SiO MASERS IN ASYMMETRIC MIRAS. III. IK TAURI

Journal Article · Mon Mar 01 04:00:00 EST 2010 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/187/1/107; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301226

Cotton, W D ^[1]; Ragland, S ^[2]; Pluzhnik, E A ^[3]; Danchi, W C ^[4]; Traub, W A ^[5]; Willson, L A ^[6]

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1. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States)
2. W. M. Keck Observatory, 65-1120 Mamalahoa Hwy, Kamuela, HI 96743 (United States)
3. NASA-Ames Research Center, Moffett Field, CA 94035 (United States)
4. NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States)
5. Jet Propulsion Laboratory, California Institute of Technology, M/S 301-451, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States)
6. Department of Physics and Astronomy, Iowa State University, Ames, IA 50014 (United States)

This is the third paper in a series of multi-epoch observations at 7 mm wavelength of the SiO masers in several asymptotic giant branch stars from a sample of Mira variable stars showing evidence of asymmetric structure in the infrared. These stars have been 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 IK Tauri (IK Tau). There is a persistent elliptical distribution of the masers around the star {approx}40 x {approx}30 mas in size with a major axis at position angle {approx}30 deg. The SiO masers in the circumstellar envelope exhibit large-scale systematic motions which reverse direction on timescales of a decade, roughly the interval between the ejections of dust shells. The orientations on the sky of the apparent rotation-like bulk motion and of the major axis of the maser ellipse differ by 37 deg. (2.5{sigma}) making any relationship uncertain. The systemic velocity of IK Tau is estimated to be 33.3 {+-} 1.0 km s{sup -1}. A comparison is made with the model calculations of Gray et al. which predict some but not all observed features.

• OSTI ID: 21301226
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 187; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
DISTRIBUTION
DUSTS
MASERS
ROTATION
SILICON OXIDES
STELLAR ATMOSPHERES
TELESCOPES
VARIABLE STARS