The Jet and Energy Source of HH 34.

We have discovered a highly collimated optical jet emanating from a faint star and pointing towards the Herbig-Haro object HH 34. The jet consists of six knots extending over about 16 arcseconds, which at a distance of 500 pc corresponds to about 8000 AU. At very low light levels the jet can be followed for 9" -10" to a faint emission line star, which we identify as the energy source. Low and high resolution spectra show that the jet is shock-excited with a characteristic low-excitation emission-line spectrum. The red sulfur lines are extremely strong, with a lambda6717/Halpha ratio of 2.9. The electron density derived from the sulfur line ratio is around 10(3). The jet is a high-velocity object with a heliocentric radial velocity of about -60 km/sec.