An overview of the observational and theoretical studies of HH 1 and 2 Posted on June 26, 2014 by UHNAI Webmaster in Raga, A.C., B. Reipurth, J. Canto, M.M. Sierra-Flores, M.V. Guzman (). An overview of the observational and theoretical studies of HH 1 and 2. , 47,