Thin stellar stream on a retrograde orbit at 30kpc

We discover that the stream extends over ~29{deg} on the sky (increasing the known length by 18{deg}), which is comparable to the kinematically cold Phoenix, ATLAS, and GD-1 streams. Using blue horizontal branch stars, we resolve a distance gradient along the Jet stream of 0.2kpc/deg, with distances ranging from D{sun}~27-34kpc.

We use natural splines to simultaneously fit the stream track, width, and intensity to quantitatively characterize density variations in the Jet stream, including a large gap, and identify substructure off the main track of the stream. Furthermore, we report the first measurement of the proper motion of the Jet stream and find that it is well aligned with the stream track, suggesting the stream has likely not been significantly perturbed perpendicular to the line of sight.