'Hard' X-ray emission from dwarf novae

We report the results of a sensitive search for ‘hard’ $$(\gtrsim 2 \enspace\text {keV})$$ X-ray emission from 47 dwarf novae, based on Ariel V Sky Survey Instrument (SSI) observations, using the Point Summation Technique (PST). X-ray emission is detected from the region of two dwarf novae: SS Cygni and EX Hydrae. The refined SSI error box for the previously catalogued source, 2A 1251-290, is consistent with the position of EX Hya, and the variability indicated by the X-ray light curve implies that the cluster originally suggested is no longer a reasonable identification. These results are discussed in terms of the model described by Fabian et al. for X-ray emission from a system containing an accreting white dwarf.