A Circumstellar H2O Maser Associated With the Galactic Circumnuclear Molecular Disk?

In the course of conducting a survey of 22-GHzH2O masers in the inner galaxy, we discovered a maser source in Sgr A West. It is located ~30'N and 35'E of Sgr A*, near the edge of the Eastern arm of the radio mini-spiral, which presumably coincides with the inside edge of the circumnuclear disk. Furthermore, the radial velocity of the maser is remarkably similar to that expected for gas in the circumnuclear disk at this location. We have also found a luminous, reddened star having a bolometric magnitude and IR spectrum characteristic of an M supergiant at this location. The extinction is consistent with a location in the inner galaxy, near or possibly within the circumnuclear disk. If this star is associated with the circumnuclear disk, it will have implications for star formation in the unusual galactic center environment.