相关论文: Rotation and activity in late-type members of the …
Star clusters are key to understand the stellar and Galactic evolution. ASCC 123 is a little-studied, nearby and very sparse open cluster. We performed the first high-resolution spectroscopic study of this cluster in the framework of the…
Asteroseismic modelling of isolated star presents significant challenges due to the difficulty in accurately determining stellar parameters, particularly the stellar age. These challenges can be overcomed by observing stars in open…
Open clusters serve as a useful tool for calibrating models of the relationship between mass, rotation, and age for stars with an outer convection zone due to the homogeneity of the stars within the cluster. Cluster to cluster comparisons…
The nearby open cluster NGC 752 presents a rare opportunity to study stellar properties at ages >1 Gyr. However, constructing a membership catalog for it is challenging; most surveys have been limited to identifying its giants and dwarf…
We have searched for stellar activity cycles in late low mass M dwarfs (M0--M6) located in the TESS north and south continuous viewing zones using data from sectors 1--61 (Cycle 1 to part way through Cycle 5). We utilise TESS-SPOC data…
We present results from ACS and WFPC observations in the low luminosity galaxy NGC 45. We identified 28 young star cluster candidates. While the exact values of age, mass, and extinction depend somewhat on the choice of SSP models, we find…
Over the past 40 years, observational surveys have established the existence of a tight relationship between a star's age, rotation period, and magnetic activity. This age-rotation-activity relation documents the interplay between a star's…
The ages of pulsating stars in clusters can be determined by isochrone fitting and it can be further improved by asteroseismic modelling. We analyse the intermediate-age open cluster NGC2477, known to suffer from differential extinction, to…
Our goal is to determine the rotational and magnetic-related activity properties of stars at different stages of evolution. We have focussed our attention on 6 young loose stellar associations within 100 pc and ages in the range 8-70 Myr:…
Rotation and magnetic activity are intimately linked in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on stellar rotation, and rotation itself is strongly influenced by strength and…
Open clusters offer us the means to study stellar properties in samples with well-defined ages and initial chemical composition. Here we present a survey of projected rotational velocities for a large sample of mainly B-type stars in young…
The Transiting Exoplanet Survey Satellite (TESS) has observed nearly the entire sky, producing full-frame images (FFIs) every 30 min (Cycles 1$-$2), 10 min (Cycles 3$-$4), and now 200 s (Cycle 5+), over 27-day sectors. Light curves…
We present the results of a combination of new stellar rotation periods and extensive information about membership in the young open clusters M35 and M34. The observations show that late-type members of both clusters divide into two…
We present the results of a monitoring campaign aimed at deriving rotation periods for a representative sample of stars in the young (30 Myr) open cluster IC 2602. Rotation periods were derived for 29 of 33 stars monitored. The periods…
We study a sample of 21 young and active solar-type stars with spectral types ranging from late F to mid K and characterize the behaviour of their activity. We apply the continuous period search (CPS) time series analysis method on 16 to 27…
The evolution of magnetism in late-type dwarfs remains murky, as we can only weakly predict levels of activity for M dwarfs of a given mass and age. We report results from our spectroscopic survey of M dwarfs in the Southern Continuous…
We present a photometric study of I-band variability in the young association Cepheus OB3b. The study is sensitive to periodic variability on timescales of less than a day, to more than 20 days. After rejection of contaminating objects…
Rotation and solar-type magnetic activity are closely related to each other in stars of G or later spectral types. Presence and level of magnetic activity depend on star's rotation and rotation itself is strongly influenced by strength and…
Kepler ultra-high precision photometry of long and continuous observations provides a unique dataset in which surface rotation and variability can be studied for thousands of stars. Because many of these old field stars also have…
We analyze TESS data to explore stellar flares and rotational characteristics in members of Nearby Young Moving Groups (NYMGs). Our study focuses on 417 members of NYMGs aged 10-150 Myr. Using detrended light curves from the TESS Science…