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Session 108 - The Galactic Stellar Disk & Halo.
Display session, Saturday, January 10
Exhibit Hall,
We are investigating the faint end of the stellar luminosity function by identifying red point-sources in the images of a CCD transit survey done at the 5 meter telescope at Palomar. Here we present preliminary results based on photometric data for a portion of the survey. The survey consists of long, narrow images covering 42 square degrees at a range of galactic latitudes in both galactic hemispheres down to R\sim 23. Approximately 50,000 M dwarfs will be examined, and our goal is to produce an accurate measurement of the stellar luminosity function for 8 < M _V < 20. The survey data were taken with the CCDs clocked in continuous read mode, and use two non-standard filters centered at 7200 and 9750 Angstroms. The 9750 Åfilter utilizes the longest wavelength sensitivity of a CCD, and will allow us to discover very red objects. As a result of the search, we expect to uncover several new Ultra-Cool M dwarfs. In October 1997, we used the 0.9 meter telescope at KPNO to obtain standard VRI photometry of a subset of the stars in this survey. We have computed transformations from the Palomar system to Johnson V and Kron-Cousins R and I, as well as confirmed the ability of the transit observations to do accurate photometry over an 8 hour range of Right Ascension. Our total survey includes three strips, of which one has been fully processed. We present the photometric results from this strip, and preliminary limits on the faint end of the stellar luminosity function. In the near future, we will perform classification spectroscopy of 150-200 of these M dwarfs with the Hobby-Eberly Telescope at McDonald Observatory.
The author(s) of this abstract have provided an email address for comments about the abstract: harlow@astro.psu.edu
