Abstract We present Hubble Space Telescope (HST) imaging of Pegasus V and Pisces VII, along with a re-analysis of the archival imaging of Pegasus W, and Karl Jansky Very Large Array (VLA) neutral gas (H i ) observations of all three. These three ultra-faint dwarfs (UFDs) are all within the Local Group in the approximate direction of M31. The VLA observations place stringent upper limits on their H i content, with all having M HI < 10 4 M ⊙ . As the red giant branches of these UFDs are sparsely populated, we determined distances from the HST photometry of horizontal branch (HB) stars in comparison to a fiducial HB population (from M92), with all three falling in the range 0.7–1 Mpc. Using a new Python -based star formation history (SFH) fitting code (based on StarFISH ), we derive SFHs of all three UFDs. As found previously, the best-fit SFH for Pegasus W includes significant star formation well beyond the end of reionization, while the SFHs calculated for Pegasus V and Pisces VII are consistent with them having quenched over 10 Gyr ago. These findings for the latter two objects indicate that, like those in the vicinity of the Milky Way, lower-mass UFDs in the vicinity of M31 likely quenched at early times.
Jones et al. (2026) studied this question.