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Related papers: Quantitative spectroscopy of B-type supergiants

200 papers

Large-scale stellar surveys, such as SDSS-V, 4MOST, WEAVE, and PLATO, require accurate atmospheric models and synthetic spectra of stars for accurate analyses of fundamental stellar parameters and chemical abundances. The primary goal of…

Solar and Stellar Astrophysics · Physics 2024-07-15 Philipp Eitner , Maria Bergemann , Richard Hoppe , Åke Nordlund , Bertrand Plez , Jonas Klevas

We test our knowledge of the atomic opacity in the solar UV spectrum. Using the atomic data compiled in Paper I from modern, publicly available, databases, we perform calculations that are confronted with space-based observations of the…

Astrophysics · Physics 2009-11-07 C. Allende Prieto , I. Hubeny , D. L. Lambert

We investigate the impact of 3D hydrodynamical model atmospheres of red giant stars at different metallicities on the formation of spectral lines of a number of ions and molecules. We carry out realistic 3D simulations of surface convection…

Astrophysics · Physics 2009-11-13 Remo Collet , Martin Asplund , Regner Trampedach

We aim to provide new empirical clues about macroturbulent spectral line broadening in O- and B-type stars to evaluate its physical origin. We use high-resolution spectra of ~430 stars with spectral types in the range O4-B9 (all luminosity…

Solar and Stellar Astrophysics · Physics 2016-12-21 S. Simón-Díaz , M. Godart , N. Castro , A. Herrero , C. Aerts , J. Puls , J. Telting , L. Grassitelli

In this work we present first results of our current project aimed at combining the 3D hydrodynamical stellar atmosphere approach with non-LTE (NLTE) spectral line synthesis for a number of key chemical species. We carried out a full…

Solar and Stellar Astrophysics · Physics 2013-03-11 D. Prakapavicius , M. Steffen , A. Kucinskas , H. -G. Ludwig , B. Freytag , E. Caffau , R. Cayrel

We provide an extensive set of theoretical spectral energy distributions of massive stars derived from our "combined stellar structure and atmosphere models". The calculations covering the entire main sequence evolution for initial masses…

Astrophysics · Physics 2016-08-30 Daniel Schaerer , Alex de Koter

We present a mini-survey of Galactic B[e] stars mainly undertaken with the Large Binocular Telescope (LBT). B[e] stars show morphological features with hydrogen emission lines and an infrared excess, attributed to warm circumstellar dust.…

Solar and Stellar Astrophysics · Physics 2015-06-22 A. Liermann , O. Schnurr , M. Kraus , A. Kreplin , M. L. Arias , L. S. Cidale

Methods to determine abundances of the elements in the atmospheres of F, G, and K stars with precisions of 0.01-0.03 dex are reviewed. Such high-precision stellar abundances have led to the discovery of unexpected phenomena and relations…

Solar and Stellar Astrophysics · Physics 2018-11-06 Poul Erik Nissen , Bengt Gustafsson

We present non-local thermodynamic equilibrium (NLTE) line formation calculations for Ca I and Ca II in B-F stars. The sign and the magnitude of NLTE abundance corrections depend on line and stellar parameters. We determine calcium…

Solar and Stellar Astrophysics · Physics 2018-04-11 Tatyana Sitnova , Lyudmila Mashonkina , Tatyana Ryabchikova

The precise analysis of properties of planetary nebulae is strongly dependent on good models for the stellar ionizing spectrum. Observations in the UV - X-ray wavelength range as well as NLTE model atmosphere calculations of spectra of…

Astrophysics · Physics 2009-11-07 Thomas Rauch

We have undertaken quantitative analysis of four LMC and SMC O4--9.7 extreme supergiants using far-ultraviolet FUSE, ultraviolet IUE/HSTand optical VLT UVES spectroscopy. Extended, non-LTE model atmospheres that allow for the consistent…

Astrophysics · Physics 2009-11-07 P. A. Crowther , D. J. Hillier , C. J. Evans , A. W. Fullerton , O. De Marco , A. J. Willis

In this review given at the Hot and Cool: Bridging Gaps in Massive Star Evolution conference, I present the state of the art in red supergiant star atmosphere modelling. The last generation of hydrostatic 1D LTE MARCS models publicly…

Solar and Stellar Astrophysics · Physics 2009-03-23 Bertrand Plez

Iron plays a crucial role in studies of late-type stars. In their atmospheres, Fe I is the minority species and its lines are subject to the departures from LTE. In contrast, one believes that LTE is a realistic approximation for Fe II…

Solar and Stellar Astrophysics · Physics 2019-10-23 Lyudmila Mashonkina , Tatyana Sitnova , Svetlana A. Yakovleva , Andrey K. Belyaev

Modern spectroscopy of early-type stars often aims at studying complex physical phenomena. Comparatively less attention is paid to identifying and studying the "normal" A- and B-type stars and testing how the basic atomic parameters and…

Solar and Stellar Astrophysics · Physics 2015-05-13 L. Fossati , T. Ryabchikova , S. Bagnulo , E. Alecian , J. Grunhut , O. Kochukhov , G. Wade

We present photometric and spectroscopic analyses of gravity (g-mode) long-period pulsating hot subdwarf B (sdB) stars. We perform a detailed asteroseismic and spectroscopic analysis of five pulsating sdB stars observed with {\it TESS}…

Non-local thermodynamical equilibrium (NLTE) line formation for Mg I and Mg II lines is considered in classical 1D-LTE model atmospheres of the Sun and 17 stars with reliable atmospheric parameters and in a broad range of spectral types:…

Solar and Stellar Astrophysics · Physics 2018-10-31 Sofya Alexeeva , Tatiana Ryabchikova , Lyudmila Mashonkina , Shaoming Hu

Aiming at testing the validity of our magnesium atomic model and investigating the effects of non-local thermodynamical equilibrium (NLTE) on the formation of the H-band neutral magnesium lines, we derive the differential Mg abundances from…

Solar and Stellar Astrophysics · Physics 2017-01-25 Junbo Zhang , Jianrong Shi , Kaike Pan , Carlos Allende Prieto , Chao Liu

We present accurate methods of abundance determination based on the non-local thermodynamic equilibrium (NLTE) line formation for carbon, oxygen, calcium, titanium, and iron in the atmospheres of BAF-type stars. For C I-II, O I, Ca I-II,…

Solar and Stellar Astrophysics · Physics 2018-08-22 Tatyana Sitnova , Tatyana Ryabchikova , Sofya Alexeeva , Lyudmila Mashonkina

We determine Mg abundances in 6 Gaia benchmark stars using theoretical one-dimensional (1D) hydrostatic model atmospheres, as well as temporally- and spatially-averaged 3D model atmospheres (<3D>). The stars cover a range of Teff from 4700…

Solar and Stellar Astrophysics · Physics 2017-09-27 Maria Bergemann , Remo Collet , Anish M. Amarsi , Mikhail Kovalev , Gregory Ruchti , Zazralt Magic

In Schaerer et al. (1995, Paper I) we have presented the first "combined stellar structure and atmosphere models" (CoStar) for massive stars, which consistently treat the entire mass loosing star from the center out to the outer region of…

Astrophysics · Physics 2007-05-23 D. Schaerer , A. de Koter , W. Schmutz , A. Maeder