D. Barthes, PULSATION MODES OF MIRA STARS AND QUESTIONING OF LINEAR MODELING - INDICATIONS FROM HIPPARCOS AND THE LMC, Astronomy and astrophysics, 333(2), 1998, pp. 647-657
Thorough discussion of the previous theoretical works on the pulsation
of Long Period Variables leads us to the conclusion that the mode per
iods predicted by linear models must significantly differ from the rea
lity, and that, if one nevertheless relies upon such a modelling, it i
s at least necessary to change the mixing length. The hypothesis that
the so-derived mode periods be reasonably reliable is supported by con
frontation between a model grid based on these grounds and the luminos
ities of LPVs in the Large Magellanic Cloud and in LMC clusters, as we
ll as the luminosities and effective temperatures of Miras in the sola
r neighbourhood. A wide majority of the Miras appear probably pulsatin
g on the first overtone, and the sample Semi-Regulars on the second. H
owever, a significant proportion of Miras seem to be fundamental pulsa
tors. Individual masses are derived. A few stars are probably undergoi
ng hot bottom burning, while two seem to have a peculiar dust envelope
.