Spectroscopy on a Shoestring: Worthwhile Science for Undergraduates

We present the results of an ongoing pilot program utilizing a commercially available SBIG Self-Guided Spectrograph (SGS) and a relatively small Celestron 14" on-campus telescope. Low resolution spectroscopy (2.4Å) is being carried out at red wavelengths (6400-7600Å). We chose this wavelength range to take advantage of the high quantum efficiency of the detector and because of the presence of important spectra features such as Hα and Titanium Oxide (TiO). We are testing the scientific viability of the spectroscopic system by initially observing a sample of Be stars as well as bright pulsating red giants,supergiants, and cepheids.

Be stars are noteworthy because they have strong and often variable Hα 6563Å emission. We have photometric observations of the Pleiades star Pleione (BU Tau), ω Ori, and X Per (HD 24534). This allows the comparison of Hα emission changes on both short time scales as well as long ones, particularly for both ω Ori and Pleione. For Pleione, dramatic night to night changes were seen in both the strength and profile of the Hα emission feature. Photometric observations of ω Ori have been carried out at Villanova since 1982 to the present. Having simultaneous spectroscopy and photometry is allowing insights into the nature of its variability.

Spectroscopy of pulsating red giants/supergiants as well as cepheids are of interest. Some representative stars include Mira, α Ori, and TV Gem, as well as the cepheids δ Ceph, Polaris, and SV Vul. These stars undergo spectral changes as they pulsate. For the M stars in particular, the TiO bands are sensitive to temperature changes in the star. Complementary V and Wing near-IR TiO band photometry is also being carried out for the cooler stars. The initial results of this study will be presented, showing worthwhile results using a small spectrograph and dedicated telescopes. We acknowledge support of this research by the NASA Delaware Space Grant College and Fellowship Program NGT5-40024.