Upper panel: spectrum of Delorme 1 (AB)b as shown in Fig. 2. Bottom left: full averaged (over 12 cubes) MUSE IFS spectrum of the two components of the central binary pair, Delorme 1 AB, indicating nearly identical spectral types (∼M5 − M6). Bottom right: secondary component (B) shifted down in flux by 10⁻¹⁴ for clarity. Prominent features include very strong Hα and Na I doublet, and weaker Hβ lines in both components. The primary component (A) shows signs of Ca IRT emission, with the first two Ca II lines visible at 8498/8542 Å. This is likely associated with the recent flare because it is not detectable in B. We also note the lack of any He I features in the 6678−7281 Å range, in contrast to the companion spectrum. We detect a blueshift of ∼ − 15 km s⁻¹ in the Hα line of Delorme 1 A during the flare event, which is not detected in B. We detect no significant blue- or redshift in the lines of Delorme 1 (AB)b.