Progress towards a universal family of UV-IR extinction laws

Abstract: We present our progress on the study of extinction laws along three diferent lines. [a] We compare how well different families of extinction laws fit existing photometric data for Galactic sightlines and we find that the Ma\'iz Apell\'aniz et al. (2014) family provides better results than those of Cardelli et al. (1989) or Fitzpatrick (1999). [b] We describe the HST/STIS spectrophotometry in the 1700-10 200 Angstrom range that we are obtaining for several tens of sightlines in 30 Doradus with the purpose of deriving an improved wavelength-detailed family of extinction laws. [c] We present the study we are conducting on the behavior of the extinction law in the infrared by combining 2MASS and WISE photometry with Spitzer and ISO spectrophotometry.