Other major research projects carried out by Haro included the list of 8746 blue stars in the direction of the north galactic pole published jointly with W. J. Luyten in 1961. Work made with the 48-inch Palomar Schmidt using the three-color image technique developed at Tonantzintla. At least 50 of these objects turned out to be quasars (which had not yet been discovered in 1961). Haro's list of 44 blue galaxies, compiled in 1956, was a precursor to the work of Benjamin Markarian and others in searching for such galaxies. Haro also discovered a number of T Tauri stars, one supernova, more than 10 novae, and one comet.