The flux-calibrated UH 2.2 m/SNIFS and IRTF/SpeX spectra of the white dwarf primary COCONUTS-1A. Flux uncertainties are shown as the gray shadow, and prominent telluric absorption features are noted by “⊕.” Here, we convert the wavelength of the white dwarf’s SpeX spectrum from vacuum to air based on Ciddor (1996) to match the wavelength of the SNIFS spectrum, as well as the Tremblay et al. (2011) model spectrum shown in Figure 5. The white dwarf is mostly featureless except for the Hα line, suggesting COCONUTS-1A is hydrogen-dominated (DA).

(The data used to create this figure are available.)