Linear Sizes from the Palomar Testbed Interferometer Giant Star Survey

The Palomar Testbed Interferometer (PTI) Giant Star Survey aims to leverage the large body of angular size data available from PTI, previously unpublished. The PTI archive has data for observations of 375 giant stars from PTI taken from 1997 to 2008. We have found a range of diameters of the stars from ~1 to 5.3 milliarcseconds from an initial sample of 64 stars. An average of ~4 stars per spectral type from G8III to M6III show a steady progression from 10 to 100 solar radii. A similar rise in radius correlates with V-K color index from +2 to +6. Outlier objects in these relationships appear to be correlated with poor luminosity classification.