Related papers: Universal Scaling Laws for Solar and Stellar Atmos…
We present EUV solar observations showing evidence for omnipresent jetting activity driven by small-scale magnetic reconnection at the base of the solar corona. We argue that the physical mechanism that heats and drives the solar wind at…
Despite their importance for determining the evolution of the Earth's atmosphere and surface conditions, the evolutionary histories of the Earth's atmospheric CO$_2$ abundance during the Archean eon and the Sun's activity are poorly…
Condensations in the more than 10^6 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide…
Extremely irradiated, close-in planets to early-type stars might be prone to strong atmospheric escape. We review the literature showing that X-ray-to-optical measurements indicate that for intermediate-mass stars (IMS) cooler than…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
We are investigating the possible origin of small-scale anomalies, like the annual stratospheric temperature anomalies. Unexpectedly within known physics, their observed planetary "dependency", does not match concurrent solar activity,…
Coronal mass ejections (CMEs) are often associated with X-ray (SXR) flares powered by magnetic reconnection in the low-corona, while the CME shocks in the upper corona and interplanetary (IP) space accelerate electrons often producing the…
The Sun is a standard reference object for Astrophysics and also a fascinating subject of study in its own right. X-ray and extreme ultraviolet movies of the Sun's atmosphere show an extraordinary diversity of plasma phenomena, from barely…
The magnetic field of the Sun drives a wide range of eruptive phenomena, from small-scale nanoflares to large flares and coronal mass ejections (CMEs). While direct observations of solar activity cover only the past few decades, indirect…
The existence of the million-degree corona above the cooler photosphere is an unsolved problem in astrophysics. Detailed study of quiescent corona that exists regardless of the phase of the solar cycle may provide fruitful hints towards…
Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…
Space weather in exoplanetary systems, driven by transient stellar emissions such as flares, coronal mass ejections, and stellar proton events, can significantly influence planetary habitability and the long-term evolution of atmospheres.…
Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned…
We report on the results of the Sun in Time multi-wavelength program (X-rays to the UV) of solar analogs with ages covering ~0.1-7 Gyr. The chief science goals are to study the solar magnetic dynamo and to determine the radiative and…
Spectroscopic observations at extreme and far ultraviolet wavelengths have revealed systematic upflows in the solar transition region and corona. These upflows are best seen in the network structures of the quiet Sun and coronal holes,…
X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars,…
Aims: We investigate the atmospheric response to coronal heating driven by random flows with different characteristic time scales and amplitudes. Methods: We conducted a series of 3D MHD simulations of random driving imposed on a…
The basic mechanisms responsible for producing winds from cool, late-type stars are still largely unknown. We take inspiration from recent progress in understanding solar wind acceleration to develop a physically motivated model of the…
The manifestation of the dark Universe begun with unexpected large scale astronomical observations. Here we are investigating the origin of small scale anomalies, like that of the annually observed temperature anomalies in the stratosphere.…
For main-sequence stars beyond spectral type M5 the characteristics of magnetic activity common to warmer solar-like stars change into the brown-dwarf domain: the surface magnetic field becomes more dipolar and the evolution of the field…