198 datasets found

Angelo Secchi, an Italian Jesuit and prominent scientist of the 19th century, and one of the founders of modern astrophysics, observed the Sun regularly at the Collegio Romano...

Solar Eclipses - During the twenty-five year period 1996-2020, some portion of the Moon's shadow will sweep across the Earth a total of fifty-six times. Twenty-one of these...

The accurate measurement of the solar spectrum at the top of the atmosphere and its variability are fundamental inputs for solar physics (Sun modeling), terrestrial atmospheric...

Coronal holes are usually defined as dark structures seen in the extreme ultraviolet and X-ray spectrum which are generally associated with open magnetic fields. Deriving...

Accurate measurements of the solar spectral irradiance (SSI) and its temporal variations are of primary interest to better understand solar mechanisms, and the links between...

In this work, we present digital and graphical atlases of spectra of both the solar disk-center and of the limb near the Solar poles using data taken at the UTS-IAP & RIAAM...

Radiative atomic and electron impact excitation data for OV and OVI ions have been calculated. The radiative atomic data have been calculated with the AUTOSTRUCTURE code....

An analysis of the chemical composition of the solar atmosphere is performed using spectrograms of the daylight sky obtained on the ZTS telescope (dispersion 3{AA}/mm,...

The Wilson-Bappu effect (WBE) is a remarkable correlation between the width of the chromospheric emission core of the CaII 3934{AA} K line and stellar absolute visual magnitude...

Using ion measurements from Ultra-Low-Energy Isotope Spectrometer observations on board Advanced Composition Explorer and Solar Isotope Spectrometer observations on board the...

A sunspot observation program was started at the end of the 19th century at the Stonyhurst College Observatory (hereafter SCO) by Father Perry, director of the observatory at...

We present the first Fermi Large Area Telescope (LAT) catalog of long-term {gamma}-ray transient sources (1FLT). This comprises sources that were detected on monthly time...

We derived high-precision reference profiles of the MgII h and k lines that represent the quiet Sun during a minimum of the solar activity. To do so, we used the broad catalog...

The Lyman-alpha (Ly{alpha}) line of neutral hydrogen at 121.6nm is by far the brightest emission line in the vacuum ultraviolet spectral range of the Sun. The emission at this...

In our companion papers (Hollick+ 2018ApJ...863...75H and 2018ApJ...863...76H) we analyze 637 intervals of magnetic wave activity observed by the Voyager 1 and 2 spacecraft from...

We use a three-dimensional magnetohydrodynamic simulation of the solar wind to calculate cosmic-ray diffusion coefficients throughout the inner heliosphere (2R_{sun}_-3au). The...

The OPAS opacity model has been used to calculate the radiative opacity of stellar plasmas in local thermodynamic equilibrium. According to the recent chemical composition...

New emission branching fraction measurements for 836 lines of the first spectrum of vanadium (VI) are determined from hollow cathode lamp spectra recorded with the National...

We investigate the absolute calibration of the EUV Imaging Spectrometer (EIS) on Hinode by comparing EIS full-disk mosaics with irradiance observations from the EUV Variability...

Atomic transition probability measurements for 371 NiI lines in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform...