Detection of the White Dwarf Spin of the Long-orbital Period Magnetic Cataclysmic Variable V1082 Sgr
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 per...
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| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/adc380 |
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| Summary: | 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. |
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| ISSN: | 1538-4357 |