Title:

       Improving the Extragalactic Distance Scale with
       Stellar Standard Candles


Wolfgang Gieren
Universidad de Concepcion
CHILE




Abstract:

Most, if not all stellar standard candles used to set up
the local calibration of the extragalactic distance scale 
do depend, to some degree, on the environmental properties
of their host galaxies. These dependences are currently
not well calibrated und contribute in a very significant way
to the current systematic uncertainty on the Hubble constant.
We have recently started on a project (the "Araucaria Project")
which investigates the environmental dependences of several
of the most important stellar standard candles, including
Cepheids, RR Lyrae stars, red clump stars, and blue supergiants.
I will briefly discuss the strategy of the project, and review
recent progress we have made on the improvement of Cepheid
variables, red clump stars and blue supergiants as distance
indicators.