1989/05/01 by T. R. Geballe, Keith Noll, D. C. B. Whittet +1 · 3 citations
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies #Astronomy and Astrophysical Research
paper · doi:10.1086/185431
openalex publication_date 1989/05/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Moderate resolution spectra from 1.05 to 3.65 microns of the post-AGN star HR 4049 show a number of features indicative of intense mass loss and unusual circumstellar chemistry. These are deep Brackett series absorption lines to rather high n states, emission in the 3.29 and 3.40 microns 'dust' features, and the rarely occurring emission features near 3.5 microns. HR 4049 is only the third star in which the 3.5micron features have been reported; the other two stars are premain-sequence objects. The physical and chemical conditions for the production of the (unknown) molecule responsible for this emission appear to be highly constrained.