LBA observations for project V565 semester 2022APRS

Massive stars found in binary systems display powerful stellar winds that can collide, producing strong shocks. This leads the sources to be classified as Colliding Wind Binaries (CWBs). These shocks can accelerate particles up to relativistic energies, producing non-thermal emission from radio to high energies. We recently discovered Apep as the most extreme and luminous CWB in our Galaxy. Its non-thermal radio emission is over one order of magnitude brighter than any other CWB. A previous LBA observation resolved the radio-emitting region into a bow-shape structure characteristic of a wind-collision region. This allowed us to characterize the system, pinpoint the positions of the two stars, and measure the stellar wind momentum rate ratios. However, many open questions remain about this system and to explain its unparalleled luminosity. This new epoch would allow us to constrain the orbit of the system, and clarify if indeed one of the two WR stars exhibit a highly anisotropic stellar wind. This would represent the first case of such system, although largely speculated to explain the formation of compact binary systems that end up as short gamma-ray bursts.