Likely Metal Scarring in the Magnetic White Dwarf LHS 2534

Abstract There are only three white dwarfs known to possess metal-enriched polar caps due to magnetically guided accretion. These rare systems offer a unique opportunity to study planetesimal accretion and how magnetic fields influence the spreading of material across the atmosphere. To better study these processes however, more targets are needed. Here we report our findings from an observing campaign on the magnetic white dwarf LHS 2534. Time-resolved spectra at the MMT show clear variability in the strength of the Na i and Cr i features. We find that the strengths of these features vary over a period of 19.46 and 19.36 hr respectively, closely matching the 20.22 hr period determined from K2 photometry. Our findings demonstrate the ability to detect and study these variable objects with spectroscopy, and time-series observations of similar targets in the future will provide more insight into how these atmospheres form.