Rotational evolution of solar-type stars. I - Main-sequence evolution

MacGregor, K. B.; Brenner, M.

doi:10.1086/170269

Cited by 168 publications

(172 citation statements)

References 0 publications

Supporting

Mentioning

168

Contrasting

Order By: Relevance

“…It undergoes dramatic changes in stellar life, as shown by observational studies and also predicted by evolutionary models of angular momentum (Kawaler 1988;MacGregor & Brenner 1991;Krishnamurthi et al 1997;Bouvier et al 1997;Sills et al 2000;Ivanova & Taam 2003;Holzwarth & Jardine 2007). On one hand, the properties of magnetic fields depend on rotation and mass; on the other, they play a fundamental role in altering the rotational properties of late-type stars.…”

Section: Introductionmentioning

confidence: 95%

RACE-OC project: rotation and variability in the open cluster M 11 (NGC 6705)

Messina

Parihar

Koo

et al. 2010

A&A

View full text Add to dashboard Cite

Context. 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 the strength and topology of the magnetic fields. Open clusters represent especially useful targets for investigating the connection among rotation, activity, and age. Over time, stellar activity and rotation evolve, providing us with a promising diagnostic tool to determine the age of the field stars.Aims. The open cluster M11 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which aims to explore the evolution of rotation and magnetic activity in the late-type members of open clusters with different ages. Methods. Photometric observations of the open cluster M 11 were carried out in June 2004 using the LOAO 1 m telescope. The rotation periods of the cluster members were determined by Fourier analysis of photometric data time series. We investigated the relations between the surface activity, characterized by the light curve amplitude, and rotation. Results. We have discovered a total of 75 periodic variables in the M 11 FoV, of which 38 are candidate cluster members. Specifically, among cluster members we discovered 6 early-type periodic variables, 2 eclipsing binaries, and 30 bona-fide single periodic late-type variables. Considering the rotation periods of 16 G-type members of the almost coeval 200-Myr M 34 cluster, we could determine the rotation period distribution from a more numerous sample of 46 single G stars at an age of about 200-230 Myr and determine a median rotation period of P = 4.8 d. Conclusions. A comparison with the younger M 35 cluster (∼150 Myr) and with the older M37 cluster (∼550 Myr) shows that G stars rotate more slowly than younger M 35 stars and more rapidly than older M 37 stars. The measured variation in the median rotation period is consistent with the scenario of rotational braking of main-sequence spotted stars as they age. Finally, G-type M11 members have a level of photospheric magnetic activity, as measured by light curve amplitude, comparable to what is observed in the younger 110-Myr Pleiades stars of similar mass and rotation.

show abstract

Section: Introductionmentioning

confidence: 95%

RACE-OC project: rotation and variability in the open cluster M 11 (NGC 6705)

Messina

Parihar

Koo

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

“…Following this early evolutionary phase, the amount of angular momentum stored by a star before it reaches the zero-age main sequence (hereafter ZAMS) can be determined by the gains and losses regulated by the accretion, winds (Schatzman 1962;Shu et al 2000), and locking with the circumstellar environments with magnetic fields (Königl 1991;Edwards et al 1993). The shaping of the internal distribution of the stored angular momentum is certainly a matter of hydrodynamical instabilities (Endal & Sofia 1981;Stauffer et al 1984;Pinsonneault et al 1990;MacGregor & Brenner 1991;Keppens et al 1995;Soderblom et al 1993Soderblom et al , 2001, couplings between Full Table 1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/537/A120…”

