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Related papers: Sun-like Stars Shed Light on Solar Climate Forcing

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Solar X-ray and UV radiation (0.1-320 nm) received at Earth's surface is an important aspect of the circumstances under which life formed on Earth. The quantity that is received depends on two main variables: the emission of radiation by…

Astrophysics · Physics 2008-11-26 I. Cnossen , J. Sanz-Forcada , F. Favata , O. Witasse , T. Zegers , N. F. Arnold

The rich absorption spectra of Sun-like stars are enticing probes for variations in the fine-structure constant, $\alpha$, which gauges the strength of electromagnetism. While individual line wavelengths are sensitive to $\alpha$, they are…

Solar and Stellar Astrophysics · Physics 2023-01-04 Daniel A. Berke , Michael T. Murphy , Chris Flynn , Fan Liu

We analyze 15 years of Fermi-LAT data and produce a detailed model of the Sun's inverse-Compton scattering emission (solar halo), which is powered by interactions between ambient cosmic-ray electrons and positrons with sunlight. By…

High Energy Astrophysical Phenomena · Physics 2026-01-28 Tim Linden , Jung-Tsung Li , Bei Zhou , Isabelle John , Milena Crnogorčević , Annika H. G. Peter , John F. Beacom

This work provides additional evidence on the involvement of exotic particles like axions and/or other WISPs, following recent measurements during the quietest Sun and flaring Sun. Thus, SPHINX mission observed a minimum basal soft X-rays…

Solar and Stellar Astrophysics · Physics 2011-12-20 K. Zioutas , M. Tsagri , Y. Semertzidis , T. Papaevangelou , E. Georgiopoulou , A. Gardikiotis , T. Dafni

Searching the literature, we found 25 stars with directly imaged planets and candidates. We gathered photometric and spectral information for all these objects to derive their luminosities in a homogeneous way, taking a bolometric…

Earth and Planetary Astrophysics · Physics 2012-01-18 R. Neuhäuser , T. O. B. Schmidt

The $\gamma$-ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a stellar disk emission, where $\gamma$-rays are mainly…

High Energy Astrophysical Phenomena · Physics 2021-08-04 Raniere de Menezes , Elena Orlando , Mattia Di Mauro , Andrew Strong

The NASA Kepler mission is providing an unprecedented set of asteroseismic data. In particular, short-cadence lightcurves (~60s samplings), allow us to study solar-like stars covering a wide range of masses, spectral types and evolutionary…

The objective reality of the Earth's motion about the Sun was finally proven observationally by Bradley (1727) when he correctly explained the ~20'' annual, elliptical motions of stars as being due to aberration of starlight caused by the…

Earth and Planetary Astrophysics · Physics 2018-09-05 Jason T. Wright

The reconstruction and prediction of solar activity is one of the current problems in dynamo theory and global climate modeling. We estimate the Total Solar Irradiance for the next hundred years based on the Least Square Support Vector…

Solar and Stellar Astrophysics · Physics 2011-11-14 Victor Manuel Velasco Herrera , Blanca Mendoza , Graciela Velasco Herrera

We report on an ongoing investigation into a seismic calibration of solar models designed for estimating the main-sequence age and a measure of the chemical abundances of the Sun. Only modes of low degree are employed, so that with…

Astrophysics · Physics 2009-11-13 G. Houdek , D. O. Gough

Age determination is undertaken for nearby early-type (BAF) stars, which constitute attractive targets for high-contrast debris disk and planet imaging surveys. Our analysis sequence consists of: acquisition of uvby{\beta} photometry from…

Solar and Stellar Astrophysics · Physics 2015-05-18 Trevor J. David , Lynne A. Hillenbrand

Aims: The aim of this paper is to demonstrate that millimeter wave data can be used to distinguish between various atmospheric models of sunspots, whose temperature structure in the upper photosphere and chromosphere has been the source of…

Solar and Stellar Astrophysics · Physics 2015-01-14 Maria A. Loukitcheva , Sami K. Solanki , Stephen M. White

At radio wavelengths, solar-type stars emit thermal free-free and gyroresonance, gyrosynchrotron, and impulsive coherent emission. Thermal free-free emission originates at layers where the optical depth is close to unit, while high…

Solar and Stellar Astrophysics · Physics 2018-08-29 C. Trigilio , G. Umana , F. Cavallaro , C. Agliozzo , P. Leto , C. S. Buemi , A. Ingallinera , F. Bufano , S. Riggi

Context. There is no consensus on the amplitude of the historical solar forcing. The estimated magnitude of the total solar irradiance difference between Maunder minimum and present time ranges from 0.1 to 6 W/m2 making uncertain the…

Solar and Stellar Astrophysics · Physics 2018-07-18 T. Egorova , W. Schmutz , E. Rozanov , A. I. Shapiro , I. Usoskin , J. Beer , R. V. Tagirov , T. Peter

The Sun is used as the fundamental standard in chemical abundance studies, thus it is important to know whether the solar abundance pattern is representative of the solar neighborhood. Albeit at low precision (0.05 - 0.10 dex) the Sun seems…

Solar and Stellar Astrophysics · Physics 2015-06-16 Jorge Melendez

We have been using a new method to search for solar-like oscillations that involves measuring temperature changes via their effect on the equivalent widths of the Balmer hydrogen lines. We observed alpha Cen A over six nights in 1995 with…

Astrophysics · Physics 2007-05-23 Timothy R. Bedding , Hans Kjeldsen , S. Frandsen , T. H. Dall

Solar twins and analogs are fundamental in the characterization of the Sun's place in the context of stellar measurements, as they are in understanding how typical the solar properties are in its neighborhood. They are also important for…

Solar and Stellar Astrophysics · Physics 2015-06-18 G. F. Porto de Mello , R. da Silva , L. da Silva , R. V. de Nader

This article presents a power-spectrum analysis of 39,024 measurements of the solar diameter made at the Mount Wilson Observatory from 1968.670 to 1997.965. This power spectrum contains a number of very strong peaks. We find that eight of…

Solar and Stellar Astrophysics · Physics 2015-05-20 Peter A. Sturrock , Luca Bertello

A list of 4,131 dwarfs, subgiants, and giants located, or suspected to be located, within 33 parsecs of the Sun is presented. All the stars are drawn from the new LSPM-north catalog of 61,976 stars with annual proper motions larger than…

Astrophysics · Physics 2008-11-26 Sebastien Lepine

The Earth's albedo is a fundamental climate parameter for understanding the radiation budget of the atmosphere. It has been traditionally measured from space platforms, but also from the ground for sixteen years from Big Bear Solar…