228 datasets found

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...

Atomic transition probability measurements for 364 lines of Ti II in the UV through near-IR are reported. Branching fractions from data recorded using a Fourier transform...

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...

Solar and Heliospheric Observatory (SOHO) Extreme ultraviolet Imaging Telescope (EIT) data have been visually searched for coronal "EIT wave" transients over the period...

We have derived new abundances of the rare earth elements Pr, Dy, Tm, Yb, and Lu for the solar photosphere and for five very metal-poor, neutron-capture r-process-rich giant...

Solar photon scattering probabilities (g values) have been calculated for discrete transitions in 12 species, in a format designed primarily to allow analysis of spacecraft...

This paper presents semiempirical models of various solar magnetic structures, extending from the photosphere to the chromosphere. The models have been derived from non-LTE...

Determining the physical nature of a star requires precise knowledge of its stellar atmospheric parameters, including effective temperature, surface gravity, and metallicity....

We analyze periods with elevated >40MeV proton intensities observed near Earth over a time span of 43yr (1973-2016) that coincide with the passage of interplanetary (IP)...

The culmination of solar cycle 24 by the end of 2019 has created the opportunity to compare the differing properties of coronal mass ejections (CMEs) between two whole solar...

We report small-scale magnetic flux ropes via the in situ measurements from the Parker Solar Probe during the first six encounters, and present additional analyses to supplement...

State-of-the-art radial velocity (RV) exoplanet searches are limited by the effects of stellar magnetic activity. Magnetically active spots, plage, and network regions each have...

We model the Sun's large-scale magnetic field and total solar irradiance (TSI) since 1700 by combining flux transport simulations with empirical relationships between facular...

We analyze space-based time-series photometry of Sun-like stars, mostly in the Pleiades, but also field stars and the Sun itself. We focus on timescales between roughly 1hr and...

One of the key problems in solar flare physics is the determination of the low-energy cut-off: the value that determines the energy of nonthermal electrons and hence flare...

This statistical work studies the abundances and the charge states of the carbon, oxygen, and iron ions in 281 interplanetary coronal mass ejections (ICMEs) measured at 1 au by...

While the Sun is generally more eruptive during its maximum and declining phases, observational evidence shows certain cases of powerful solar eruptions during the quiet phase...

Interplanetary coronal mass ejections (ICMEs) could be classified into magnetic clouds (MCs) and non-MCs according to their magnetic field signatures, and into prominence-inside...