2022RNAAS...6..179R

Infrared spectroscopy of the recurrent nova U Scorpii from 14.2 days after its 2010 outburst reveals two very strong infrared coronal lines: [Si X] at 1.4305 μm and [Al IX] at 2.0400 μm. Taken together with the detection of coronal lines in the 2022 outburst, this suggests that coronal line emission from U Sco may be a regular, if previously under-observed, occurrence. The strength of the two coronal lines relative the H I emission, and the surprising absence of several commonly seen coronal lines, including some that form under similar conditions as the [Si X] and [Al IX] features, are discussed.