Abstract
We determine three independent Population II distance moduli to the Fornax dwarf spheroidal (dSph) galaxy, using wide-field, ground-based VI imaging acquired with the Magellan-Baade telescope at Las Campanas Observatory. After subtracting foreground stars using Gaia EDR3 proper motions, we measure an I-band tip of the red giant branch(TRGB) magnitude of I-0(TRGB) = 16.753 +/- 0.03(stat) +/- 0.037(sys) mag, with a calibration based in the LMC TRGB giving a distance modulus of mu(TRGB)(0) = 20.80 +/- 0.037(stat) +/- 0.057(sys) mag. We determine an RR Lyrae (RRL) distance from template mean magnitudes, with periods adopted from the literature. Adopting a Gaia DR2 calibration of first overtone RRL period-luminosity and period-Wesenheit relations, we find mu(PLZ)(0) = 20.74 +/- 0.01(stat) +/- 0.12(sys) mag and it mu(PWZ)(0) = 20.68 +/- 0.02(stat) +/- 0.07(sys) mag. Finally, we determine a distance from Fornax's horizontal branch (HB) and two galactic globular cluster calibrators, giving mu(HB )(0)= 20.83 +/- 0.03(stat) +/- 0.09(sys) mag. These distances are each derived from homogeneous IMACS photometry, are anchored to independent geometric zero-points, and utilize different classes of stars. We therefore average over independent uncertainties and report the combined distance modulus = 20.770 +/- 0.042(stat) +/- 0.024(sys) mag (corresponding to a distance of 143 +/- 3 kpc).