Related papers: Long-lived coronal loops in solar active regions
One scenario proposed to explain the million degrees solar corona is a finely-stranded corona where each strand is heated by a rapid pulse. However, such fine structure has neither been resolved through direct imaging observations nor…
Fine-scale structure in the corona appears not to be well resolved by current imaging instruments. Assuming this to be true offers a simple geometric explanation for several current puzzles in coronal physics, including: the apparent…
Coronal loops, constituting the basic building blocks of the active Sun, serve as primary targets to help understand the mechanisms responsible for maintaining multi-million Kelvin temperatures in the solar and stellar coronae. Despite…
Coronal loops are building blocks of solar active regions. However, their formation mechanism is still not well understood. Here we present direct observational evidence for the formation of coronal loops through magnetic reconnection as…
The solar corona is much hotter than the photosphere and chromosphere, but the physical mechanism responsible for heating the coronal plasma remains unidentified yet. The thermal microwave emission, which is produced in strong magnetic…
Coronal loop observations have existed for many decades yet the precise shape of these fundamental coronal structures is still widely debated since the discovery that they appear to undergo negligible expansion between their footpoints and…
Coronal loops reveal crucial information about the nature of both coronal magnetic fields and coronal heating. The shape of the corresponding flux tube cross section and how it varies with position are especially important properties. They…
The energy balance in the corona of the Sun is the key to the long-standing coronal heating dilemma, which could be potentially revealed by observational studies of decayless kink oscillations of coronal plasma loops. A bundle of very long…
New and advanced space-based observing facilities continue to lower the resolution limit and detect solar coronal loops in greater detail. We continue to discover even finer sub-structures within coronal loop cross sections, in order to…
The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active region to address the role of field-line…
The characteristic electron densities, temperatures, and thermal distributions of 1MK active region loops are now fairly well established, but their coronal magnetic field strengths remain undetermined. Here we present measurements from a…
Coronal loops trace out bipolar, arch-like magnetic fields above the Sun's surface. Recent measurements that combine rotational tomography, extreme ultraviolet imaging, and potential-field extrapolation have shown the existence of large…
Previous studies have found that coronal loops have a nearly uniform thickness, which seems to disagree with the characteristic expansion of active region magnetic fields. This is one of the most intriguing enigmas in solar physics. We here…
The high densities, long lifetimes, and narrow emission measure distributions observed in coronal loops with apex temperatures near 1 MK are difficult to reconcile with physical models of the solar atmosphere. It has been proposed that the…
Decayless kink oscillations are omnipresent in the solar atmosphere and a viable candidate for coronal heating. Though there have been extensive studies of decayless oscillations in coronal loops with a few hundred Mm lengths, the…
Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…
The heating of the solar corona and the puzzle of the slender high reaching magnetic loops seen in observations from the Transition Region And Coronal Explorer(TRACE) has been investigated through 3D numerical simulations, and found to be…
Decayless kink oscillations, characterized by their lack of decay in amplitude, have been detected in coronal loops of varying scales in active regions, quiet Sun and coronal holes. Short-period (< 50 s) decayless oscillations have been…
In coronal loop modeling, it is commonly assumed that the loops are semi-circular with a uniform cross-sectional area. However, observed loops are rarely semi-circular, and extrapolations of the magnetic field show that the field strength…
Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood. We study the…