The rotation - Lithium depletion correlation in the Beta Pictoris association and the LDB age determination

MESSINA, S.; LANZAFAME, A.; FEIDEN, G.; MILWARD, M.; DESIDERA, S.; BUCCINO, A. P. ; CURTIS, I. ; JOFRE, E.; KEHUSMAA, P.; MEDHI, B.; MONARD, B.; PETRUCCI, R.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2016 vol. 596

0004-6361

Context. There is evidence in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, thatrotation plays a key role in the Lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be lessLi-depleted than equal-mass slow rotators.Aims. We intend to explore the existence of a Li depletion - rotation connection among the β Pictoris members at anage of about 24 Myr, and to use such correlation either to confirm or to improve the age estimate based on the LithiumDepletion Boundary (LDB) modeling.Methods. We have photometrically monitored all the known members of the β Pictoris association with at least oneLithium equivalent width (Li EW) measurement from the literature.Results. We measured the rotation periods of 30 members for the first time and retrieved from the literature the rotationperiods for other 36 members, building a catalogue of 66 members with measured rotation period and Li EW.Conclusions. We find that in the 0.3 < M < 0.8 M range, there is a strong correlation between rotation and Li EW.For higher mass stars, no significant correlation is found. For very low mass stars in the Li depletion onset, at about0.1 M , data are too few to infer a significant correlation. The observed Li EWs are compared with those predictedby the Dartmouth stellar evolutionary models that incorporate the effects of magnetic fields. After decorrelating the LiEW from the rotation period, we find that the hot side of the LDB is fitted well by Li