Description
We present the results of simultaneous time monitoring observations of SiO J=2-1 and J=3-2 maser emission for 10 late-type stars (8 Mira variables, 1 OH/IR star, and 1 supergiant) with the 14m radio telescope at Taeduk Radio Astronomy Observatory from 1999 January to 2001 February. The SiO v=1, J=2-1 and J=3-2 maser emission was detected at almost all observational epochs. The SiO v=2, J=2-1 maser was detected from 4 late-type stars (VY CMa, R Cas, Cyg, R Leo) and the v=2, J=3-2 maser was detected from 7 stars (R Aqr, TX Cam, R Cas, Cyg, W Hya, R Leo, IK Tau). The v=3, J=2-1 and masers were also detected from Cyg and TX Cam, respectively. Based on these observational data, line profile and peak velocity variations with respect to stellar velocity, antenna temperatures, and their ratio variations as a function of optical phase of central star were investigated. Description:
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