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Related papers: iSTARMOD: A Python Code to Quantify Chromospheric …

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We present new spectroscopic observations in the Ca~{\sc ii} H \& K line region for a sample of 28 chromospherically active binary systems (RS$~$CVn and BY$~$Dra classes), with different activity levels. By using the spectral subtraction…

Astrophysics · Physics 2007-05-23 D. Montes , E. De Castro , M. J. Fernandez-Figueroa , M. Cornide

Aims: We present a compilation of spectroscopic data from a survey of 144 chromospherically active young stars in the solar neighborhood which may be used to investigate different aspects of the formation and evolution of the solar…

Measuring coverage of dark spots on cool stars is important in understanding how stellar magnetic activity scales with the rotation rate and convection zone depth. In this respect, it is crucial to infer surface magnetic patterns on G and K…

Solar and Stellar Astrophysics · Physics 2023-10-24 Engin Bahar , Hakan V. Şenavcı , Emre Işık , Gaitee A. J. Hussain , Oleg Kochukhov , David Montes , Yue Xiang

Effective temperatures, surface gravities, and iron abundances were derived for 109 stars observed by the K2 mission using equivalent width measurements of Fe I and Fe II lines. Calculations were carried out in LTE using Kurucz model…

Solar and Stellar Astrophysics · Physics 2024-07-19 V. Loaiza-Tacuri , Katia Cunha , Verne V. Smith , F. Quispe-Huaynasi , Ellen Costa-Almeida , Luan Ghezzi , Jorge Melendez

Sky subtraction is the key technique in data reduction of multi-fiber spectra. Knowledge of the related instrument character is necessary to determine the method adopted in sky subtraction. In this study, we described the sky subtraction…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 Zhong-Rui Bai , Hao-Tong Zhang , Hai-Long Yuan , Guang-Wei Li , Jian-Jun Chen , Ya-Juan Lei , Hui-Qin Yang , Yi-Qiao Dong , Gang Wang , Yong-Heng Zhao

The dependence of stellar magnetic activity on stellar parameters would be inspired by the chromospheric activity studies based on the large-scale spectroscopic surveys. The Ca II H and K lines are employed to construct indicators for…

Solar and Stellar Astrophysics · Physics 2024-07-31 Weitao Zhang , Jun Zhang , Han He , Ali Luo , Haotong Zhang

Stellar atmosphere modelling predicts the luminosity and temperature of a star, together with parameters such as the effective gravity and the metallicity, by reproducing the observed spectral energy distribution. Most observational data…

Instrumentation and Methods for Astrophysics · Physics 2024-02-21 Iain McDonald , Albert A. Zijlstra , Nick L. J. Cox , Emma L. Alexander , Alexander Csukai , Ria Ramkumar , Alexander Hollings

Chromospheric modeling of observed differences in stellar activity lines is imperative to fully understand the upper atmospheres of late-type stars. We present one-dimensional parametrized chromosphere models computed with the atmosphere…

The Gaia Radial Velocity Spectrometer provides the unique opportunity of a spectroscopic analysis of millions of stars at medium-resolution in the near-infrared. This wavelength range includes the Ca II infrared triplet (IRT), which is a…

The CARMENES survey is searching for Earth-like planets orbiting M dwarfs using the radial velocity method. Studying the stellar activity of the target stars is important to avoid false planet detections and to improve our understanding of…

We present measurements of the auto- and cross-frequency power spectra of the cosmic infrared background (CIB) at 250, 350, and 500um (1200, 860, and 600 GHz) from observations totaling ~ 70 deg^2 made with the SPIRE instrument aboard the…

Context. Medium-resolution IFS, such as MUSE at the VLT, are equipped to detect the emission lines of faint accreting companions when associated with dedicated stellar halo subtraction methods. We recently proposed a new approach based on…

Instrumentation and Methods for Astrophysics · Physics 2025-11-26 R. Julo , M. Bonnefoy , F. Chatelain , O. Flasseur , O. J. J. Michel , S. Jorquera , P. Delorme , G. Chauvin

The light emitted from the stellar photosphere serves as a unique signature for the nature of stars. The behaviour of these stellar lines depend upon the surface temperature, mass, evolutionary status and chemical composition of the star.…

Solar and Stellar Astrophysics · Physics 2016-10-25 Priyanka Chaturvedi , Abhijit Chakraborty , B. G. Anandarao

This is the first paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. Simultaneous H{alpha}, Na I D{1}, D{2}, and He I D{3} spectroscopic…

Astrophysics · Physics 2009-10-30 D. Montes , M. J. Fernandez-Figueroa , E. De Castro , J. Sanz-Forcada

Mode identification is crucial for an asteroseismological study of any significance. Contrarily to spectroscopic techniques, methods such as period-fitting and multi-colour photometry do not provide a full reconstruction of non-radial…

Astrophysics · Physics 2008-04-29 C. Schoenaers , A. E. Lynas-Gray

Stellar activity cycles are the manifestation of dynamo process running in the stellar interiors. They have been observed during years to decades thanks to the measurement of stellar magnetic proxies at the surface of the stars such as the…

Solar and Stellar Astrophysics · Physics 2015-06-12 S. Mathur , R. A. Garcia , A. Morgenthaler , D. Salabert , P. Petit , J. Ballot , C. Regulo , C. Catala

To reveal details of the internal structure, the relationship between chromospheric activity and the Rossby number has been extensively examined for main-sequence stars. For active pre-main sequence (PMS) stars, it is suggested that the…

Solar and Stellar Astrophysics · Physics 2024-11-27 Mai Yamashita , Yoichi Itoh , Yuhei Takagi

Measurements of the star formation activity on cloud scales are fundamental to uncovering the physics of the molecular cloud, star formation, and stellar feedback cycle in galaxies. Infrared (IR) emission from small dust grains and…

$\require{mediawiki-texvc}$A stellar chromospheric activity database of solar-like stars is constructed based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low-Resolution Spectroscopic Survey (LRS). The database…

Solar and Stellar Astrophysics · Physics 2022-11-16 Weitao Zhang , Jun Zhang , Han He , Zhiping Song , Ali Luo , Haotong Zhang

Synthetic-template subtraction is widely used to measure chromospheric activity in large spectroscopic surveys. However, many solar-like FGK stars show systematically negative Ca II infrared triplet (IRT) residual indices, implying that the…

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