The Structure of the Inner Circumstellar Shell in Miras
- Author(s)
- Kenneth H. Hinkle, Thomas Lebzelter
- Abstract
We have measured CO line profiles in a time series of 42 high-resolution 1.6 - 2.5 μm spectra of R Cas. The low-excitation CO first overtone lines have a contribution from a ~1000 K region. We show that this region undergoes a periodic changes on time scales many times longer than the photospheric pulsation. Comparison with interferometry and models suggests that the ~1000 K region is at ~2R* and cospatial with the region of SiO masers and grain condensation. The CO lines are entirely in absorption requiring formation in a layer thin compared to the stellar diameter. The CO excitation temperature has been measured as low as 600 K suggesting that grains with a variety of compositions condense at ~2R*.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- National Optical Astronomy Observatory, Tucson
- Journal
- Proceedings of the International Astronomical Union
- Volume
- 14
- Pages
- 419-420
- No. of pages
- 2
- ISSN
- 1743-9213
- DOI
- https://doi.org/10.1017/S1743921318005008
- Publication date
- 08-2018
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health, Astronomy and Astrophysics, Nutrition and Dietetics, Medicine (miscellaneous), Space and Planetary Science
- Portal url
- https://ucris.univie.ac.at/portal/en/publications/the-structure-of-the-inner-circumstellar-shell-in-miras(26ddb47b-25c8-4600-a0ce-5356f06890f3).html