Related papers: Magnetic evolution of complex solar active regions

Transition region explosive events have long been suggested as direct signatures of magnetic reconnection in the solar atmosphere. In seeking further observational evidence to support this interpretation, we study the relation between…

We studied the formation of a pore in AR NOAA 11462. We analysed data obtained with the IBIS at the DST on April 17, 2012, consisting of full Stokes measurements of the Fe I 617.3 nm lines. Furthermore, we analysed SDO/HMI observations in…

Magnetic activity is a ubiquitous feature of stars with convective outer layers, with implications from stellar evolution to planetary atmospheres. Investigating the mechanisms responsible for the observed stellar activity signals from days…

We study the different patterns of interannual magnetic variability in stars on or near the lower main sequence, approximately solar-type (G-K dwarf) stars in time series of 36 years from the Mount Wilson Observatory Ca\,{\sc ii}\,H\&K…

Most of the emission coming from the solar corona is confined into closed magnetic structures in the form of arcs (loops). Very little is known about the structure of stellar coronae. The magnetic topology, however, can be inferred by…

Predicting the severity of the solar eruptive phenomena like flares and Coronal Mass Ejections (CMEs) remains a great challenge despite concerted efforts for several decades. The advent of high quality vector magnetograms obtained from…

We study variations of the lifetimes of high-degree solar p-modes in the quiet and active Sun with the solar activity cycle. The lifetimes in the degree range 300 - 600 and frequency 2.5 - 4.5 mHz were computed from SOHO/MDI data in an area…

There is a large change in surface rotation rates of sun-like stars on the pre-main sequence and early main sequence. Since these stars have dynamo driven magnetic fields, this implies a strong evolution of their magnetic properties over…

The energy release and build-up processes in the solar corona have significant implications in particular for the case of large recurrent flares, which pose challenging questions about the conditions that lead to the episodic energy release…

A detailed investigation of the magnetic properties of young Sun-like stars can provide valuable information on our Sun's magnetic past and its impact on the early Earth. We determine the properties of the moderately rotating young Sun-like…

A process of diffusion of small-scale magnetic elements inside four active regions (ARs) was analyzed. Line-of-sight magnetograms acquired by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamic Observatory (SDO) during a…

We study intensity variations, as measured by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO), in a solar coronal arcade using a newly developed analysis procedure that employs spatio-temporal…

The Sun's variability is controlled by the progression and interaction of the magnetized systems that form the 22-year magnetic activity cycle (the "Hale Cycle'') as they march from their origin at $\sim$55 degrees latitude to the equator,…

We carry out numerical simulations of the surface evolution of bipolar magnetic regions (BMRs) and magnetic spots on stars, which have radii and surface rotational shears of AB Doradus, the Sun, and the HR 1099 primary. The surface flux…

The pre-CME structure is of great importance to understanding the origin of CMEs, which, however, has been largely unknown for CMEs originating from active regions. In this paper, selected for studying are 16 active-region coronal arcades…

Magnetic cycles have been detected in tens of solar-like stars. The relationship between the cycle properties and global stellar parameters is not fully understood yet. We searched for activity cycles in 90 solar-like stars with ages…

This paper introduces a new empirical model for the rotational evolution of Sun-like stars -- those with surface convection zones and non-convective interior regions. Previous models do not match the morphology of observed (rotation…

Solar coronal plasma composition is typically characterized by first ionization potential (FIP) bias. Using spectra obtained by Hinode's EUV Imaging Spectrometer (EIS) instrument, we present a series of large-scale, spatially resolved…

Earth is the only planet known to harbor life, therefore we may speculate on how the nature of the Sun-Earth interaction is relevant to life on Earth, and how the behavior of other stars may influence the development of life on their…

The age-metallicity relation (AMR) is a fundamental observational constraint for understanding how the Galactic disc formed and evolved chemically in time. However, there is not yet an agreement on the observational properties of the AMR…