Transformations between the theoretical and observational planes in the HST–NICMOS and WFPC2 photometric systems

Color–temperature relations and bolometric corrections in the HST–NICMOS F1110W, F160W and F222M and in the WFPC2 F439W, F555W and F814W photometric systems, using two different sets of model atmospheres, have been derived. This database of homogeneous, self–consistent transformations between the theoretical and observational planes also allows combinations of visual and infrared quantities, without any further transformation between the two different photometric systems. The behavior of the inferred quantities with varying the stellar parameters, the adopted model atmospheres and the instrumental configurations are investigated. Suitable relations to transform colors and bolometric corrections from HST to ground–based photometric systems are also provided. Subject headings: methods: data analysis — techniques: photometric — atlases — stars: atmospheres — stars: fundamental parameters