2024RNAAS...8..310S

We have examined variability of the three dipper stars-EPIC 203850058, EPIC 204638512, and EPIC 205151387-using the SpeX spectrograph on NASA's Infrared Telescope facility on two nights in 2018. We combined these data with those previously published from 2017. In EPIC 204638512, the He I line was in absorption, but blueshifted in wavelength on all 4 nights, indicating outflowing gas near the disk surface. In EPIC 203850058, no net emission is seen in 2018, but in 2017 it had an absorption core that was degraded to longer wavelengths, suggesting inflowing gas. In EPIC 205151387 the He I line went from emission in the spectrum with the least extinction by dust (highest flux state), became an inverse P Cygni profile, indicating inflowing gas as the extinction increased, and finally to pure absorption when the extinction was greatest.