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Three strongly magnified individual stars have been discovered in zvirgul1 galaxies thanks to temporary boosts from microlensing. All were discovered as transient events that have since faded. Now a more persistent and distant lensed star has been discovered at zvirgul6 comma named d_commaEarendeld_comma (d_commamorning lightd_comma). Its extremely high magnification has persisted for 3.5 years between HST observations comma consistent with microlensing simulations of this object. But HST monitoring of the zvirgul1 stars revealed things weren.t always as they seemed. Here we propose the first repeat monitoring of Earendel in the same WFC3-IR filter comma with 4 more epochs F110W imaging. These data will yield Earendel.s baseline flux to better constrain its magnification comma and thus luminosity and mass. Current HST data suggest it is likely very massive > 50 M_sun. And at zvirgul6 comma it is likely low metallicity < 0.2 Z_sun. Very massive low metallicity stars are extremely rare in the local group and thus hard to study locally. Such stars are the likely progenitors of virgul30 M_sun black holes measured by LIGO gravitational wave detections. But models of their evolutionary tracks are highly uncertain. Remarkably comma this isolated zvirgul6 star may offer the best opportunity to pinpoint the giant branch of a low metallicity massive star. Approved JWST GO observations will constrain the star.s temperature comma putting a zvirgul6 star on the H-R diagram with a luminosity (and mass) precision significantly improved by this HST proposal. To support the various communities interested in these results comma we waive any proprietary period to the data comma in the same spirit as the previous HST observations and approved JWST observations of this exciting target.