English
Related papers

Related papers: Two Practical Methods for Coronal Intensity Determ…

200 papers

Coronal bright points (CBPs) as characteristics of the solar corona are small-scale bright features ubiquitously observed at extreme ultraviolet passbands. Here, we focused on time series of CBPs in the periods of their lifetimes. We used…

Solar and Stellar Astrophysics · Physics 2019-01-25 Mahdieh Mehrabian , Bardia Kaki , Yusefali Abedini

The global structure of solar corona observed in optical window is governed by the global magnetic field with different characteristics over solar activity cycle. Ludendorff flattening index becomes a popular measure of the global structure…

Solar and Stellar Astrophysics · Physics 2016-12-14 Rhorom Priyatikanto

The spatial-temporal evolution of coronal plasma parameters of the solar outer atmosphere at global scales, derived from solar full-disk imaging spectroscopic observation in the extreme-ultraviolet band, is critical for understanding and…

Solar and Stellar Astrophysics · Physics 2024-10-23 Yufei Feng , Xianyong Bai , Sifan Guo , Hui Tian , Lami Chan , Yuanyong Deng , Qi Yang , Wei Duan , Xiaoming Zhu , Xiao Yang , Zhiwei Feng , Zhiyong Zhang

The angular broadening of compact radio sources observed through a medium having turbulent density irregularities is usually estimated using the phase structure function. We employ an exact formulation for the phase structure function that…

Solar and Stellar Astrophysics · Physics 2014-06-23 Madhusudan Ingale , Prasad Subramanian , Iver H. Cairns

The apparent brightness of satellites is calculated as a function of satellite position as seen by a ground-based observer in darkness. Both direct illumination of the satellite by the Sun as well as indirect illumination due to reflection…

Instrumentation and Methods for Astrophysics · Physics 2023-10-13 Forrest Fankhauser , J. Anthony Tyson , Jacob Askari

The solar corona is a highly-structured plasma which can reach temperatures of more than ~2 MK. At low frequencies (decimetric and metric wavelengths), scattering and refraction of electromagnetic waves are thought to considerably increase…

We report a detailed analysis of the coronal abundance of 4 stars with varying levels of activity and with accurately known photospheric abundances. The coronal abundance is determined here using a line flux analysis and a full…

Astrophysics · Physics 2009-11-10 J. Sanz-Forcada , F. Favata , G. Micela

Context. The corona of the Sun is the part of the solar atmosphere with temperatures of over one million Kelvin, which needs to be heated internally in order to exist. This heating mechanism remains a mystery; we see large magnetically…

Solar and Stellar Astrophysics · Physics 2023-11-03 I. Kraus , Ph. -A. Bourdin , J. Zender , M. Bergmann , A. Hanslmeier

One of the most important objectives of solar physics is the physical understanding of the solar atmosphere, the structure of which is also described in terms of the density (N) and temperature (T) distributions of the atmospheric matter.…

X-Ray and Ultraviolet (UV) observations of the outer solar atmosphere have been used for many decades to measure the fundamental parameters of the solar plasma. This review focuses on the optically thin emission from the solar atmosphere,…

Solar and Stellar Astrophysics · Physics 2018-09-06 Giulio Del Zanna , Helen E. Mason

Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these…

Solar and Stellar Astrophysics · Physics 2015-05-13 K. Wilhelm , B. N. Dwivedi , W. Curdt

We propose and test a wavelet transform modulus maxima method for the au- tomated detection and extraction of coronal loops in extreme ultraviolet images of the solar corona. This method decomposes an image into a number of size scales and…

Solar and Stellar Astrophysics · Physics 2010-02-17 R. T. James McAteer , Pierre Kestener , Alain Arneodo , Andre Khalil

Extreme UltraViolet images of the corona contain information over a large range of spatial scales, and different structures such as active regions, quiet Sun and filament channels contain information at very different brightness regimes.…

Solar and Stellar Astrophysics · Physics 2015-06-19 Huw Morgan , Miloslav Druckmuller

Absorption imaging of ultracold atoms is the foundation for quantitative extraction of information from experiments with ultracold atoms. Due to the limited exposure time available in these systems, the signal-to-noise ratio is largest for…

We present a new methodology -- the Keplerian Optical Dynamics Analysis (KODA) -- for analyzing the dynamics of dense, cool material in the solar corona. The technique involves adaptive spatiotemporal tracking of propagating intensity…

Solar and Stellar Astrophysics · Physics 2022-08-24 V. M. Uritsky , B. J. Thompson , C. R. DeVore

The X-ray emission from the Sun reveals a very dynamic hot atmosphere, the corona, which is characterized by a complex morphology and broad range of timescales of variability and spatial structuring. The solar magnetic fields play a…

Solar and Stellar Astrophysics · Physics 2022-06-09 Paola Testa , Fabio Reale

It is argued that depolarization of solar radio bursts requires reflection off boundary layers no thicker than about a wavelength (a few meters at most) between regions with large density ratios. The implied inhomogeneities suggest that the…

Astrophysics · Physics 2009-11-13 D. B Melrose

The quiescent or dynamic nature of fine scale ray-like features in the sun corona, observed in visible light, is still an open question. Here, we show that most of daily and hourly periodic variations in visible light brightness of the high…

Solar and Stellar Astrophysics · Physics 2025-09-16 Nathalia Alzate , Simone Di Matteo

Full-disk spectroscopic observations of the solar corona are highly desired to forecast solar eruptions and their impact on planets and to uncover the origin of solar wind. In this paper, we introduce a new multi-slit design (5 slits) to…

Solar and Stellar Astrophysics · Physics 2024-06-12 Lami Chan , Hui Tian , Xianyu Liu , Tibor Török , Xianyong Bai , Yufei Feng , Dipankar Banerjee

Comparison of appropriate theoretical derived line ratios with observational data can yield estimates of a plasma's physical parameters, such as electron density or temperature. The usual practice in the calculation of the line ratio is the…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. G. Doyle , S. Chapman , P. Bryans , D. Perez-Suarez , A. Singh , H. Summers , D. W. Savin
‹ Prev 1 3 4 5 6 7 10 Next ›