English
Related papers

Related papers: Two Practical Methods for Coronal Intensity Determ…

200 papers

Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar…

Solar and Stellar Astrophysics · Physics 2023-07-19 Paola Testa , Steve Saar , Jeremy Drake

Digital camera pixels measure image intensities by converting incident light energy into an analog electrical current, and then digitizing it into a fixed-width binary representation. This direct measurement method, while conceptually…

Computer Vision and Pattern Recognition · Computer Science 2021-04-13 Atul Ingle , Trevor Seets , Mauro Buttafava , Shantanu Gupta , Alberto Tosi , Mohit Gupta , Andreas Velten

The sky brightness is a critical parameter for estimating the coronal observation conditions for solar observatory. As part of a site-survey project in Western China, we measured the sky brightness continuously at the Lijiang Observatory in…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 M. Y. Zhao , Y. Liu , A. Elmhamdi , A. S. Kordi , X. F. Zhang , T. F. Song , Z. J. Tian

Comparing solar and stellar brightness variations is hampered by the difference in spectral passbands used in observations as well as by the possible difference in the inclination of their rotation axes from the line of sight. We calculate…

Solar and Stellar Astrophysics · Physics 2020-07-01 N. -E. Nèmec , E. Işık , A. I. Shapiro , S. K. Solanki , N. A. Krivova , Y. Unruh

We present an in-depth characterization of the polarimetric channel of the Large-Angle Spectrometric COronagraph LASCO-C2 onboard the Solar and Heliospheric Observatory (SoHO). The polarimetric analysis of the white-light images makes use…

Solar and Stellar Astrophysics · Physics 2020-07-21 Philippe Lamy , Antoine Llebaria , Brice Boclet , Hugo Gilardy , Michael Burtin , Olivier Floyd

The Crab nebula and its pulsar have been observed for about 3 hours with the high-speed photo-polarimeter OPTIMA in January 2002 at the Calar Alto 3.5m telescope. The Crab pulsar intensity and polarization are determined at all phases of…

Astrophysics · Physics 2009-01-14 G. Kanbach , A. Slowikowska , S. Kellner , H. Steinle

Angular broadening observations of compact radio sources provide a powerful method for probing the solar corona and solar wind. Such observations enable studies of the phase structure function, turbulence amplitude, intermediate-scale…

Understanding many physical processes in the solar atmosphere requires determination of the magnetic field in each atmospheric layer. However, direct measurements of the magnetic field in the Sun's corona are difficult to obtain. Using…

The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a…

Solar and Stellar Astrophysics · Physics 2019-03-20 C. D. Johnston , S. J. Bradshaw

We show that an intensity speckle can be directly interpreted as the properties of incident light - amplitude, phase, polarization, and coherency over spatial positions. Revisiting the speckle-correlation scattering matrix (SSM) method [Lee…

Optics · Physics 2019-08-07 KyeoReh Lee , YongKeun Park

Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations…

Solar and Stellar Astrophysics · Physics 2009-07-22 Harry P. Warren , David H. Brooks

We investigate the relationship between solar coronal holes and open-field regions using three-dimensional radiative magnetohydrodynamic (MHD) simulations combined with remote-sensing observations from the Solar Dynamics Observatory (SDO).…

Solar and Stellar Astrophysics · Physics 2025-10-31 Haruhisa Iijima

In the last decade, imaging polarimeters based on micropolarizer arrays have been developed for use in terrestrial remote sensing and metrology applications. Micropolarizer-based sensors are dramatically smaller and more mechanically robust…

Solar and Stellar Astrophysics · Physics 2020-02-11 Dmitry Vorobiev , Zoran Ninkov , Lee Bernard , Neal Brock

Extracting the temperature of coronal loops is effective in the analysis of solar active region's loops and helps in better understanding of coronal events. To this end, various methods have already been developed like the method developed…

Solar and Stellar Astrophysics · Physics 2019-08-30 Narges Fathalian

Some 8000 images obtained with the SECIS fast-frame CCD camera instrument located at Lusaka, Zambia, during the total eclipse of 21 June 2001 have been analyzed to search for short-period oscillations in intensity that could be a signature…

Solar and Stellar Astrophysics · Physics 2015-05-20 P. Rudawy , K. J. H. Phillips , A. Buczylko , D. R. Williams , F. P. Keenan

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

The Wide-field Imager for Parker Solar Probe (WISPR) captures unprecedented white-light images of the solar corona and inner heliosphere. Thanks to the uniqueness of Parker Solar Probe's (PSP) orbit, WISPR is able to image ``locally''…

Data obtained in the framework of the INTERBALL-Tail Probe (1995-2000) and RHESSI (from 2002 to the present) projects have revealed variations in the X-ray intensity of the solar corona in the photon energy range of 2-15 keV during the…

High Energy Astrophysical Phenomena · Physics 2019-04-08 I. K. Mirzoeva , S. G. Chefranov

We aim to study excitation of the observed 5-min oscillations in the solar corona by localized pulses that are launched in the photosphere. We solve the full set of nonlinear one-dimensional Euler equations numerically for the velocity…

Solar and Stellar Astrophysics · Physics 2015-05-27 T. V. Zaqarashvili , K. Murawski , M. K. Khodachenko , D. Lee

Given its unchallenged capabilities in terms of sensitivity and spatial resolution, the combination of imaging spectropolarimetry and numeric Stokes inversion represents the dominant technique currently used to remotely sense the physical…

Instrumentation and Methods for Astrophysics · Physics 2019-11-05 Francisco A. Iglesias , Alex Feller