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Related papers: Mira Variable Stars From LAMOST DR4 Data: Emission…

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We present a sample of 4,132 Mira-like variables (red variables with long periods and high amplitudes) in the Kilodegree Extremely Little Telescope (KELT) survey. Of these, 814 are new detections. We used 2MASS colors to identify candidate…

We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which…

Solar and Stellar Astrophysics · Physics 2015-06-05 Warren A. Reid , Quentin A. Parker

(abridged) The 222000 I-band light curves of variable stars detected by the OGLE-II survey in the direction of the Galactic Bulge have been fitted and have also been correlated with the DENIS and 2MASS databases. Results are presented for…

Astrophysics · Physics 2009-11-11 M. A. T. Groenewegen , J. A. D. L. Blommaert

The knowledge of the structure and dynamics of AGB-star atmospheres is crucial to better understand the mass loss. The tomographic method, that relies on the design of spectral masks containing lines forming in given ranges of optical…

An analysis of H alpha and H beta spectra in a sample of 30 cool dwarf and subgiant stars is presented using MARCS model atmospheres based on the most recent calculations of the line opacities. A detailed quantitative comparison of the…

The outflows of oxygen-rich asymptotic giant branch (AGB) stars are thought to be driven by radiation pressure by photon scattering on grains with sizes of tenths of microns. The details of the formation of dust in the extended atmospheres…

Solar and Stellar Astrophysics · Physics 2018-12-05 T. Khouri , W. H. T. Vlemmings , H. Olofsson , C. Ginski , E. De Beck , M. Maercker , S. Ramstedt

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

The Lyman-alpha emission line dominates the far-ultraviolet spectra of late-type stars and is a major source for photodissociation of important molecules including H2O, CH4, and CO2 in exoplanet atmospheres. The incident flux in this line…

Solar and Stellar Astrophysics · Physics 2015-06-12 Jeffrey L. Linsky , Kevin France , Tom Ayres

Dynamic model atmospheres of Mira stars predict variabilities in the photospheric radius and in atmospheric molecular layers which are not yet strongly constrained by observations. Here we measure the variability of the oxygen-rich Mira…

Solar and Stellar Astrophysics · Physics 2018-06-06 M. Wittkowski , G. Rau , A. Chiavassa , S. Hoefner , M. Scholz , P. R. Wood , W. J. de Wit , F. Eisenhauer , X. Haubois , T. Paumard

Miras are fascinating stars. A kappa-mechanism in their atmosphere drives pulsations which produce changes in their photometric brightness, apparent spectral type and effective temperature. These pulsations also drive the formation of…

Solar and Stellar Astrophysics · Physics 2022-12-20 David Boyd

We comprehensively study the variability of Miras in the Large Magellanic Cloud (LMC) by simultaneous analysing light curves in 14 bands in the range of 0.5$-$24 microns. We model over 20-years-long, high cadence $I$-band light curves…

The kinematic and Period-Luminosity-Colour distribution of O-rich Long-Period Variable stars of the solar neighbourhood is interpreted in terms of pulsation modes, masses and metallicities. It is first shown that, because of input physics…

Astrophysics · Physics 2009-10-31 D. Barthes , X. Luri

We describe the time-dependent properties of a new spectroscopically confirmed Mira variable, which was discovered in 2013 as MASTER-Net Optical Transient (OT) J212444.87+321738.3 towards the Cygnus constellation. We have performed…

Solar and Stellar Astrophysics · Physics 2018-05-16 Supriyo Ghosh , Soumen Mondal , Ramkrishna Das , D. P. K. Banerjee , N. M. Ashok , Franz-Josef Hambsch , Somnath Dutta

We report photometric observations in Johnson UBV bands of the short term variability of Mira. The amplitude detected is 0.16 mag in B band. Adopting interstellar extinction E(B-V)=0, we find for the flickering source colour B-V=1.3,…

Solar and Stellar Astrophysics · Physics 2019-04-02 R. Zamanov , S. Boeva , B. Spassov , G. Latev , U. Wolter , K. A. Stoyanov

Infrared and optical photometric and spectroscopic observations of the symbiotic nova RR Tel are used to study the effects and properties of dust in symbiotic binaries containing a cool Mira component, as well as showing "obscuration…

Aims: Our aim is to identify the dominant molecular cooling lines and characteristic emission features in the 1.3 mm window of distinct regions in the northern part of the Orion A molecular cloud. By defining and analysing template regions,…

Astrophysics of Galaxies · Physics 2020-04-15 N. Brinkmann , F. Wyrowski , J. Kauffmann , D. Colombo , K. M. Menten , X. D. Tang , R. Güsten

We have obtained HST and ground-based observations of a sample of 20 O-type stars in the LMC and SMC, including six of the hottest massive stars known (subtypes O2-3) in the R136 cluster. In general, these data include (a) the HST UV…

We report on our observing program to capture simultaneous spectra of Ca II and Balmer lines in a sample of nearby M3 dwarfs. Our goal is to investigate the chromospheric temperature structure required to produce these lines at the observed…

Astrophysics · Physics 2009-11-13 Lucianne M. Walkowicz , Suzanne L. Hawley

The VISTA Variables in the Via Lactea (VVV) survey obtained near-infrared photometry toward the Galactic bulge and the southern disc plane for a decade (2010 - 2019). We designed a modified Lomb-Scargle method to search for large-amplitude…

Low-mass emission-line stars belong to various evolutionary stages, from pre-main-sequence young stars to evolved stars. In this work, we present a catalog of late-type (F0 to M9) emission-line stars from the LAMOST Data Release 6. Using…

Solar and Stellar Astrophysics · Physics 2024-10-24 D. Edwin , Blesson Mathew , B. Shridharan , Vineeth Valsan , S. Nidhi , Suman Bhattacharyya , Sreeja S. Kartha , T. Robin