Related papers: Transient Emissions from Radio-Active Stars: Impli…
Magnetic storms on stars manifest as remarkable, randomly occurring changes of the luminosity over durations that are tiny in comparison to the normal evolution of stars. These stellar flares are bursts of electromagnetic radiation from…
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…
Radio emission has been detected from all the stages of stellar evolution across the HR Diagram. Its presence reveals both astrophysical phenomena and stellar activity which, otherwise, would not be detectable by other means. The…
Solar-type stars have been observed to flare at optical wavelengths to energies much higher than observed for the Sun. To date, no counterparts have been observed at longer wavelengths. We have searched the the VLA Sky Survey (VLASS) for…
Observations of nearby star forming clouds with imaging X-ray telescopes have revealed that X-ray emission is elevated $10^1-10^4$ above main sequence levels in low-mass pre-main sequence (PMS) stars. The variability and spectral X-ray…
Radio observations of stars trace the plasma conditions and magnetic field properties of stellar magnetospheres and coronae. Depending on the plasma conditions at the emitter site, radio emission in the metre- and decimetre-wave bands is…
Although the majority of hot magnetic stars have extremely stable, $\sim$kG strength surface magnetic fields with simple topologies, a subset undergo small-scale explosions due to centrifugal breakout (CBO). The resulting small-scale flares…
Detectable radio emission occurs during almost all phases of massive star evolution. I will concentrate on the thermal and non-thermal continuum emission from early-type stars. The thermal radio emission is due to free-free interactions in…
We report on the first moderate-length time-scale observations of a young stellar object (YSO) at microwave frequencies. V830 Tau was monitored over the course of eight days with the JVLA at a frequency range of 4-8 GHz. Previous brief…
Radio detections of stellar systems provide a window onto stellar magnetic activity and the space weather conditions of extrasolar planets, information that is difficult to attain at other wavelengths. There have been recent advances…
The common - arguably ubiquitous - large-scale variability of optical and UV lines profiles of hot, massive stars is widely interpreted as the direct consequence of structured, variable winds. Many of the variability phenomena are observed…
A subset of magnetic stars exhibit periodic radio pulses produced by the coherent electron cyclotron maser mechanism. These pulses are known to exhibit both temporal and spectral variations, which have been attributed to phenomena intrinsic…
Stellar magnetic activity is a source of noise in the study of the transits of extrasolar planets. It induces flux variations which affect significantly the transit depth determination and the derivations of planetary and stellar…
Stars exhibit a bewildering variety of variable behaviors ranging from explosive magnetic flares to stochastically changing accretion to periodic pulsations or rotations. The principal LSST surveys will have cadences too sparse and…
Coherent low-frequency ($\lesssim 200$ MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events, and space weather. Previous low-frequency searches for radio emitting stellar systems have lacked the…
Variability is a defining characteristic of young stellar systems, and optical variability has been heavily studied to select and characterize the photospheric properties of young stars. In recent years, multi-epoch observations sampling a…
Young stars show a variety of highly energetic phenomena, from accretion and outflow processes to hot coronal plasmas confined in their outer atmosphere, all regulated by the intense stellar magnetic fields. Many aspects on each of these…
Stellar magnetic activity, manifested through spots (faculae and flares), fundamentally shapes the exoplanets' environments. For low-mass stars in particular, where most habitable-zone planets reside, the variable magnetic phenomena can…
Stellar flares are short-duration ($<$ hours) bursts of radiation associated with surface magnetic reconnection events. Stellar magnetic activity generally decreases as a function of both age and Rossby number, $R_0$, a measure of the…
Transient outbursts from magnetars have shown to be a key property of their emission, and one of the main way to discover new sources of this class. From the discovery of the first transient event around 2003, we now count about a dozen of…