The velocity distribution of interstellar titanium toward Zeta Persei

Observations of the interstellar 3384-A line of Ti II toward Zeta Persei are reported at a resolution of 1.4 km/s. This resolution exceeds by a factor of almost 3 that used in any previous observations of ions that are dominant stages of ionization in H I regions. Toward Zeta Per, two resolved line components of Ti II having widths generally comparable to those of the corresponding line components of trace ions K I, Ca II, and Na I are seen. For any other ions along this line of sight which have velocity distributions similar to that observed for Ti II, the critical equivalent width above which line saturation must be significant therefore does not exceed 14 mA for ultraviolet lines lying near 1200 A.