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Related papers: The nature of solar brightness variations

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Solar contamination, due to moonlight and atmospheric scattering of sunlight, can cause systematic errors in stellar radial velocity (RV) measurements that significantly detract from the ~10cm/s sensitivity required for the detection and…

Frequency separations used to infer global properties of stars through asteroseismology can change depending on the strength and at what epoch of the stellar cycle the p-mode frequencies are measured. In the Sun these variations have been…

Solar and Stellar Astrophysics · Physics 2015-05-20 O. L. Creevey , D. Salabert , R. A. Garcia

Solar irradiance is considered one of the main natural factors affecting terrestrial climate, and its variations are included in most numerical models estimating the effects of natural versus anthropogenic factors for climate change. Solar…

Solar and Stellar Astrophysics · Physics 2014-11-25 Katya Georgieva , Yury Nagovitsyn , Boian Kirov

The Sun is a variable star whose magnetic activity varies most perceptibly on a timescale of approximately 11 years. However, significant variation is also observed on much shorter timescales. We observe a quasi-biennial (2 year) signal in…

Context. In time-distance helioseismology, wave travel times are measured from the two-point cross-covariance function of solar oscillations and are used to image the solar convection zone in three dimensions. There is, however, also…

Solar and Stellar Astrophysics · Physics 2017-03-08 Kaori Nagashima , Damien Fournier , Aaron C. Birch , Laurent Gizon

The light curves of solar-type stars present both periodic fluctuation and flare spikes. The gradual periodic fluctuation is interpreted as the rotational modulation of magnetic features on the stellar surface and is used to deduce magnetic…

Solar and Stellar Astrophysics · Physics 2018-05-15 Han He , Huaning Wang , Mei Zhang , Ahmad Mehrabi , Yan Yan , Duo Yun

We use Renewal Theory for the estimation and interpretation of the flare rate from the Geostationary Operational Environmental Satellite (GOES) soft X-ray flare catalogue. It is found, that in addition to the flare rate variability with the…

Solar and Stellar Astrophysics · Physics 2015-03-20 Andrei Gorobets , Mauro Messerotti

Small cyclic variations in the frequencies of acoustic modes are expected to be a common phenomenon in solar-like pulsators, as a result of stellar magnetic activity cycles. The frequency variations observed throughout the solar and stellar…

Solar and Stellar Astrophysics · Physics 2015-06-12 A. R. G. Santos , M. S. Cunha , J. J. G. Lima

On 12 March 1996 we obtained observations of the quiet Sun with the SUMER instrument. The observa- tions were sequences of 15-20 second exposures of ultraviolet emission line profiles and of the neighboring continua. These data contain…

Astrophysics · Physics 2009-10-30 Mats Carlsson , Philip G. Judge , Klaus Wilhelm

We determine here peculiar motion of the Solar system, first time from the $m-z$ Hubble diagram of quasars. Observer's peculiar motion causes a systematic shift in the $m-z$ plane between sources lying along the velocity vector and those in…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-14 Ashok K. Singal

Context. The Sun's complex corona is the source of the solar wind and interplanetary magnetic field. While the large scale morphology is well understood, the impact of variations in coronal properties on the scale of a few degrees on…

We reassess the claimed detection of variability in the atmosphere of the hot Jupiter HAT-P-7 b, reported by Armstrong et al. (2016). Although astronomers expect hot Jupiters to have changing atmospheres, variability is challenging to…

Earth and Planetary Astrophysics · Physics 2022-03-30 Maura Lally , Andrew Vanderburg

The high-quality, full-disk helioseismic observations continuously collected by the spectrophotometer GOLF and the three photometers VIRGO/SPMs onboard the SoHO spacecraft for 17 years now (since April 11, 1996, apart from the SoHO…

Solar and Stellar Astrophysics · Physics 2013-09-18 D. Salabert , R. A. Garcia , A. Jimenez

Fluctuations in the flow velocity and magnetic fields are ubiquitous in the Solar System. These fluctuations are turbulent, in the sense that they are disordered and span a broad range of scales in both space and time. The study of solar…

Solar and Stellar Astrophysics · Physics 2016-02-04 F. Fraternale , L. Gallana , M. Iovieno , M. Opher , J. D. Richardson , D. Tordella

Co-rotating spots at different latitudes on the stellar surface generate periodic photometric variability and can be useful proxies to detect Differential Rotation (DR). DR is a major ingredient of the solar dynamo but observations of…

Solar and Stellar Astrophysics · Physics 2015-06-16 Timo Reinhold , Ansgar Reiners

While it is possible to estimate the dark matter density at the Sun distance from the galactic center, this does not give information on actual dark matter density in the Solar system. There can be considerable local enhancement of dark…

High Energy Physics - Phenomenology · Physics 2024-08-21 Dmitry Budker , Joshua Eby , Marianna S. Safronova , Oleg Tretiak

The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed…

Solar and Stellar Astrophysics · Physics 2016-03-09 Robert Sych

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 exhibits episodic surges of magnetic activity across a range of temporal and spatial scales, the most prominent of which is the 11-ish year modulation of sunspot production. Beside the ~170 (min to max) decadal variation in sunspot…

Solar and Stellar Astrophysics · Physics 2024-08-21 Scott W. McIntosh , Robert J. Leamon

Recently discovered long-term oscillations of the solar background magnetic field associated with double dynamo waves generated in inner and outer layers of the Sun indicate that the solar activity is heading in the next three decades…

Solar and Stellar Astrophysics · Physics 2020-04-13 V. V. Zharkova , S. J. Shepherd , E. Popova
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