JWST/MIRI Detection of [Ne V], [Ne VI], and [O IV] Wind Emission in the O9 V Star 10 Lacertae
Kumari, Nimisha; Gordon, Karl D.; Law, David R.; Smith, Linda J.; Leitherer, Claus; Hawcroft, Calum; Fullerton, Alexander W.; Evans, Christopher J.
United States
Abstract
We report the detection of broad, flat-topped emission in the fine-structure lines of [Ne V], [Ne VI], and [O IV] in mid-infrared spectra of the O9 V star 10 Lacertae obtained with James Webb Space Telescope/Mid-Infrared Instrument. Optically thin emission in these high ions traces a hot, low-density component of the wind. The observed line fluxes imply a mass-loss rate of >3 × 10‑8 M⊙ yr‑1, which is 1 order of magnitude larger than previous estimates based on UV and optical diagnostics. The presence of this hot component reconciles measured values of the mass-loss rate with theoretical predictions and appears to solve the "weak wind" problem for the particular case of 10 Lac.