We collect all published OH, H2O, SiO and CH3OH masers in the literature. The associated infrared sources of these four masers were identified with MSX PSC catalogues. We look for common infrared properties among the sources associated with four masers and make a statistical study. The MSX sources associated with stellar OH, stellar H2O and SiO masers concentrated in a small regions and the MSX sources associated with interstellar OH, interstellar H2O and CH3OH masers also concentrated in a small regions in an [A]-[D].vs.[A][-[E] diagram. These results give us new criterion to search for coexisting stellar maser samples for OH, H2O and SiO masers and interstellar maser samples for OH, H2O and CH3OH masers.

The Sydney University Stellar Interferometer has been designed and constructed as a two aperture, single r o, long baseline, optical interferometer with wavefront-tilt compensation and dynamic optical path length compensation. Initially it will operate in the blue part of the visual spectrum but provision has been made for the addition of an additional beam-combining system for a second spectral band. The rationale behind the choice of instrumental parameters, the potential developments which have been taken into account in its construction, and the current status of SUSI are outlined.