NICER observation list: Target ID 771201

XTE J1829-098 is a member of the rare group of HMXBs that exhibit very sharp periodic outbursts, and it is the only member of that group in our Galaxy. Previous TOO observations show that NuSTAR and NICER can provide high-quality data on the source. However, they did not cover a full outburst and were not obtained simultaneously. We can probe much deeper into the nature of this source by carrying out pre-planned systematic simultaneous observations, supported by ground-based IR observations. We will study the timing properties, the CRSF in the spectrum, and search for the start of the onset of the propeller regime.