Fig. 1: Active region observed by the NSF’s Daniel K. Inouye Solar Telescope (DKIST¹⁸) on 23 February 2022.

a Solar photosphere shown by a Visible-Spectro-Polarimeter (ViSP¹⁹) intensity map at 396.5 nm and an inset Visible-Broadband Imager (VBI²⁰) blue continuum image at 450.3 nm. The spectrograph slit of the ViSP scanned over the active region in the +X-direction to produce this map. The two horizontal black lines in the ViSP map are images of fiducials at the slit used for alignment purposes. The black arrow points towards the solar disc center. b Upper photosphere and lower chromosphere shown by a ViSP intensity map in the Ca II H line wing at −0.05 nm from the line core, in which the line has a line wing emission. In general, Ellerman bombs are bright in this wavelength. Within the yellow square, two Ellerman bombs were observed. The red cross points to the location of the Ellerman bomb and the place where the Stokes profiles shown in Figs. 3 and 4 were measured. The other is the bright feature at (X, Y) = (−22 arcsec, −5 arcsec). In this study, we present results for the former one. The blue and yellow squares mark the region enlarged in Fig. 2. c Chromosphere within the square is shown at the line core of Ca II H.