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The solar group at the National Astronomical Observatory of Japan is conducting synoptic solar observations with the Solar Flare Telescope. While it is a part of a long-term solar monitoring, contributing to the study of solar dynamo…

Solar and Stellar Astrophysics · Physics 2020-09-29 Yoichiro Hanaoka , Takashi Sakurai , Ken'ichi Otsuji , Isao Suzuki , Satoshi Morita

Waves have long been thought to contribute to the heating of the solar corona and the generation of the solar wind. Recent observations have demonstrated evidence of quasi-periodic longitudinal disturbances and ubiquitous transverse wave…

Solar and Stellar Astrophysics · Physics 2015-06-16 J. Threlfall , I. De Moortel , S. W. McIntosh , C. Bethge

We present a method for measuring the Sun's motion using the proper motions of Galactic halo star streams. The method relies on the fact that the motion of the stars perpendicular to a stream from a low-mass progenitor is close to zero when…

Astrophysics of Galaxies · Physics 2017-08-16 Khyati Malhan , Rodrigo A. Ibata

The Space Infrared Telescope Facility (SIRTF) will drift away from the Earth at about 0.1 AU/yr. Microlensing events will therefore have different characteristics as seen from the satellite and the Earth. From the difference, it is possible…

Astrophysics · Physics 2009-10-30 Andrew Gould

The Sun shows a wide range of temporal variations, from a few seconds to decades and even centuries, broadly classified into two classes short-term and Long-term. The solar dynamo mechanism is believed to be responsible for these global…

Solar and Stellar Astrophysics · Physics 2023-02-21 Bibhuti Kumar Jha

Clouds cast shadows on the surface and locally enhance solar irradiance by absorbing and scattering sunlight, resulting in fast and large solar irradiance fluctuations on the surface. Typical spatiotemporal scales and driving mechanisms of…

Atmospheric and Oceanic Physics · Physics 2023-03-09 Wouter Mol , Bart van Stratum , Wouter Knap , Chiel van Heerwaarden

Direct Sun light absorption by trace gases can be used to quantify them and investigate atmospheric chemistry. In such experiments, the main optical apparatus is often a grating or a Fourier transform spectrometer. A solar tracker based on…

We investigate the effects of atmospheric dispersion on observations of the Sun at the ever-higher spatial resolutions afforded by increased apertures and improved techniques. The problems induced by atmospheric refraction are particularly…

Astrophysics · Physics 2008-11-26 Kevin P. Reardon

As the Universe expands, the redshift of distant sources changes with time. Here we discuss gravitational lensing phenomena that are consequence of the redshift drift between lensed source, gravitational lens, and observer. When the source…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Giovanni Covone , Mauro Sereno

Drift-diffusion theory - which fully describes charge transport in semiconductors - is also universally used to model transport of spin-polarized electrons in the presence of longitudinal electric fields. By transforming spin transit time…

Materials Science · Physics 2010-12-21 Biqin Huang , Ian Appelbaum

At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…

Solar and Stellar Astrophysics · Physics 2024-09-06 Laura Jade Millson , Anne-Marie Broomhall , Tishtrya Mehta

For human pose estimation in videos, it is significant how to use temporal information between frames. In this paper, we propose temporal flow maps for limbs (TML) and a multi-stride method to estimate and track human poses. The proposed…

Computer Vision and Pattern Recognition · Computer Science 2019-05-24 Jihye Hwang , Jieun Lee , Sungheon Park , Nojun Kwak

Context: Stellar flares have an impact on habitable planets. To relate the observations of the Sun with those of stars, one needs to use a Sun-as-a-star analysis, that is, to degrade the resolution of the Sun to a single point. With the…

Solar and Stellar Astrophysics · Physics 2025-02-04 H. C. Yu , J. Hong , M. D. Ding

Starspots are cooler and darker than the stellar surface. Therefore, the emitted flux of a star changes when spots are visible on its surface. The presence of spots together with the stellar rotation leads to a periodic modulation on the…

Solar and Stellar Astrophysics · Physics 2017-11-08 A. R. G. Santos , M. S. Cunha , P. P. Avelino , R. A. García , S. Mathur

We present results from fitting $p$-mode spectra derived from 7-d segments of Sun-as-a-star helioseismic observations from the Birmingham Solar Oscillations Network covering 32 yr. The results show a clear dependence of the mode frequencies…

Solar and Stellar Astrophysics · Physics 2025-01-15 R. Howe , W. J. Chaplin , Y. P. Elsworth , S. J. Hale , E. Hatt , M. B. Nielsen

Looming, traditionally defined as the relative expansion of objects in the observer's retina, is a fundamental visual cue for perception of threat and can be used to accomplish collision free navigation. The measurement of the looming cue…

Computer Vision and Pattern Recognition · Computer Science 2022-03-16 Juan D. Yepes , Daniel Raviv

The latitudinal location of the sunspot zones in each hemisphere is determined by calculating the centroid position of sunspot areas for each solar rotation from May 1874 to June 2011. When these centroid positions are plotted and analyzed…

Solar and Stellar Astrophysics · Physics 2015-05-30 D. H. Hathaway

One of the main uncertainties associated with time-distance measurements is how to interpret observations made in regions of strong magnetic field as isolating the effects of the magnetic field from thermal or sound-speed perturbations has…

Astrophysics · Physics 2009-11-13 H. Moradi , P. S. Cally

In this paper Fourier Transform and Wavelet Transform are applied in case of recent 300 years of sunspot numbers to explain the solar cycles. Here basically parallel study of Fourier and Wavelet analysis are done and we have observed that…

Computational Engineering, Finance, and Science · Computer Science 2013-12-11 Sabyasachi Mukhopadhyay , Debadatta Dash , Asish Mitra , Prasanta K. Panigrahi

Precise photometry from the Kepler space telescope allows not only the measurement of rotation in solar-type field stars, but also the determination of reliable masses and ages from asteroseismology. These critical data have recently…

Solar and Stellar Astrophysics · Physics 2016-08-29 Travis S. Metcalfe , Ricky Egeland , Jennifer van Saders
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