SIO MASERS IN ASYMMETRIC MIRAS. I. R LEONIS

Journal Article · Sat Oct 10 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/704/1/170· OSTI ID:21367466

Cotton, W D ^[1]; Ragland, S; Pluzhnik, E ^[2]; Danchi, W C ^[3]; Traub, W A ^[4]; Willson, L A ^[5]

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1. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States)
2. California Association for Research in Astronomy, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States)
3. NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States)
4. Jet Propulsion Laboratory, California Institute of Technology, M/S 301-451, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)
5. Department of Physics and Astronomy, Iowa State University, Ames, IA 50014 (United States)

This is the first paper in a series of multi-epoch observations of the SiO masers at 7 mm wavelength in several asymptotic giant branch (AGB) stars. This is a sample of Mira variable stars showing evidence of asymmetric structure in the infrared which were observed interferometrically in the infrared by Infrared Optical Telescope Array and with Very Long Baseline Array measurements of the SiO masers. In this paper, we present the observations of R Leonis (R Leo). During the period of observations, this star shows extended emission with large-scale coherent patterns in the radial velocity, possibly the result of ejecting a substantial amount of material, largely to the west. This is interpreted as an event in which material is expelled in a collimated flow, possibly following an energetic event. If common, these events may help explain the asymmetric nature of the planetary nebulae that develop from AGB stars. The systemic velocity of R Leo is estimated to be +1.0 +-0.3 km s{sup -1}. All observed radial velocities are well below the escape velocity.

• OSTI ID: 21367466
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 704; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AMPLIFIERS
ASYMMETRY
ASYMPTOTIC SOLUTIONS
ATMOSPHERES
CHALCOGENIDES
ELECTRONIC EQUIPMENT
EMISSION
EQUIPMENT
MASERS
MATHEMATICAL SOLUTIONS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NEBULAE
OXIDES
OXYGEN COMPOUNDS
PLANETARY NEBULAE
RADIAL VELOCITY
SILICON COMPOUNDS
SILICON OXIDES
STARS
STELLAR ATMOSPHERES
TELESCOPES
VARIABLE STARS
VELOCITY
WAVELENGTHS