Section: Introductionmentioning

confidence: 99%

Rotational velocities of A-type stars

Zorec

Royer

2012

A&A

239

248

View full text Add to dashboard Cite

Context. In previous works of this series, we have shown that late B-and early A-type stars have genuine bimodal distributions of rotational velocities and that late A-type stars lack slow rotators. The distributions of the surface angular velocity ratio Ω/Ω crit (Ω crit is the critical angular velocity) have peculiar shapes according to spectral type groups, which can be caused by evolutionary properties. Aims. We aim to review the properties of these rotational velocity distributions in some detail as a function of stellar mass and age. Methods. We have gathered v sin i for a sample of 2014 B6-to F2-type stars. We have determined the masses and ages for these objects with stellar evolution models. The (T eff , log L/L )-parameters were determined from the uvby-β photometry and the HIPPARCOS parallaxes.Results. The velocity distributions show two regimes that depend on the stellar mass. Stars less massive than 2.5 M have a unimodal equatorial velocity distribution and show a monotonical acceleration with age on the main sequence (MS). Stars more massive have a bimodal equatorial velocity distribution. Contrarily to theoretical predictions, the equatorial velocities of stars from about 1.7 M to 3.2 M undergo a strong acceleration in the first third of the MS evolutionary phase, while in the last third of the MS they evolve roughly as if there were no angular momentum redistribution in the external stellar layers. The studied stars might start in the ZAMS not necessarily as rigid rotators, but with a total angular momentum lower than the critical one of rigid rotators. The stars seem to evolve as differential rotators all the way of their MS life span and the variation of the observed rotational velocities proceeds with characteristic time scales δt ≈ 0.2 t MS , where t MS is the time spent by a star in the MS.

show abstract

“…The envelope initially spins down in response to the wind torque, and the core responds on an internal transport timescale; there will therefore be a detectable transient phase of anomalously slow surface rotation if the transport timescale is of order tens of Myr or longer. This core-envelope decoupling can have a large effect on the surface rotation rate as the star ages (Pinsonneault et al 1990;MacGregor & Brenner 1991) The resulting phenomenological models can successfully reproduce many of the observed time dependence of stellar rotation in open cluster stars (see for example Gallet & Bouvier 2013, Lanzafame & Spada 2015. However, the resulting solutions have numerous free parameters and there could be severe physical degeneracies between them.…”

Section: Introductionmentioning

confidence: 99%

Evidence for Cluster to Cluster Variations in Low-Mass Stellar Rotational Evolution

Coker

Pinsonneault

Terndrup

2016

ApJ

View full text Add to dashboard Cite

A concordance model for angular momentum evolution has been developed by multiple investigators. This approach postulates that star forming regions and clusters are an evolutionary sequence which can be modeled with assumptions about the coupling between protostars and accretion disks, angular momentum loss from magnetized winds that saturates in a mass-dependent fashion at high rotation rates, and core-envelope decoupling for solar analogs. We test this approach by combining established data with the large h Per dataset from the MONITOR project and new low-mass Pleiades data. We confirm prior results that young low-mass stars can be used to test star-disk coupling and angular momentum loss independent of the treatment of internal angular momentum transport. For slow rotators, we confirm the need for star-disk interactions to evolve the ONC to older systems, using h Per (age 13 Myr) as our natural post-disk case. Further interactions are not required to evolve slow rotators from h Per to older systems, implying no justification for extremely long-lived disks as an alternative to core-envelope decoupling. However, our wind models cannot evolve rapid rotators from h Per to older systems consistently; this appears to be a general problem for any wind model that becomes ineffective in low-mass young stars. We outline two possible solutions: either there is cosmic variance in the distribution of stellar rotation rates in different clusters or there are substantially enhanced torques in low-mass rapid rotators. We favor the former explanation and discuss observational tests that could be used to distinguish them. If the distribution of initial conditions depends on environment, models which test parameters by assuming a universal underlying distribution of initial conditions will need to be re-evaluated.

show abstract

Rotational evolution of solar-type stars. I - Main-sequence evolution

Cited by 168 publications

References 0 publications

RACE-OC project: rotation and variability in the open cluster M 11 (NGC 6705)

RACE-OC project: rotation and variability in the open cluster M 11 (NGC 6705)

Rotational velocities of A-type stars

Evidence for Cluster to Cluster Variations in Low-Mass Stellar Rotational Evolution

Contact Info

Product

Resources

About