Multiwavelength diameters of nearby Miras and semiregular variables

  title={Multiwavelength diameters of nearby Miras and semiregular variables},
  author={M. Ireland and P. Tuthill and T. Bedding and J. Robertson and A. Jacob},
  journal={Monthly Notices of the Royal Astronomical Society},
ABSTRACT We have used optical interferometry to obtain multi-wavelength visibility curves for eightred giants over the wavelength range 650–1000 nm. The observations consist of wavelength-dispersed fringes recorded with MAPPIT (Masked APerture-Plane Interference Telescope) atthe 3.9-mAnglo-AustralianTelescope.We present results for fourMiras (R Car, oCet, R Hya,R Leo) and four semi-regularvariables (R Dor, W Hya, L 2 Pup, γ Cru). All stars except γ Crushow strong variations of angular size with… Expand
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 1997Expand
We present results from a spectro-interferometric study of the Miras o Cet, R Leo, and W Hya obtained with the Keck Aperture Masking Experiment from 1998 September to 2002 July. The spectrallyExpand
An edge-on translucent dust disk around the nearest AGB star, L2 Puppis - VLT/NACO spectro-imaging from 1.04 to 4.05 μm and VLTI interferometry
As the nearest known AGB star (d=64pc) and one of the brightest (mK~-2), L2 Pup is a particularly interesting benchmark object to monitor the final stages of stellar evolution. We report new luckyExpand
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),Expand
The mid-infrared diameter of W Hydrae ,
Aims. Asymptotic giant branch (AGB) stars are among the largest distributors of dust into the interstellar medium, and it is therefore important to understand the dust formation process and sequenceExpand
VLBA SiO observations of bright O-rich AGB stars
We present the results of observations of the SiO masers at 7 mm wavelength in several oxygen rich Asymptotic Giant Branch (AGB) stars. These observations were coordinated with observations using theExpand
AMBER-NACO aperture-synthesis imaging of the half-obscured central star and the edge-on disk of the red giant L2 Pup
The red giant L2 Pup started a dimming event in 1994, which is considered to be caused by the ejection of dust clouds. We present near-IR aperture-synthesis imaging of L2 Pup achieved by combiningExpand
Dissecting the AGB star L-2 Puppis: a torus in the making
Aims. The circumstellar environment of L-2 Pup, an oxygen-rich semiregular variable, was observed to understand the evolution of mass loss and the shaping of ejecta in the late stages of stellarExpand
Dust scattering in the Miras R Car and RR Sco resolved by optical interferometric polarimetry
We present optical interferometric polarimetry measurements of the Mira-like variables R Car and RR Sco, using the Sydney University Stellar Interferometer. By making visibility measurements in twoExpand
Resolving the extended stellar atmospheres of Asymptotic Giant Branch stars at (sub-)millimetre wavelengths
The initial conditions for the mass loss during the Asymptotic Giant Branch (AGB) phase are set in their extended atmospheres, where, among others, convection and pulsation driven shocks determineExpand


Mira science with interferometry: a review
  • M. Scholz
  • Physics, Engineering
  • SPIE Astronomical Telescopes + Instrumentation
  • 2003
Model-predicted and observed properties of the brightness distribution on M-type Mira disks are discussed. Fundamental issues of limb-darkening and diameter definition, of assigning observationalExpand
Infrared colours for Mira-like long-period variables found in the Catalogue
Near-infrared, JHKL, photometry is presented for 193 Mira and semi-regular variables that were observed by Hipparcos; periods, bolometric magnitudes and amplitudes are derived for 92 of them. BecauseExpand
Effects of molecular contamination of IR near‐continuum bandpasses on measurements of M‐type Mira diameters
We study the contamination of six near-continuum bandpasses (0.82, 0.92 and 1.04 μm, H, K, L*) that are commonly used for interferometric measurement of diameters of M-type Mira variables.Expand
Bootstrapping the NPOI: keeping long baselines in phase by tracking fringes on short baselines
The high-spatial-frequency fringes that contain detailed information about a stellar image are generally too weak to track. The Navy Prototype Optical Interferometer (NPOI) is the firstExpand
Multi-wavelength bispectrum speckle interferometry of R Leo and comparison with Mira star models
We present diffraction-limited (30 mas resolution) bispectrum speckle interferometry of the Mira star R Leo with the 6 m SAO telescope. The speckle interfero grams were recorded through narrow-bandExpand
How many Hipparcos Variability-Induced Movers are genuine binaries?
Hipparcos observations of some variable stars, and especially of long-period (e.g. Mira) variables, reveal a motion of the photocenter correlated with the brightness variation (variability-inducedExpand
The light curve of the semiregular variable L2 Puppis – I. A recent dimming event from dust
The nearby Mira-like variable L2 Pup is shown to be undergoing an unprecedented dimming episode. The stability of the period rules out intrinsi c changes to the star, leaving dust formation along theExpand
Mode switching in the nearby Mira-like variable R Doradus
ABSTRA C T We discuss visual observations spanning nearly 70 years of the nearby semiregular variable R Doradus. Using wavelet analysis, we show that the star switches back and forth between twoExpand
Stellar radii of M giants
Abstract We determine the stellar radii of the M giant stars in the Hipparcos catalogue3 that have a parallax measured to better than 20% accuracy. This is done with the help of a relation between aExpand
The angular diameter of R Doradus: a nearby Mira-like star
We find the angular diameter of R Doradus to be 57 ± 5 mas, exceeding that of Betelgeuse and implying that R Dor is larger in apparent size than every star except the Sun. R Dor is shown to beExpand