Detection of Coherent Pulsation Modes in the Strongly Magnetic Of?p Star NGC 1624-2 using TESS Observation

Abstract

High-cadence Transiting Exoplanet Survey Satellite (TESS) observations are promising for studies of short-term pulsational variability in magnetic O stars, which usually have long rotation periods of the order of months or years. The Of?p star NGC 1624-2 is of special interest as it possesses the strongest magnetic field measured among O stars, together with a giant magnetosphere. We detect three significant low-frequency peaks in TESS 2 minute cadence data, probably corresponding to coherent g mode pulsations. At present, this is the only magnetic O star for which pulsational variability is detected.