English
Related papers

Related papers: Stellar activity with LAMOST - II. Chromospheric a…

200 papers

We present the results of a 5 month photometric time-series survey for stellar rotation over a 40'x40' field on the 150 Myr open cluster M35. We report rotation periods for 441 stars and determine their cluster membership and binarity based…

Astrophysics · Physics 2011-02-11 Søren Meibom , Robert D. Mathieu , Keivan G. Stassun

We monitored the chromospheric activity in the Ca II H & K lines of 13 solar-type stars (including the Sun); 8 of them over three years at the CFHT and 5 in a single run at the VLT. Ten of the 13 targets have close planetary companions. All…

Astrophysics · Physics 2009-11-10 E. Shkolnik , G. A. H. Walker , D. A. Bohlender , P. -G. Gu , M. Kürster

Obtaining measurements of chromospheric and photometric activity of stars with near-solar fundamental parameters and rotation periods is important for a better understanding of solar-stellar connection. We select a sample of 2603 stars with…

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…

Context: Chromospheric activity produces both photometric and spectroscopic variations that can be mistaken as planets. Large spots crossing the stellar disc can produce planet-like periodic variations in the light curve of a star. These…

Solar and Stellar Astrophysics · Physics 2015-05-18 R. Martinez-Arnaiz , J. Maldonado , D. Montes , C. Eiroa , B. Montesinos

(Abridged) Understanding stellar activity in M dwarfs is crucial for the physics of stellar atmospheres as well as for ongoing radial velocity exoplanet programmes. Despite the increasing interest in M dwarfs, our knowledge of the…

We show that there is a relationship between the age excess, defined as the difference between the stellar isochrone and chromospheric ages, and the metallicity as measured by the index [Fe/H] for late-type dwarfs. The chromospheric age…

Astrophysics · Physics 2016-08-30 H. J. Rocha-Pinto , W. J. Maciel

We present high-resolution echelle spectroscopy of 676 nearby M dwarfs. Our measurements include radial velocities, equivalent widths of important chromospheric emission lines, and rotational velocities for rapidly rotating stars. We…

Astrophysics · Physics 2009-06-16 J. E. Gizis , I. N. Reid , S. L. Hawley

Monitoring chromospheric and photospheric indexes of magnetic activity can provide valuable information, especially the interaction between different parts of the atmosphere and their response to magnetic fields. We extract chromospheric…

Solar and Stellar Astrophysics · Physics 2020-02-25 Jinghua Zhang , Shaolan Bi , Yaguang Li , Jie Jiang , Tanda Li , Han He , Jie Yu , Shourya Khanna , Zhishuai Ge , Kang Liu , Zhijia Tian , Yaqian Wu , Xianfei Zhang

The variability of H$\alpha$ chromospheric activity of solar-like stars is investigated by using the time-domain data of LAMOST Medium-Resolution Spectroscopic Survey (MRS). We use $R_\mathrm{H\alpha}$ index (ratio of H$\alpha$ luminosity…

Solar and Stellar Astrophysics · Physics 2025-12-10 Han He , Ali Luo , Haotong Zhang , Song Wang

Aims. The Hyades cluster is key for the study of rotational, activity, and chemical evolution of solar-like low-mass stars. Here we present quantitative surface-activity information for a sequence of 21 Hyades dwarf stars. Conclusions. We…

Solar and Stellar Astrophysics · Physics 2025-11-26 K. G. Strassmeier , I. Ilyin , M. Steffen , S. A. Barnes

Stellar models with masses ranging from 0.5 to $1.3~M_\odot$ were constructed in order to compare to young cluster observations of Li and of rotation velocities. The amount of Li depletion in cool stars is sensitive to the amount of…

Astrophysics · Physics 2009-10-22 Brian Chaboyer , P. Demarque , M. H. Pinsonneault

High resolution echelle spectra of PW And (HD~1405) have been taken during eight observing runs from 1999 to 2002. The detailed analysis of the spectra allow us to determine its spectral type (K2V), mean heliocentric radial velocity (V_hel…

Astrophysics · Physics 2009-11-10 J. Lopez-Santiago , D. Montes , M. J. Fernandez-Figueroa , L. W. Ramsey

$\require{mediawiki-texvc}$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

We present chromospheric activity index $S\rm_{HK}$ measurements for over 13,000 F, G and K disk stars with high signal-to-noise ratio ($>$ 60) spectra in the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) spectroscopic sample. A…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. K. Zhao , T. D. Oswalt , G. Zhao , Q. H. Lu , A. L. Luo , L. Y. Zhang

By using the dense coverage of the extrasolar planet survey project HATNet, we Fourier analyze 381 high-probability members of the nearby open cluster Praesepe (Beehive/M44/NGC 2632). In addition to the detection of 10 variables (of \delta…

Most M dwarfs show higher chromospheric activity, often exceeding solar levels. Characterizing stellar activity is essential, particularly since these stars are prime targets in the search for habitable exoplanets. We investigate the…

Solar and Stellar Astrophysics · Physics 2026-01-14 A. S. Rajpurohit , V. Kumar , K. Srivastava Mudit , L. Labadie , K. Rajpurohit , J. G. Fernandez-Trincado

Stellar magnetic activity decays over the main-sequence life of cool stars due to the stellar spin-down driven by magnetic braking. The evolution of chromospheric emission is well-studied for younger stars, but difficulties in determining…

Solar and Stellar Astrophysics · Physics 2020-01-08 R S Booth , K. Poppenhaeger , C. A. Watson , V. Silva Aguirre , D. Stello , H. Bruntt

Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We…

Solar and Stellar Astrophysics · Physics 2016-12-14 D. Barrado , H. Bouy , J. Bouvier , E. Moraux , L. M. Sarro , E. Bertin , J. C. Cuillandre , J. R. Stauffer , J. Lillo-Box , A. Pollock

Stellar rotation periods measured in open clusters have proved to be extremely useful for studying stars' angular momentum content and rotationally driven magnetic activity, which are both age- and mass-dependent processes. While period…

Solar and Stellar Astrophysics · Physics 2016-05-25 Kevin R. Covey , Marcel A. Agüeros , Nicholas M. Law , Jiyu Liu , Aida Ahmadi , Russ Laher , David Levitan , Branimir Sesar , Jason Surace