Image Details
Caption: Figure 14.
Portions of the 2019 August HIRES spectrum highlighting the spectral similarity of LkHα 225 South (magenta) to other outbursting sources. The absorption component in LkHα 225 South bears resemblance at shorter wavelengths (e.g., top panel) to that of the FU Ori stars V1515 Cyg, V1057 Cyg, and V2493 Cyg (PTF 10qpf, HBC 722). At longer wavelengths (e.g., bottom panel) the absorption component is less obvious, but still present in the stronger lines. Note in particular the presence of Ba II, which is atypical in nonoutbursting T Tauri or Herbig Ae/Be stars, but generally is seen in FU Ori objects. In addition to the weakening absorption component toward longer wavelengths, there is increasingly weak emission, which can be appreciated by comparison with another recent outbursting source, Gaia 19ajj. Like LkHα 225 South, this source has a mixed spectrum of absorption and emission lines in neutral metals, with overall stronger emission and weaker absorption relative to LkHα 225 South.
© 2022. The Author(s). Published by the American Astronomical Society.