Mira-type stars are luminous red giants that have pulsation periods that last anywhere between 100 and 700 days. The irregular behavior of their periods and atmospheric properties flag them as excellent candidates for astrophysical studies of non-spherical stars. This paper focuses on the linear polarization of light emitted from three Mira-type stars: Mira itself, R Leo, and V CVn. Polarimetri...

Recent observations of the Mira AB binary system have revealed a surrounding arc-like structure and a stream of material stretching 2 degrees away in opposition to the arc. The alignment of the proper motion vector and the arc-like structure shows the structures to be a bow shock and accompanying tail. We have successfully hydrodynamically modelled the bow shock and tail as the interaction betw...

We present angular size measurements of 22 oxygen-rich Mira variable stars. These data are part of a long term observational program using the Infrared Optical Telescope Array (IOTA) to characterize the observable behavior of these stars. Complementing the infrared angular size measurements, values for variable star phase, spectral type, bolometric flux and distance were established for stars i...

Stellar evolution theory predicts that asymptotic giant branch stars undergo a series of short thermal pulses that significantly change their luminosity and mass on timescales of hundreds to thousands of years. These pulses are confirmed observationally by the existence of the short-lived radioisotope technetium in the spectra of some of these stars, but other observational consequences of ther...

In this paper we present a new estimate of the effective temperatures of 32 giant stars in the spectral range K0 to M10. The sample includes also 4 Mira stars. The temperatures are based on a homogeneous set of angular diameters obtained by our group by the technique of lunar occultations, and using a photometric and spectroscopic coverage with a combination of original measurements and literat...

TheMiraAB system is a nearby ( 107 pc) example of awind accreting binary star system. In this class of system, the wind from amass-losing red giant star (Mira A) is accreted onto a companion (Mira B), as indicated by an accretion shock signature in spectra at ultraviolet and X-ray wavelengths. Using novel imaging techniques, we report the detection of emission at mid-infrared wavelengths betwee...

The angular diameters of six oxygen rich Mira-type long-period variables have been measured at various near-infrared (NIR) wavelengths using the aperture masking technique in an extensive observing program from 1997 Jan to 2004 Sep. These data sets span many pulsation cycles of the observed objects and represent the largest study of multi-wavelength, multi-epoch interferometric angular diameter...

Since being named 'wonderful' in the seventeenth century for its peculiar brightness variability, Mira A has been the subject of extensive research and become the prototype for a whole class of 'Mira' variable stars. The primary star in a binary system, Mira A is reaching the end of its life and currently undergoing an extended period of enhanced mass loss. Recent observations have revealed a s...

For a complete 12 μm flux-limited sample of 207 IRAS sources (F12 ≥ 150 Jy, |b| ≥ 5), the majority of which are AGB stars (∼87%), we have extracted light curves in seven infrared bands between 1.25 μm − 60 μm using the database of the Diffuse Infrared Background Experiment (DIRBE) instrument on the Cosmic Background Explorer (COBE) satellite. Using previous infrared surveys, we filtered these l...

Our understanding of large amplitude pulsating stars and their status in stellar evolution is briefly reviewed. The paper then describes the near-infrared light curves of various asymptotic giant branch stars, concentrating on possible evidence for changing mass-loss rates. The stars discussed include oxygenand carbon-rich Miras, OH/IR stars, thick-shelled carbon stars and symbiotic Miras. Fina...