The Structure of the Inner Circumstellar Shell in Miras

Autor(en)
Kenneth H. Hinkle, Thomas Lebzelter
Abstrakt

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(en)
Institut für Astrophysik
Externe Organisation(en)
National Optical Astronomy Observatory, Tucson
Journal
Proceedings of the International Astronomical Union
Band
14
Seiten
419-420
Anzahl der Seiten
2
ISSN
1743-9213
DOI
https://doi.org/10.1017/S1743921318005008
Publikationsdatum
08-2018
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Schlagwörter
ASJC Scopus Sachgebiete
Public Health, Environmental and Occupational Health, Astronomy and Astrophysics, Nutrition and Dietetics, Medicine (miscellaneous), Space and Planetary Science
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/the-structure-of-the-inner-circumstellar-shell-in-miras(26ddb47b-25c8-4600-a0ce-5356f06890f3).html