  We propose the application of laser cooling to a number of transition-metal
atoms, allowing numerous bosonic and fermionic atomic gases to be cooled to
ultra-low temperatures. The non-zero electron orbital angular momentum of these
atoms implies that strongly atom-state-dependent light-atom interactions occur
even for light that is far-detuned from atomic transitions. At the same time,
many transition-metal atoms have small magnetic dipole moments in their
low-energy states, reducing the rate of dipolar-relaxation collisions.
Altogether, these features provide compelling opportunities for future
ultracold-atom research. Focusing on the case of atomic titanium, we identify
the metastable $a ^5F_5$ state as supporting a $J \rightarrow J+1$ optical
transition with properties similar to the D2 transition of alkali atoms, and
suited for laser cooling. The high total angular momentum and electron spin of
this state suppresses leakage out of the the nearly closed optical transition
to a branching ratio estimated below $\sim 10^{-5}$. Following the pattern
exemplified by titanium, we identify optical transitions that are suited for
laser cooling of elements in the scandium group (Sc, Y, La), the titanium group
(Ti, Zr), the vanadium group (V, Nb), the manganese group (Mn, Tc), and the
iron group (Fe, Ru).
