Related papers: Accretion-induced luminosity spreads in young clus…

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…

The low spin rates measured for solar-type stars at an age of a few Myr (~10% of the break-up velocity) indicate that some mechanism of angular momentum regulation must be at play in the early pre-main sequence. We characterize the rotation…

Many young clusters possess extended main sequences, a phenomenon commonly ascribed to stellar rotation. However, the mechanism behind their very wide stellar rotation distributions remains unclear. A proposed explanation is that magnetic…

We use the Geneva Syclist isochrone models that include the effects of stellar rotation to investigate the role that rotation has on the resulting colour-magnitude diagram (CMD) of young and intermediate age clusters. We find that if a…

Gravitational interactions in very young high-density stellar clusters can to some degree change the angular momentum in the circumstellar discs surrounding initially the majority of stars. However, for most stars the cluster environment…

The standard picture of accretion is a steady flow of matter from the disc onto the young star - a concept which assumes the star-disc system to be completely isolated. However, in a dense cluster environment star-disc systems do interact…

We have determined new rotation periods for 404 stars in the Orion Nebula Cluster using the Wide Field Imager attached to the MPG/ESO 2.2 m telescope on La Silla, Chile. Mass estimates are available for 335 of these and most have M < 0.3…

Stellar rotation, age spread and binary stars are thought to be three most possible causes of the peculiar color-magnitude diagrams (CMDs) of some star clusters, which exhibit extended main-sequence turn-offs (eMSTOs). It is far from…

The radii of young pre-main-sequence (PMS) stars in the Orion Nebula Cluster (ONC) have been estimated using their rotation periods and projected equatorial velocities. Stars at a given effective temperature have a spread in their…

Rotation periods are now available for ~500 pre-main sequence and recently arrived main sequence stars of solar-like mass (0.4-1.2 M_sun) in five nearby young clusters: the Orion Nebula Cluster, NGC 2264, alpha Per, IC 2602 and the…

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…

We examine the early angular momentum history of stars in young clusters via 197 photometric periods in the Orion Flanking Fields, 83 photometric periods in NGC 2264, and 256 measurements of v sin i in the ONC. We show that PMS stars, even…

We present the results of a detailed kinematic analysis of a significant fraction of the known population of Galactic star clusters aimed at constraining the physical mechanisms driving the onset and evolution of cluster rotation. Our study…

We re-analyze all archival Chandra/ACIS observations of the Orion Nebula Cluster (ONC) to study the X-ray properties of a large sample of pre--main-sequence (PMS) stars with optically determined rotation periods. Our goal is to elucidate…

We present a photometric study of I-band variability in the young cluster IC 348. The main purpose of the study was to identify periodic stars. In all we find 50 periodic stars, of which 32 were previously unknown. For the first time in IC…

Observations of PMS star rotation periods reveal slow rotators in young clusters of various ages, indicating that angular momentum is somehow removed from these rotating masses. The mechanism by which spin-up is regulated as young stars…

The Orion Nebula Cluster (ONC) is the most massive region of active star formation within a kpc of the Sun. Using Gaia DR3 parallaxes and proper motions, we examine the bulk motions of stars radially and tangentially relative to the cluster…

Although the Orion Nebula Cluster is one of the most studied clusters in the solar neighborhood, the evolution of the very low-mass members ($M_* < 0.25 \, M_\odot$) has not been fully addressed due to their faintness. Our goal is to verify…

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 present observational understanding of the evolution of the mass accretion rates (Macc) in pre-main sequence stars is limited by the lack of accurate measurements of Macc over homogeneous and large statistical samples of young stars.…