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Astron. Astrophys. 317, 761-768 (1997)
Determination of Miras temperatures from TiO and VO bands. Estimates of distances *
R. Alvarez and
M.-O. Mennessier
GRAAL cc072, UPRESA 5024 CNRS/UMII, Université
Montpellier II, F-34095 Montpellier Cedex 05, France
Received 25 January 1996 / Accepted 13 June 1996
Abstract
Effective temperatures are determined for a sample of 165
oxygen-rich Miras using indices related to molecular band strength of
titanium oxide and vanadium oxide computed from narrow-band photometry
observations. We find a clear although very scattered
period-temperature relation which agrees with a previous one. Using a
theoretical evolutionary track on AGB and assuming that the scatter
around the period-temperature relation is due to mass differences, we
can obtain a period-luminosity relation similar to the one observed in
the LMC if the mass range is 0.8 to 2.6 ![[FORMULA]](img1.gif)
. Effects
of metallicity are discussed. The determined luminosities are used to
calibrate distances that are compared to several other
estimations.
Key words: stars:
atmospheres 
stars:
distances
stars: fundamental
parameters
stars: AGB and post-AGB
* Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
Send offprint requests to: R. Alvarez, alvarez@graal.univ-montp2.fr
Contents
- 1. Introduction
- 2. Observations
- 3. TiO and VO indices as temperature indicators
- 4. Application to Miras. Period-temperature relationship
- 5. Luminosities and mass range
- 6. Distance estimates
- 7. Conclusions
- Acknowledgements
- References
© European Southern Observatory (ESO) 1997
Online publication: July 8, 1998
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