Related papers: Flare frequency in M dwarfs belonging to Young Mov…
We investigate the relationship between age and chromospheric activity for 139 M dwarf stars in wide binary systems with white dwarf companions. The age of each system is determined from the cooling age of its white dwarf component. The…
The relationship between age, rotation, and magnetic activity can be used to roughly estimate the ages of solar-type stars. At lower stellar masses, the relationship between activity and age changes due to the less efficient angular…
Stellar flares are intense bursts of radiation caused by magnetic reconnection on active stars. They are especially frequent on M dwarfs, where they can significantly influence the habitability of orbiting planets. Flare frequency…
Rotation is a directly-observable stellar property, and drives magnetic field generation and activity through a magnetic dynamo. Main sequence stars with masses below approximately 0.35Msun (mid-to-late M dwarfs) are fully-convective, and…
The statistical characteristic of stellar flares at optical bands has received an extensive study, but it remains to be studied at soft X-ray bands, in particular for solar-type stars. Here, we present a statistical study of soft X-ray…
We present a spectroscopic study and dynamical analysis of ~2600 M7 dwarfs. We confirm our previous finding that the fraction of magnetically active stars decreases with vertical distance from the Galactic plane. We also show that the mean…
We report on two millimeter flares detected by ALMA at 220 GHz from AU Mic, a nearby M dwarf. The larger flare had a duration of only $\sim35$ sec, with peak $L_{R}=2\times10^{15}$ erg s$^{-1}$ Hz$^{-1}$, and lower limit on linear…
Pulsation powered by deuterium burning in brown dwarfs and very low mass stars has been put forth (Palla & Baraffe 2005) as a novel probe of the interiors of these objects in the 1-15 Myr age range. Previous observations have hinted at…
Based on analysis of photometric observations of nearby M type stars obtained with ASAS, 31 periodic variables were detected. The determined periods are assumed to be related to rotation periods of the investigated stars. Among them 10 new…
The interaction between the magnetic fields of late-type stars and their close-by planets may produce stellar flares as observed in active binary systems. However, in spite of several claims, conclusive evidence is still lacking. We…
The spectral energy distribution, variability and evolution of the high-energy radiation from an M dwarf planet host is crucial in understanding the planet's atmospheric evolution and habitability and in interpreting the planet's spectrum.…
Young Moving Groups (YMGs) are close (<100pc), coherent collections of young (<100Myr) stars that appear to have formed in the same star-forming molecular cloud. As such we would expect their individual initial mass functions (IMFs) to be…
We analyzed the light curves of 1376 early-to-late, nearby M dwarfs to search for white-light flares using photometry from the All-Sky Automated Survey for Supernovae (ASAS-SN). We identified 480 M dwarfs with at least one potential flare…
M dwarfs show the highest rocky planet occurrence among all spectral types, in some instances within the Habitable Zone. Because some of them are very active stars, they are often subject to frequent and powerful flaring, which can be a…
Observations made using TESS revealed a sample of low mass stars which show a periodic modulation on a period $<0.2$~d. Surprisingly many of these Ultra Fast Rotating (UFR) stars showed no evidence of flare activity which would be expected…
We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism…
We have examined the relationship between rotation and activity in 14 late-type (M6-M7) M dwarfs, using high resolution spectra taken at the Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most are inactive…
M-dwarfs are common stellar hosts of habitable-zone exoplanets. NUV radiation can severely impact the atmospheric and surface conditions of such planets, making characterization of NUV flaring activity a key aspect in determining…
The distribution of small-scale magnetic fields in stellar photospheres is an important ingredient in our understanding of the magnetism of low mass stars. Their spatial distribution connects the field generated in the stellar interior with…
We explore the empirical power-law relationship between X-ray luminosity (Lx) and total surface magnetic flux (Phi), established across solar magnetic elements, time- and disk-averaged emission from the Sun, older active stars, and…