2023ApJ...958...99B

Hubble Space Telescope (HST) images obtained in 2018 are combined with archival HST data taken in 1995 to detect changes and measure proper motions in the HH 80/81 shock complex, which is powered by the fastest known jet driven by a forming star, the massive object IRAS 18162-2048. Some persistent features close to the radio jet axis have proper motions of >1000 km s^–1 away from IRAS 18162-2048. About 3-5 pc downstream from the IRAS source and beyond HH 80/81, Hα emission traces the rim of a parsec-scale bubble blown by the jet. Lower speed motions are seen in [S II] away from the jet axis; these features have a large component of motion at right angles to the jet. We identify new HH objects and H₂ shocks in the counterflow opposite HH 80/81. The northeastern counterflow to HH 80/81 exhibits an extended but faint complex of 2.12 μm H₂ shocks. The inner portion of the outflow is traced by dim 1.64 μm [Fe II] emission. The full extent of this outflow is at least 1500″ (∼10 pc in projection at a distance of 1.4 kpc). We speculate about the conditions responsible for the production of the ultrafast jet and the absence of prominent large-scale molecular outflow lobes.