# A Cold Stellar Stream in Pegasus

## TL;DR

This paper reports the discovery of a faint, narrow stellar stream in Pegasus, identified through SDSS and Pan-STARRs data, likely originating from a globular cluster, and characterized by its age, metallicity, and spatial extent.

## Contribution

The paper presents the first detection and detailed characterization of a new stellar stream in Pegasus, using matched filter techniques on SDSS and Pan-STARRs data.

## Key findings

- Stream extends over 9 degrees (2.5 kpc) in Pegasus.
- Stream's width is 112 pc, indicating a globular cluster origin.
- Detected in both SDSS and Pan-STARRs data.

## Abstract

We report the serendipitous discovery of a stellar stream in the constellation Pegasus in the south Galactic hemisphere. The stellar stream was detected using the SDSS Data Release 14 by means of a matched filter in the color--magnitude diagram that is optimised for a stellar population that is 8 Gyr old with [Fe/H] = $-$0.46 dex, and located at heliocentric distance of 18 kpc. The candidate stream is faint (turnoff point at $r_0 \sim$ 19.6), sparse and barely visible in SDSS photometry. It is also detected in the (shallower) Pan-STARRs data. The residual stellar density in the $(u-g)_0$, $(g-r)_0$ color--color diagram gives the same estimate for the age and [Fe/H] of this stellar population. The stream is located at a Galactic coordinates $(l,b) = (79.4,-24.6)$ and extends over 9$^\circ$ (2.5 kpc), with a width of 112 pc. The narrow width suggests a globular cluster progenitor.