Related papers: Rotational evolution of very low mass objects and …
I present the results of a multiyear survey of very low mass stars and brown dwarfs, at high spectral resolution. The spectra were gathered with the HIRES echelle at the Keck Observatory. Some of these objects are stellar and others are…
Late-type main sequence stars exhibit an x-ray to bolometric flux ratio that depends on ${\tilde Ro}$, the ratio of rotation period to convective turnover time, as ${\tilde Ro}^{-\zeta}$ with $2\le \zeta \le 3$ for ${\tilde Ro} >0.13$, but…
I review the development of ideas regarding the angular momentum evolution of solar-type stars, from the early 60's to the most recent years. Magnetic fields are the central agent that dictates the rotational evolution of solar-type stars,…
Very massive stars (VMS) dominate the physics of young clusters due to their ionising radiation and extreme stellar winds. It is these winds that determine their lifepaths until expiration. Observations in the Arches cluster show that VMS…
We present results from a high-resolution spectroscopic survey of 45 L dwarfs, which includes both very low-mass stars and brown dwarfs. Our spectra allow us to derive a significant number of new rotational velocities, and discover a slowly…
Major photometric monitoring campaigns of star-forming regions in the past decade have provided rich rotation period distributions of pre-main-sequence stars. The rotation periods span more than an order of magnitude in period, with most…
Rotation is a key parameter in the evolution of stars. From 1 Myr (the age of the ONC) to 4.5 Gyr (the age of the Sun), solar-like stars lose about 1-2 orders of specific angular momentum. The main agents for this rotational braking are…
We present a rotational velocity (vsini) survey of 32 stellar/substellar objects and giant planets using Keck/KPIC high-resolution spectroscopy, including 6 giant planets (2-7 M$_\mathrm{Jup}$) and 25 substellar/stellar companions (12-88…
The observed mass-age-rotation relationship in open clusters shows the progressive development of a slow-rotators sequence. The observed clustering on this sequence suggests that it corresponds to some equilibrium or asymptotic condition…
To better understand the observed distributions of rotation rate and magnetic activity of sun-like and low-mass stars, we derive a physically motivated scaling for the dependence of the stellar-wind torque on Rossby number. The torque also…
The surface rotation rates of young solar-type stars vary rapidly with age from the end of the pre-main sequence through the early main sequence. Important changes in the dynamos operating in these stars may result from this evolution,…
Stellar winds govern the angular momentum evolution of solar-like stars throughout their main-sequence lifetime. The efficiency of this process depends on the geometry of the star's magnetic field. There has been a rapid increase recently…
We present a model for the rotational evolution of a young, solar-mass star interacting magnetically with an accretion disk. As in a previous paper (Paper I), the model includes changes in the star's mass and radius as it descends the…
Surveys of young star-forming regions have discovered a growing population of planetary-mass (<13 M_Jup) companions around young stars. There is an ongoing debate as to whether these companions formed like planets (that is, from the…
Rotation evolution of late-type stars is dominated by magnetic braking and the underlying factors that control this angular momentum loss are important for the study of stellar spin-down. In this work, we study angular momentum loss as a…
Rapidly rotating late M dwarfs are observed in two different branches of magnetic activity, although they operate in the same stellar parameter range. Current empirical evidence indicates that M dwarfs with spectral types ranging from M3 /…
The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of angular momentum loss depends on the strength and morphology of the magnetic field, the…
Mass loss due to line-driven winds is central to our understanding of the evolution of massive stars. We extend the evolution models introduced in Paper I, where the mass loss recipe is based on the simultaneous calculation of the wind…
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…
We report on two photometric monitoring campaigns of Very Low Mass (VLM) objects in the young open cluster around SigmaOrionis. Our targets were pre-selected with multi-filter photometry in a field of 0.36 sqdeg. For 23 of these objects,…