The Age-Rotation-Activity Relation: From Myrs to Gyrs

Дата и время публикации : 2010-11-30T23:21:58Z

Авторы публикации и институты :
Kevin R. Covey
Marcel A. Agueros
Jenna J. Lemonias
Nicholas M. Law
Adam L. Kraus

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: Contribution to Proceedings of Cool Stars 16 Workshop; 8 pages in ASP format; 3 figures
Первичная категория: astro-ph.SR

Все категории : astro-ph.SR

Краткий обзор статьи: 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 magnetic dynamo and angular momentum evolution, and provides a valuable age estimator for isolated field stars. While the age-rotation-activity relation has been studied extensively in clusters younger than 500 Myr, empirically measured rotation periods are scarce for older ages. Using the Palomar Transient Factory (PTF), we have begun a survey of stellar rotation to map out the late-stage evolution of the age-rotation-activity relation: the Columbia/Cornell/Caltech PTF (CCCP) survey of open clusters. The first CCCP target is the nearby ~600 Myr Hyades-analog Praesepe, where PTF has produced light curves spanning more than 3 months and containing >150 measurements for ~650 cluster members. Analyzing these light curves, we have measured rotation periods for 40 K & M cluster members, filling the gap between the periods previously reported for solar-type Hyads (Radick et al. 1987, Prosser et al. 1995) and for a handful of low-mass Praesepe members (Scholz et al. 2007). Our measurements indicate that Praesepe’s period-color relation undergoes at transition at a characteristic spectral type of ~M1 — from a well-defined singular relation at higher mass, to a more scattered distribution of both fast and slow-rotators at lower masses. The location of this transition is broadly consistent with expectations based on observations of younger clusters and the assumption that stellar-spin down is the dominant mechanism influencing angular momentum evolution at ~600 Myr. In addition to presenting the results of our photometric monitoring of Praesepe, we summarize the status and future of the CCCP survey.

Category: Physics