Authors: Bishwas L. Shrestha (Princeton University), David J. McComas (Princeton University), Eric J. Zirnstein (Princeton University), George Livadiotis (Princeton University), Heather A. Elliott (Southwest Research Institute), Pontus C. Brandt (The Johns Hopkins University), Alan Stern, Andrew R. Poppe (University of California at Berkley), Joel Parker (Southwest Research Institute), Elena Provornikova (The Johns Hopkins University), Kelsi Singer (Southwest Research Institute), Anne Verbiscer (University of Virginia), New Horizons Heliophysics Team

This study provides a detailed analysis of fourteen distant interplanetary shocks observed by the Solar Wind Around Pluto (SWAP) instrument onboard New Horizons. These shocks were observed with a pickup ion data cadence of approximately 30 minutes, covering a heliocentric distance range of ~52-60 au. All the shocks observed within this distance range are fast-forward shocks, and the shock compression ratios vary between ~1.2 and 1.9. The shock transition scales are generally narrow, and the SW density compressions are more pronounced compared to the previous study of seven shocks by D. J. McComas et al. A majority (64%) of these shocks have upstream sonic Mach numbers greater than one. In addition, all high-resolution measurements of distant interplanetary shocks analyzed here show that the shock transition scale is independent of the shock compression ratio. However, the shock transition scale is strongly anti-correlated with the shock speed in the upstream plasma frame, meaning that faster shocks generally yield sharper transitions.