Related papers: The lithium-rotation correlation for WTTS in Tauru…
Open clusters provide clues to understand the evolution of Li7 at the surface of low-mass stars and its possible correlation with stellar rotation, which is a challenge for both stellar hydrodynamics and Galactic chemical evolution. We aim…
High resolution (R=110000), very high S/N spectra, centered on the 6707.8A LiI line have been obtained with the ESO Coude Echelle Spectrometer for five, metal-poor (-0.8 < [Fe/H] < -0.6) disk stars in the turnoff region of the HR-diagram.…
We examine how tides, stellar evolution, and magnetic braking shape the rotation period (P$_{rot}$) evolution of low-mass stellar binaries up to orbital periods (P$_{orb}$) of 100 d across a wide range tidal dissipation parameters using two…
The pioneering study by Skumanich (1972) showed that the rotational velocity of G-type Main-Sequence (MS) stars decreases with stellar age according to $<v \sin i>$ $\propto$ $t^{-1/2}$. This relationship is consistent with simple theories…
Surface rotation rates of young solar-type stars display drastic changes at the end of the pre-main sequence through the early main sequence. This may trigger corresponding changes in the magnetic dynamos operating in these stars, which…
The understanding of the rotational evolution of early-type stars is deeply related to that of anisotropic mass and angular momentum loss. In this paper, we aim to clarify the rotational evolution of rapidly rotating early-type stars along…
The vast majority of stars with mass similar to the Sun are expected to only destroy lithium over the course of their lives, via low-temperature nuclear burning. This has now been supported by observations of hundreds of thousands of red…
Magnetic activity and rotation are related to the age of low-mass main sequence stars. To further constrain these relations, we study a sample of 574 main sequence stars members of common proper motion pairs with white dwarfs, identified…
We investigate the role of latitudinal differential rotation (DR) in the spin evolution of solar-type stars. Recent asteroseismic observation detected the strong equator-fast DR in some solar-type stars. Numerical simulations show that the…
We present a study of rotation across 30 square degrees of the Orion Star-forming Complex, following a $\sim$200 d photometric monitoring campaign by the Next Generation Transit Survey (NGTS). From 5749 light curves of Orion members, we…
Recent detection of the isotope $^7$Be (that decays into $^7$Li) in the outburst of classical novae confirms the suggestion made in the 70s that novae could make $^7$Li. We reconsidered the role of novae as producers of Li by means of a…
We present a comprehensive study of rotation, disk and accretion signatures for 144 T Tauri stars in the young (~2 Myr old) Chamaeleon I and Taurus-Auriga star forming regions based on multi-epoch high-resolution optical spectra from the…
We present theoretical models for the evolution of T Tauri stars surrounded by circumstellar discs. The models include the effects of pre-main-sequence stellar and time dependent disc evolution, and incorporate the effects of stellar…
Aims. We study the evolution of rotation and high energy X-ray, extreme ultraviolet (EUV), and Ly-alpha emission for F, G, K, and M dwarfs, with masses between 0.1 and 1.2 Msun, and provide our evolutionary code and a freely available set…
The problem of the determination of T Tauri stars masses and ages using their evolutionary status is discussed. We test of pre-main sequence evolutionary models of D'Antona \& Mazzitelli (1994), Dotter et al. (2008), Bressan et al. (2012)…
Using the Spitzer Space Telescope, we have observed 90 weak-line and classical T Tauri stars in the vicinity of the Ophiuchus, Lupus, Chamaeleon, and Taurus star-forming regions as part of the Cores to Disks (c2d) Spitzer Legacy project. In…
We present a study of the lithium abundances of a sample of evolved components of Chromospherically Active Binary Systems. We show that a significant part of them have lithium excesses, independently of their mass and evolutionary stage.…
Pre-main sequence models with inflated radii are needed to simultaneously reproduce the colour-magnitude diagram and the lithium depletion pattern in young open clusters. We tested a new set of PMS models including radius inflation due to…
We investigate the evolution of circumstellar discs around T Tauri stars that are ejected from small stellar clusters within molecular clouds. In particular, we study how the interaction that leads to ejection may hasten the transition…
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…