Details of observations Our observations, from which we inferred S301, comprise 19 datasets spanning more than 8 years. We first noted S301 in 2023, when pointing directly to Sgr A*. Given the position of the star close to Sgr A* and its large proper motion, it was clear that it might be on a tight orbit,
Kouveliotou, C. et al. An X-ray pulsar with a superstrong magnetic field in the soft γ-ray repeater SGR1806 – 20. Nature 393, 235–237 (1998). Article ADS CAS Google Scholar Lai, D. & Ho, W. C. G. Polarized X-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization. Phys. Rev. Lett. 91, 071101 (2003). Article
