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Multiline Study with VLBI of SiO Masers in Evolved Stars

Published online by Cambridge University Press:  13 May 2016

Francisco Colomer*
Affiliation:
Observatorio Astronómico Nacional, Apartado 1143, E-28800 Alcalá de Henares, Spain. (Email: [email protected])

Abstract

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We present preliminary results of our observations of the 7 mm (v=1 and v=2 J=1-0) and 3 mm (v=1 J=2-1) SiO masers in the circumstellar envelopes of evolved stars. The 7mm masers were observed with the Very Large Baseline Array (VLBA) and the European VLBI Network (EVN), and the 3mm ones with the Coordinated Millimeter VLBI Array (CMVA). We find similarities between the maps, despite the non-coincidence in the location of most spots in the different 7 mm lines. The visibilities found for most compact spots are compatible with maser sources as small as 0.13 mas (or 0.023 AU at the distance of R Cas).

Type
Stars and Stellar Atmospheres
Copyright
Copyright © Astronomical Society of the Pacific 2001 

References

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