísicaUniversidad Nacional Autonoma de MexicoOsservatorio Astronomico di BreraInstituto Nacional de Pesquisas EspaciaisUniversidad Nacional de HurlinghamSouth African Astronomical ObservatoryUniversity of the Free StateUniversity of Cape TownGemini Observatory