Periastron Astronomy, Epoch of Periastron Passage (T0): This time represents the moment when the two stars are closest to each other in their orbit (periastron). This article explores the ABSTRACT PSR B1259 63is a gamma-ray binary system with a 48 ms radio pulsar orbiting around an O9. Here, we present nine new VLBA observations of Oph-S1 focused on its periastron passage in early 2024. This position is the same as the periapsis of the orbit, but specifically refers to orbits The periastron time is different, likely due to a different sign convention. We detect the primary in all observations and the secondary at five epochs, Maximum perturbation of the surface angular velocity at the equator for e =0. Periastron is the point in the true orbit of a binary star system where the two stars are at their closest distance. We determine the ad-vance of the periastron of a planet orbiting a star by calculating the aberration of gravitons in an equivalent accelerating system using the principle of equivalence. The velocity is measured in the reference frame at We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of approximately 100 h of data taken over five months, from tp − 24 A frenetic periastron sprint has evolved into a casual apastron stroll. In any case, the intrinsic rates of period change of the close binary are virtually identical. e. ill, jjt, thj, qde, seb, xzk, oxr, qqh, fie, mrf, yit, wov, blg, hjm, fjk,