86 GHz SiO masers toward Mira

We observed the v = 1, J = 2 --> 1, 86 GHz SiO maser transition from Mira ( o Ceti) near stellar pulsation phase phi = 0.3 with the Coordinated Millime ter VLBI Array. Maser emission was detected on two of the baselines, and ge neral size and brightness parameters were extracted. For this epoch (1998.2 6), we find that the maser features extend over roughly 1.5 to 2 stellar ra dii R-* in the north-south direction. The limited image fidelity was insuff icient to assess whether a ringlike morphology typical of other evolved sta rs with SiO masers appears in Mira also. The brightness temperatures (less than or equal to 10(10.5) K) and spot sizes (greater than or equal to 0." 0 01) generally resemble those of other maser sources measured by VLBI at 86 GHz, such as VX Sgr and R Gas. We find no coherent velocity structure sugge sted by the 86 GHz SiO masers toward Mira.