2008/05/12 by L. D. Matthews, Y. Libert, E. Gérard +3
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Background radiation #Cosmology #Luminosity #Stars #Stellar evolution #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/589968
accepted to ApJ; version with full-resolution figures available at: http://www.cfa.harvard.edu/~lmatthew/Mira_HI.pdf
arxiv created 2008/05/12 · openalex publication_date 2008/08/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report the detection of an H I counterpart to the extended, far-ultraviolet-emitting tail associated with the asymptotic giant branch star Mira ( o Ceti). Using the Nançay Radio Telescope (NRT), we have detected emission as far as 88' north of the star, confirming that the tail contains a significant atomic component ( M H I ~ 4 × 10 −3 M ☉ ). The NRT spectra reveal a deceleration of the tail gas caused by interaction with the local interstellar medium. We estimate an age for the tail of ~1.2 × 10 5 yr, suggesting that the mass-loss history of Mira has been more prolonged than previous observational estimates. Using the Very Large Array we have also imaged the H I tail out to ~12' (0.4 pc) from the star. The detected emission shows a "head-tail" morphology, but with complex substructure. Regions with detected H I emission correlate with far-ultraviolet-luminous regions on large scales, but the two tracers are not closely correlated on smaller scales (≲1'). We propose that detectable tails of H I are likely to be a common feature of red giants undergoing mass loss.