Astron. Astrophys. 347, L35-L38 (1999)

Letter to the Editor

Preliminary results on the circumstellar envelopes of Ori and R Leo from CO 4.6 µm line emission

N. Ryde ¹, B. Gustafsson ¹, K.H. Hinkle ², K. Eriksson ¹, D.L. Lambert ³ and H. Olofsson <sup>4

1</sup> Uppsala Astronomical Observatory, Box 515, S-751 20, Uppsala, Sweden
² National Optical Astronomy Observatories ^*, P.O. Box 26732, Tucson, AZ 85726, USA
³ Department of Astronomy, University of Texas, Austin, TX 78712, USA
⁴ Stockholm Observatory, S-133 36 Saltsjöbaden, Sweden

Received 7 May 1999 / Accepted 15 June 1999

Abstract

CO 4.6 µm vibration-rotational lines are detected in fluorescent emission from the inner regions of the Betelgeuse ( Orionis) and R Leonis stellar winds. The spatially and spectrally resolved 1-0 R(1), R(2), and R(3) line profiles are found to be highly useful probes of circumstellar shells. The current data sample only a few regions of the circumstellar shells of the program stars. However, now it should be possible to obtain envelope maps and absolute flux estimates, allowing new independent estimates of mass loss rates. This will open up new possibilities in the study of the structure and dynamics of stellar winds around red giants. The temperature 4" away from Ori is found to be . For R Leo the temperature 4" North is derived to be and 4" South .

Key words: stars: AGB and post-AGB stars: circumstellar matter stars: individual: ff Ori stars: individual: R Leo stars: late-type infrared: stars

* Operated by the Association of Universities for Research in Astronomy, Inc. under cooperative agreement with the National Science Foundation

Send offprint requests to: N. Ryde (nils.ryde@astro.uu.se)

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and reductions
• 3. Analysis and results
• 4. Discussion and conclusion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: June 6, 1999
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