Irradiance Variations of the Sun and Sun-Like Stars – Overview of Topical Collection

Kopp, Greg; Шапиро, А. И.

doi:10.1007/s11207-021-01802-8

Cited by 15 publications

(10 citation statements)

References 105 publications

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“…The magnetic fields emerging on solar and stellar surfaces lead to the formation of surface magnetic features, such as dark spots and bright faculae (see, e.g., Solanki et al 2006, for a review of the solar case). An exciting manifestation of these magnetic features is the temporal variation of brightness of the Sun and solar-like stars (Solanki et al 2013;Ermolli et al 2013;Kopp & Shapiro 2021).…”

Section: Introductionmentioning

confidence: 99%

Faculae Cancel out on the Surfaces of Active Suns

Nèmec

Шапиро

Işık

et al. 2022

ApJL

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Surfaces of the Sun and other cool stars are filled with magnetic fields, which are either seen as dark compact spots or more diffuse bright structures like faculae. Both hamper detection and characterization of exoplanets, affecting stellar brightness and spectra, as well as transmission spectra. However, the expected facular and spot signals in stellar data are quite different, for instance, they have distinct temporal and spectral profiles. Consequently, corrections of stellar data for magnetic activity can greatly benefit from the insight on whether the stellar signal is dominated by spots or faculae. Here, we utilize a surface flux transport model to show that more effective cancellation of diffuse magnetic flux associated with faculae leads to spot area coverages increasing faster with stellar magnetic activity than that by faculae. Our calculations explain the observed dependence between solar spot and facular area coverages and allow its extension to stars that are more active than the Sun. This extension enables anticipating the properties of stellar signal and its more reliable mitigation, leading to a more accurate characterization of exoplanets and their atmospheres.

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Section: Introductionmentioning

confidence: 99%

Faculae Cancel out on the Surfaces of Active Suns

Nèmec

Шапиро

Işık

et al. 2022

ApJL

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“…2002; monthly data). TSI is a common and useful proxy for estimating the SA evolution over long time scales, which corresponds to the spatially and spectrally integrated radiative output of the Sun incident at the top of the Earth’s atmosphere (and normalized to a distance of one astronomical unit, 1 AU, from the Sun; Kopp & Shapiro 2021), whereas the NAO is an atmospheric mode that controls a large amount of the winter European climate variability (Deser et al . 2017).…”

Section: Methodsmentioning

confidence: 99%

Examining the role of solar activity, climate, and the socio‐historical context in high all‐cause mortality (northern Portugal, 1700–1880)

Moreno¹,

Moreno

Fatela

et al. 2021

Boreas

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The far‐reaching impact of the Sun on Earth's climate and on people's health and well‐being is a poorly understood and non‐consensual scientific issue, with empirical literature stressing the need to expand the knowledge of such relationships. Here, the interplay between solar activity (SA) and climate, and its likely cascading effects on all‐cause mortality, were examined at several time scales. To this end, the parish records of Braga (1700–1880) and Torre de Moncorvo (1700–1850), in two different geographical locations of northern Portugal (Iberia, SW Europe), were used. Crude mortality rate (CMR) and winter–summer ratio (W/S) values were computed to characterize mortality patterns/trends and couple them with potential relevant drivers: total solar irradiance (TSI) as a proxy of SA, the North Atlantic Oscillation (NAO), and key historical events. What emerged, albeit incomplete, was a complex picture of death deeply embedded in people’s physical and socioeconomic environments, at a time when ubiquitous poverty (and co‐morbid malnutrition) was the most inveterate cause of ill health. After identifying the positive mortality episodes in both municipalities, their incidence was found to be higher in periods of weakened SA (normal/grand minima). Standard inference statistics were used to estimate the significance of the observations. The highest CMR peaks matched not only with wars but also with known wide‐ranging mortality crises, which seem to have been triggered by major agricultural production shortfalls, followed by substantial increases in food prices, driven, in turn, by climate deterioration, including extreme weather occurrences. The outcome was social unrest, famines, and outbreaks of infectious diseases, heightening the death toll. The influence of prominent solar/climate variations was investigated using wavelet transform coherence analysis (WTC). The results showed (multi)decadal oscillations in both (TSI and NAO) somehow regulating mortality. But the WTC analysis also estimated SA signals in low‐frequency mortality dynamics disguised by time‐varying determinants, where distinct players of space weather might have been implicated.

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“…relacionados com a radiação solar e seus impactos na Terra. O monitoramento da TSI, como por exemplo do SORCE/TIM 2 , apresentado por Kopp [33], mostra variações correlacionadas com o ciclo de atividade solar.…”

Section: Radiac ¸ãO Estelarunclassified

Aspectos do Sol observados em diferentes faixas espectrais

Almeida

Gregorio-Hetem

2022

Rev. Bras. Ensino Fís.

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A busca por novas metodologias e estratégias para transformar as aulas de Física mais próximas da realidade dos(as) estudantes do Ensino Médio, faz com que professores(as) criem novas atividades com ideias diferentes das que são usualmente apresentadas em livros didáticos. Nesse contexto, utilizou-se o Sol como base conhecida para explicar os conceitos de ondas eletromagnéticas e radiação de corpo negro, abordando esse conteúdo por meio da Função de Planck, da Lei de Wien e da Lei de Stefan-Boltzmann de uma forma aplicada, com o uso de um programa desenvolvido para esse fim, e de imagens astronômicas obtidas com tecnologia de ponta, visando tornar o aprendizado mais significativo. O objetivo é apresentar a possibilidade do uso de informações relativas ao Sol como tema norteador para o aprendizado dos conteúdos de Física Moderna, motivando os(as) estudantes durante o processo educativo. Além disso, apresenta-se um resumo dos conceitos básicos relacionados ao Sol, buscando levar aos(às) professores(as) uma forma de compreender os processos físicos que explicam as diferentes características solares observadas em faixas espectrais específicas.

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Irradiance Variations of the Sun and Sun-Like Stars – Overview of Topical Collection

Cited by 15 publications

References 105 publications

Faculae Cancel out on the Surfaces of Active Suns

Faculae Cancel out on the Surfaces of Active Suns

Examining the role of solar activity, climate, and the socio‐historical context in high all‐cause mortality (northern Portugal, 1700–1880)

Aspectos do Sol observados em diferentes faixas espectrais

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