Paper Abstracts on photometry

Buser R. (1978, A&A 62, 411)


In the context of a systematic investigation of multicolor photometric systems, the UBV, RGU and uvby systems have been evaluated. Detailed spectral energy distributions for stars of various spectral types and luminosity classes have been used along with the response functions of the systems, to compute synthetic colors. A standard law of interstellar extinction has been applied to obtain the reddening parameters for the UBV and RGU systems.

The response function of the U-passband of the UBV system has been revised in order to reduce the non-linearities existing in the transformation of the synthetic U-B colors to the mean observational system. For the broad-band systems, the results are in good agreement with observations. For the uvby system the agreement is less good, indicating that higher resolution of the energy distributions will be necessary to synthesize the colors for this sytem.

Smith G.H. (1986, PASP 98, 231)


Washington CMT1T2 photometry has been obtained for a sample of field red giants for which DDO colors are also available from the literature. Washington line-blanketing indices D(M-T1) and D(C-M) have been derived, and are found to correlate very well, suggesting that they are both useful indicators of overall metal abundance [A/H]. Both parameters also correlate quite well with the DDO metallicity index dcm. Any [N/A] or [C/A] abundance variations which may exist among the present sample of old disk giants do not appear to significantly affect the D(C-m) index.
Last update: 7 Novembre 1995