Discovery of a new phase-transient cyclotron line in A0535+26: Constraints on the accretion geometry

Ashwin Devaraj, Biswajit Paul, Varun Bhalerao +1

In November 2020, A0535+26 underwent one of its brightest outbursts, reaching nearly 12 Crab in X-ray flux. Observed by \textit{Insight-HXMT}, \textit{NuSTAR}, \textit{NICER}, and…