A wealth of observations have long suggested that the vast majority of
isolated classical dwarf galaxies (Mββ=107-109 Mββ) are currently
star-forming. However, recent observations of the large abundance of
"Ultra-Diffuse Galaxies" beyond the reach of previous large spectroscopic
surveys suggest that our understanding of the dwarf galaxy population may be
incomplete. Here we report the serendipitous discovery of an isolated quiescent
dwarf galaxy in the nearby Universe, which was imaged as part of the PEARLS GTO
program. Remarkably, individual red-giant branch stars are visible in this
near-IR imaging, suggesting a distance of 31 Mpc, and a wealth of archival
photometry point to an sSFR of 2Γ10β12 yrβ1. Spectra obtained
with the Lowell Discovery Telescope find a recessional velocity consistent with
the Hubble Flow and >1500 km/s separated from the nearest massive galaxy in
SDSS, suggesting that this galaxy was either quenched from internal mechanisms
or had a very high-velocity interaction with a nearby massive galaxy in the
past. This analysis highlights the possibility that many nearby quiescent dwarf
galaxies are waiting to be discovered and that JWST has the potential to
identify them.Comment: Submitted to ApJ Letters. Comments welcome