1999A&A...341..224L

Time-series 2.0-2.5µm infrared spectra have been observed for Miras with periods less than 200 days. Some of these stars are high velocity and metal poor. We have also observed the peculiar, possibly metal-poor Mira, Z Oph. Velocities, excitation temperatures, and ¹²C/¹³C have been determined for these stars. These results are compared with similar data for bright, field Miras. We find Z Oph to be a metal-poor Mira of very low mass-loss rate. All Miras regardless of period, metallicity, or chemical abundance have the same pulsation velocity amplitude. The mode of pulsation is discussed.