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N. Homeier (U of Wisconsin-Madison), R. Blum (CTIO), P. Conti (U of Colorado), A. Damineli (IAG, University of Sao Paulo)
We have begun a near infrared survey for emission-line stars in the plane of the Milky Way. The short life-span of these massive stars means that they are tracers of recent star formation in our Galaxy. As they evolve, their spectra become dominated by emission line features, partly in the Luminous Blue Variable (LBV) phase, and eventually in the Wolf-Rayet stage. The presence of emission lines (flux above the continuum level) eases the identification and classification of massive stars, which are relatively rare and thus typically at large distances from the sun and faint apparent magnitudes. With their high luminosity, massive stars could, in principle, be observed in the optical across the Galaxy were it not for the presence of interstellar dust in the Milky Way. Galactic plane surveys of distant stars at visible wavelengths are hopeless, but in the near infrared, the extinction is much lower. Our imaging program uses narrow band filters in the lines of He I, He II, Br\gamma, and C IV; these lines are present in the 2 \mum (K band) spectra of evolved, massive stars. From this narrow-band photometric data, we select candidates for follow-up spectrscopy. From survey data near the Galactic Center, we have spectroscopically confirmed our first emission-line candidate, a WR star. The spectrum clearly shows the strong lines of C IV and C III (2.08, 2.11 mum) characteristic of the WC subtype. A progress report on further detections and classifications of additional luminous emission line stars will be given.