SiO maser VLBA observations toward VX Sgr are performed at five epochs, and lots of maser spots are obtained. We make a statistical analysis on these spots. It is shown that the apparent sizes and the fluxes of maser spots decrease with increasing the distance from the central star. In addition, the similarity between the v = 1,2 (J = 1−0) spectrums increases with epochs, consistent with the full width at half maximum (FWHM), while the total fluxes increase. The results may be related to the changeable pumping mechanisms.

中文翻译：

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VX Sgr 周围 SiO 脉泽的观测特征

SiO 脉泽VLBA 对VX Sgr 的观测在5 个历元上进行，获得了大量的脉泽光斑。我们对这些点进行统计分析。结果表明，脉泽斑的表观尺寸和通量随着与中心恒星距离的增加而减小。此外，v = 1,2 ( J = 1−0) 光谱之间的相似性随着时期的增加而增加，与半峰全宽 (FWHM) 一致，而总通量增加。结果可能与可变的泵送机制有关。