Observations of jets from low-luminosity stars. II - SVS 12, HH 30, near HL Tauri, and HH 34

Spatially resolved spectral scans were obtained for four Herbig-Haro jets emanating from low-luminosity premain-sequence stars. There appears to be a general tendency for the excitation and electron density to diminish along these jets. For three jets, the electron density dependence is close to 1/r. HH 30's scattered stellar continuum showed much weaker Fe II lines in 1985 than in 1979, indicative of variable stellar activity. The most distant knot in HH 34's jet has the lowest excitation of any known HH object, with S II-line/H-alpha = 12.