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Related papers: Dynamical Opacity-Sampling Models of Mira Variable…

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We describe the Cool Opacity-sampling Dynamic EXtended (CODEX) atmosphere models of Mira variable stars, and examine in detail the physical and numerical approximations that go in to the model creation. The CODEX atmospheric models are…

Astrophysics · Physics 2009-11-13 M. J. Ireland , M. Scholz , P. R. Wood

We obtained a total of 20 near-infrared K-band spectro-interferometric snapshot observations of the Mira variables o Cet, R Leo, R Aqr, X Hya, W Vel, and R Cnc with a spectral resolution of about 1500. We compared observed flux and…

Solar and Stellar Astrophysics · Physics 2016-02-17 M. Wittkowski , A. Chiavassa , B. Freytag , M. Scholz , S. Hoefner , I. Karovicova , P. A. Whitelock

The formation of dust with temperature-dependent non-grey opacity is considered in a series of self-consistent model atmospheres at different phases of an O-rich Mira variable of mass 1.2 $M_\odot$. Photometric and interferometric…

Astrophysics · Physics 2009-11-11 M. J. Ireland , M. Scholz

Our comprehension of stellar evolution on the AGB still faces many difficulties. To improve on this, a quantified understanding of large-amplitude pulsator atmospheres and interpretation in terms of their fundamental stellar parameters are…

Solar and Stellar Astrophysics · Physics 2015-06-03 M. Hillen , T. Verhoelst , P. Degroote , B. Acke , H. van Winckel

We present a comparison of dynamical model atmospheres with mid-infrared (~11 micron) interferometric and spectroscopic observations of the Mira variable o Cet. The dynamical model atmospheres of Mira variables pulsating in the fundamental…

Astrophysics · Physics 2009-11-11 K. Ohnaka , M. Scholz , P. R. Wood

Aims. We study the effects of moderate deviations from solar abundances upon the atmospheric structure and colours of typical Mira variables. Methods. We present two model series of dynamical opacity-sampling models of Mira variables which…

Solar and Stellar Astrophysics · Physics 2015-06-19 Michael Scholz , Michael J. Ireland , Peter R. Wood

Context. We study the atmosphere of the carbon-rich Mira RU Vir using the mid-infrared high spatial resolution interferometric observations from VLTI/MIDI. Aims. The aim of this work is to analyse the atmosphere of the carbon-rich Mira RU…

Solar and Stellar Astrophysics · Physics 2015-11-04 G. Rau , C. Paladini , J. Hron , B. Aringer , M. A. T. Groenewegen , W. Nowotny

We present the first multi-epoch study that includes concurrent mid-infrared and radio interferometry of an oxygen-rich Mira star. We obtained mid-infrared interferometry of S Ori with VLTI/MIDI at four epochs between December 2004 and…

Astrophysics · Physics 2007-07-04 M. Wittkowski , D. A. Boboltz , K. Ohnaka , T. Driebe , M. Scholz

We have modelled the circumstellar envelope of {\it o} Ceti (Mira) using new observational constraints. These are obtained from photospheric light scattered in near-IR vibrational-rotational lines of circumstellar CO molecules at 4.6…

Astrophysics · Physics 2009-10-31 N. Ryde , F. L. Schoeier

The prototypical Mira variable, $o$ Cet (Mira), has been observed as a Science Verification target in the 2014 ALMA Long Baseline Campaign with a longest baseline of 15 km. ALMA clearly resolves the images of the continuum and molecular…

Solar and Stellar Astrophysics · Physics 2016-06-01 K. T. Wong , T. Kamiński , K. M. Menten , F. Wyrowski

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 their complex spectral features and their rapid…

Solar and Stellar Astrophysics · Physics 2009-11-13 Jean-Baptiste Le Bouquin , Sylvestre Lacour , Stephanie Renard , Eric Thiebaut , Antoine Merand , Tijl Verhoelst

Pulsation models are crucial for the interpretation of spectrophotometric and interferometric observations of Mira variables. Comparing predicted and observed spectra is one way of establishing the validity of such models. In this paper, we…

Astrophysics · Physics 2009-11-10 A. Tej , A. Lancon , M. Scholz , P. R. Wood

Modeling stellar atmospheres is a complex, intriguing task in modern astronomy. A systematic comparison of models with multi-technique observations is the only efficient way to constrain them. Aims: We performed a self-consistent modeling…

Solar and Stellar Astrophysics · Physics 2017-04-12 Gioia Rau , Josef Hron , Claudia Paladini , Benard Aringer , Kjell Eriksson , Paola Marigo , Walter Nowotny , Rebekka Grellmann

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…

A survey of CO(3-2) emission from optically visible oxygen-rich Mira variable stars within 500 pc of the sun was conducted. A molecular envelope was detected surrounding 36 of the 66 stars examined. Some of these stars have lower outflow…

Astrophysics · Physics 2009-10-28 K. Young

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 observational data to diameter-type quantities and of…

Astrophysics · Physics 2015-06-24 Michael Scholz

With the help of model calculations we aim at reproducing the observational photometric findings for a large sample of well-characterised galactic C-type Mira variables losing mass at different rates. We used dynamic model atmospheres,…

Solar and Stellar Astrophysics · Physics 2015-06-15 W. Nowotny , B. Aringer , S. Hoefner , K. Eriksson

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 two perpendicular polarisations, the…

Astrophysics · Physics 2009-11-11 M. J. Ireland , P. G. Tuthill , J. Davis , W. Tango

We report imaging observations of the symbotic long-period Mira variable R Aquarii (R Aqr) at near-infrared and radio wavelengths. The near-infrared observations were made with the IOTA imaging interferometer in three narrow-band filters…

Mira variables share essential characteristics: High visual amplitude, periods of hundreds of days, red colors (spectral types M, S, and C), and the presence of emission lines at some phases. They are fundamental mode pulsators, with…

Solar and Stellar Astrophysics · Physics 2012-07-18 Lee Anne Willson , Massimo Marengo
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