EPIC 204278916: A Tabby's Star Twin

The peculiar dipping events in the disk-bearing young-stellar object EPIC 204278916

Authors:

Scaringi et al

Abstract:

EPIC 204278916 has been serendipitously discovered from its K2 light curve which displays irregular dimmings of up to 65% for ~25 consecutive days out of 78.8 days of observations. For the remaining duration of the observations, the variability is highly periodic and attributed to stellar rotation. The star is a young, low-mass (M-type) pre-main-sequence star with clear evidence of a resolved tilted disk from ALMA observations. We examine the K2 light curve in detail and hypothesise that the irregular dimmings are caused by either a warped inner-disk edge or transiting cometary-like objects in either circular or eccentric orbits. The explanations discussed here are particularly relevant for other recently discovered young objects with similar absorption dips.