Detection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 Sgr
Year: 2025
Type: article
Abstract: We report on the discovery of circular polarization modulated with a period of 1.943 ± 0.002 hr 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 (P orb) of 20.8 hr, the spin period (P spin) places this system in an extreme position of the P spin versus P orb 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 P spin/P orb 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.
Source: The Astrophysical Journal
Institutions: Universidad de Buenos Aires, National University of San Juan, Institute of Astronomy and Space Physics, Laboratório Nacional de Astrofísica, Universidade Estadual Paulista (Unesp), Brera Astronomical Observatory, National Institute for Astrophysics, Universidad Nacional Autónoma de México, Instituto Nacional de Pesquisas Espaciais, Universidade do Vale do Paraíba, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Hurlingham, University of Cape Town, University of the Free State, South African Astronomical Observatory, International Gemini Observatory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, Center for Hierarchical Manufacturing, National Science Foundation, Fundação de Amparo à Pesquisa do Estado de São Paulo, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Consejo Nacional de Investigaciones Científicas y Técnicas, Ministério da Ciência, Tecnologia e Inovação, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Agência Espacial Brasileira, Agencia Nacional de Promoción Científica y Tecnológica, Kavli Institute for Theoretical Physics, University of California, Santa Barbara
Awards: G1766751478, G2330845376, G2363592151, G256225339, G3073684694, G3337620398, G5008956391, G5130850320, G5261598906, G5273685253, G5667315657, G5738493324, G6170987879, G6552784557, Search and characterization of new magnetic cataclysmic variables, G6815844370, G7329997024, G7956716990, G8085136771, Kavli Institute for Theoretical Physics, G985207216
OpenAlex ID: W4410177610