2022A&A...657A..58N

We present the results of a detailed investigation of the poorly studied X-ray pulsar 2S 1845-024 based on data obtained at the NuSTAR observatory during the type I outburst in 2017. Neither pulse phase-averaged nor phase-resolved spectra of the source show evidence for a cyclotron absorption feature. We also used data obtained from other X-ray observatories (Swift, XMM-Newton and Chandra) to study the spectral properties as a function of orbital phase. The analysis reveals a high hydrogen column density for the source reaching ∼10²⁴ cm^–2 around periastron. Using high-quality Chandra data we were able to obtain an accurate localization of 2S 1845-024 at RA = 18:48:16.8 and Dec = -2:25:25.1 (J2000), which allowed us to use infrared (IR) data to roughly classify the optical counterpart of the source as an OB supergiant at a distance of ≥15 kpc.