Confirming the Magnetic Field Detection at the Surface of χ Cyg

Abstract

We present spectropolarimetric observations of χ Cygni obtained with Neo-Narval at Télescope Bernard Lyot in 2025. We obtained observations across three epochs (2025 July, August, and October) near maximum light to search for magnetic field signatures at the stellar photosphere. We detected a clear circular polarization signal in the 2025 August observations (pulsation phases 0.99–0.01). We measure a mean longitudinal magnetic field of B l  = 3.4 ± 0.6 G. No detections were obtained for the 2025 July and October epochs. The pulsation-phase dependence suggests that field detection is tied to specific shock conditions near maximum light.