R. Alvarez et al., OXYGEN-RICH MIRA VARIABLES - NEAR-INFRARED LUMINOSITY CALIBRATIONS - POPULATIONS AND PERIOD-LUMINOSITY RELATIONS, Astronomy and astrophysics, 327(2), 1997, pp. 656-661
HIPPARCOS astrometric and kinematical data of oxygen-rich Mira variabl
es are used to calibrate absolute near-infrared magnitudes and kinemat
ic parameters. Two sets of near-infrared magnitudes compiled from diff
erent authors are used: broad-band K and narrow-band photometric measu
rements at 1.04 mu m (104 filter). Three distinct classes of stars wit
h different kinematics and scale height have been identified. The two
most significant groups present characteristics close to the ones usua
lly assigned to extended/thick disk-halo population and old disk popul
ation respectively, and thus they might differ by their metallicity ab
undance. They exhibit different period distributions, as expected if t
hese two groups actually correspond to populations of distinct initial
masses, ages and metallicities. Two parallel period-luminosity relati
ons are found in K as well as in 104, one for each significant populat
ion. The shift between these relations is interpreted as the consequen
ce of the effects of metallicity abundance on the luminosity.