The Pulsation of χ Cygni Imaged by Optical Interferometry: A Novel Technique to Derive Distance and Mass of Mira Stars

  title={The Pulsation of $\chi$ Cygni Imaged by Optical Interferometry: A Novel Technique to Derive Distance and Mass of Mira Stars},
  author={Sylvestre Lacour and Eric Thi'ebaut and Guy Perrin and Serge Meimon and X. Haubois and Ettore Pedretti and Stephen T. Ridgway and John D. Monnier and J. P. Berger and Peter A. Schuller and H. Woodruff and A. Poncelet and Herv{\'e} Le Coroller and Rafael Millan-Gabet and Marc G. Lacasse and Wesley A. Traub},
  journal={The Astrophysical Journal},
We present infrared interferometric imaging of the S-type Mira star χ Cygni. The object was observed at four different epochs in 2005-2006 with the Infrared-Optical Telescope Array optical interferometer (H band). Images show up to 40% variation in the stellar diameter, as well as significant changes in the limb darkening and stellar inhomogeneities. Model fitting gave precise time-dependent values of the stellar diameter, and reveals presence and displacement of a warm molecular layer. The… 
Resolving asymmetries along the pulsation cycle of the Mira star X Hydrae
The mass-loss process in Mira stars probably occurs in an asymmetric way where dust can form in inhomogeneous circumstellar molecular clumps. Following asymmetries along the pulsation cycle can give
The Evolving Radio Photospheres of Long-period Variable Stars
Observations with the Karl G. Jansky Very Large Array at 46 GHz (7 mm) have been used to measure the size and shape of the radio photospheres of four long-period variable stars: R Leonis (R Leo),
Infrared Interferometric Three-dimensional Diagnosis of the Atmospheric Dynamics of the AGB Star R Dor with VLTI/AMBER
The mechanism of mass loss in late evolutionary stages of low- and intermediate-mass stars is not yet well understood. Therefore, it is crucial to study the dynamics of the region within a few
Milli-arcsecond images of the Herbig Ae star HD 163296
Context. The very close environments of young stars are the hosts of fundamental physical processes, such as planet formation, stardisk interactions, mass accretion, and ejection. The complex
We report on high-accuracy high-resolution (<20 mas) stellar observations obtained with the Palomar Fiber Nuller (PFN), a near-infrared (2.2 μm) interferometric coronagraph installed at the Palomar
Search for surface magnetic fields in Mira stars. First detection in χ Cygni
Context. So far, surface magnetic fields have never been detected on Mira stars. Only recently have the spectropolarimetric capabilities of measuring it via the Zeeman effect become available to us.
Evolved stars at high angular resolution: present and future
  • C. Paladini
  • Physics
    Astronomical Telescopes + Instrumentation
  • 2016
The late evolutionary stages of stellar evolution are a key ingredient for our understanding in many fields of astrophysics, including stellar evolution and the enrichment of the interstellar medium
Multiwavelength Period–Luminosity and Period–Luminosity–Color Relations at Maximum Light for Mira Variables in the Magellanic Clouds
We present Period-Luminosity and Period-Luminosity-Color relations at maximum-light for Mira variables in the Magellanic Clouds using time-series data from the Optical Gravitational Lensing
A HIFI preview of warm molecular gas around χ Cygni: First detection of H2O emission toward an S-type AGB star
Aims. A set of new, sensitive, and spectrally resolved, sub-millimeter line observations are used to probe the warm circumstellar gas around the S-type AGB star chi Cyg. The observed lines involve
Magnetic field in IRC+10216 and other C-Rich Evolved Stars
During the transition from the Asymptotic Giant Branch (AGB) to Planetary Nebulae (PN), the circumstellar geometry and morphology change dramatically. Another characteristic of this transition is the


The keck aperture masking experiment: Multiwavelength observations of six Mira variables
The angular diameters of six oxygen-rich Mira-type long-period variables have been measured at various NIR wavelengths using the aperture-masking technique in an extensive observing program from 1997
Tests of stellar model atmospheres by optical interferometry. IV. VINCI interferometry and UVES spec
Aims. We present coordinated near-infrared K-band interferometric and optical spectroscopic observations of the M 1.5 giant α Cet (Menkar) obtained with the instruments VINCI and UVES at the Paranal
Pre-maximum spectro-imaging of the Mira star T Leporis with AMBER/VLTI
Context. Diffuse envelopes around Mira variables are among the most important sources influencing the chemical evolution of galaxies. However they represent an observational challenge because of
Radio Photospheres of Long-Period Variable Stars
We report the detection of centimeter-wavelength emission from a sample of nearby long-period (Mira and semiregular) variables using the VLA. Six of the eight stars in the sample were detected. We
J, H, K spectro-interferometry of the Mira variable S Orionis
Aims. We present J, H, K spectrally dispersed interferometry with a spectral resolution of 35 for the Mira variable S Orionis. We aim at measuring the diameter variation as a function of wavelength
Many of the Mira stars observed with adequate spatial resolution show detectable asymmetry. This asymmetry can be caused by an asymmetric stellar photosphere and/or asymmetric envelope around the
Interferometric properties of pulsating C-rich AGB stars. Intensity profiles and uniform disc diamet
Aims. On the basis of a set of dynamic model atmospheres of C-rich AGB stars, we present the first theoretical study of centre-to-limb variation (CLV) properties and relative radius interpretation on
AGB variables and the Mira period–luminosity relation
Published data for large-amplitude asymptotic giant branch variables in the Large Magellanic Cloud (LMC) are re-analysed to establish the constants for an infrared (K) period-luminosity relation of
On the observability of geometric pulsation of M-type Mira variables
The geometric pulsation of an M-type Mira variable as a function of phase is studied by means of a series of complete self-excited models that follows two successive cycles with time intervals of
Variable Red Giants in the LMC: Pulsating Stars and Binaries?
  • P. Wood
  • Physics
    Publications of the Astronomical Society of Australia
  • 2000
Abstract Infrared J and K photometry has been obtained of all red giants in the half square degree region of the LMC bar searched for variables using the MACHO database byWood et al. (1999). The