Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars

Research output: Contribution to journalArticlepeer-review

Standard

Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars. / Van Saders, Jennifer L.; Ceillier, Tugdual; Metcalfe, Travis S.; Aguirre, Victor Silva; Pinsonneault, Marc H.; García, Rafael A.; Mathur, Savita; Davies, Guy R.

In: Nature, Vol. 529, No. 7585, 14.01.2016, p. 181-184.

Research output: Contribution to journalArticlepeer-review

Harvard

Van Saders, JL, Ceillier, T, Metcalfe, TS, Aguirre, VS, Pinsonneault, MH, García, RA, Mathur, S & Davies, GR 2016, 'Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars', Nature, vol. 529, no. 7585, pp. 181-184. https://doi.org/10.1038/nature16168

APA

Van Saders, J. L., Ceillier, T., Metcalfe, T. S., Aguirre, V. S., Pinsonneault, M. H., García, R. A., Mathur, S., & Davies, G. R. (2016). Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars. Nature, 529(7585), 181-184. https://doi.org/10.1038/nature16168

Vancouver

Van Saders JL, Ceillier T, Metcalfe TS, Aguirre VS, Pinsonneault MH, García RA et al. Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars. Nature. 2016 Jan 14;529(7585):181-184. https://doi.org/10.1038/nature16168

Author

Van Saders, Jennifer L. ; Ceillier, Tugdual ; Metcalfe, Travis S. ; Aguirre, Victor Silva ; Pinsonneault, Marc H. ; García, Rafael A. ; Mathur, Savita ; Davies, Guy R. / Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars. In: Nature. 2016 ; Vol. 529, No. 7585. pp. 181-184.

Bibtex

@article{8b69dcb9ca084f29904ac9ad0a4f88a1,
title = "Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars",
abstract = "A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation1. The technique of {\textquoteleft}gyrochronology{\textquoteright} uses the rotation period of a star to calculate its age2, 3. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age4 (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology5, 6. The data for the cluster agree with previous period–age relations4, but these relations fail to describe the asteroseismic sample7. Here we report stellar evolutionary modelling5, 6, 8, 9, 10, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can—unlike existing models—reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.",
author = "{Van Saders}, {Jennifer L.} and Tugdual Ceillier and Metcalfe, {Travis S.} and Aguirre, {Victor Silva} and Pinsonneault, {Marc H.} and Garc{\'i}a, {Rafael A.} and Savita Mathur and Davies, {Guy R.}",
year = "2016",
month = jan,
day = "14",
doi = "10.1038/nature16168",
language = "English",
volume = "529",
pages = "181--184",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "7585",

}

RIS

TY - JOUR

T1 - Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars

AU - Van Saders, Jennifer L.

AU - Ceillier, Tugdual

AU - Metcalfe, Travis S.

AU - Aguirre, Victor Silva

AU - Pinsonneault, Marc H.

AU - García, Rafael A.

AU - Mathur, Savita

AU - Davies, Guy R.

PY - 2016/1/14

Y1 - 2016/1/14

N2 - A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation1. The technique of ‘gyrochronology’ uses the rotation period of a star to calculate its age2, 3. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age4 (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology5, 6. The data for the cluster agree with previous period–age relations4, but these relations fail to describe the asteroseismic sample7. Here we report stellar evolutionary modelling5, 6, 8, 9, 10, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can—unlike existing models—reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.

AB - A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation1. The technique of ‘gyrochronology’ uses the rotation period of a star to calculate its age2, 3. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age4 (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology5, 6. The data for the cluster agree with previous period–age relations4, but these relations fail to describe the asteroseismic sample7. Here we report stellar evolutionary modelling5, 6, 8, 9, 10, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can—unlike existing models—reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.

U2 - 10.1038/nature16168

DO - 10.1038/nature16168

M3 - Article

VL - 529

SP - 181

EP - 184

JO - Nature

JF - Nature

SN - 0028-0836

IS - 7585

ER -