Outputs (5)

A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group (2013)
Journal Article
Binks, A. S., & Jeffries, R. D. (2014). A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group. Monthly Notices of the Royal Astronomical Society: Letters, 438(1), L11-L15. https://doi.org/10.1093/mnrasl/slt141

Optical spectroscopy is used to confirm membership for eight low-mass candidates in the young Beta Pic moving group (BPMG) via their radial velocities, chromospheric activity and kinematic parallaxes. We searched for the presence of the Li I 6708 Å r... Read More about A lithium depletion boundary age of 21 Myr for the Beta Pictoris moving group.

A lithium depletion boundary age of 22 Myr for NGC 1960 (2013)
Journal Article
Jeffries, R. D., Naylor, T., Mayne, N. J., Bell, C. P. M., & Littlefair, S. P. (2013). A lithium depletion boundary age of 22 Myr for NGC 1960. Monthly Notices of the Royal Astronomical Society, 434(3), 2438-2450. https://doi.org/10.1093/mnras/stt1180

We present a deep Cousins RI photometric survey of the open cluster NGC 1960, complete to RC ≃ 22, IC ≃ 21, that is used to select a sample of very low mass cluster candidates. Gemini spectroscopy of a subset of these is used to confirm membership an... Read More about A lithium depletion boundary age of 22 Myr for NGC 1960.

No evidence for intense, cold accretion on to YSOs from measurements of Li in T-Tauri stars (2013)
Journal Article
Sergison, D. J., Mayne, N. J., Naylor, T., Jeffries, R. D., & Bell, C. P. M. (2013). No evidence for intense, cold accretion on to YSOs from measurements of Li in T-Tauri stars. Monthly Notices of the Royal Astronomical Society, 434(2), 966-977. https://doi.org/10.1093/mnras/stt973

We have used medium-resolution spectra to search for evidence that proto-stellar objects accrete at high rates during their early ‘assembly phase’. Models predict that depleted lithium and reduced luminosity in T-Tauri stars are key signatures of ‘co... Read More about No evidence for intense, cold accretion on to YSOs from measurements of Li in T-Tauri stars.

Pre-main-sequence isochrones – II. Revising star and planet formation time-scales (2013)
Journal Article
Bell, C. P. M., Naylor, T., Mayne, N. J., Jeffries, R. D., & Littlefair, S. P. (2013). Pre-main-sequence isochrones – II. Revising star and planet formation time-scales. Monthly Notices of the Royal Astronomical Society, 434(1), 806-831. https://doi.org/10.1093/mnras/stt1075

We have derived ages for 13 young (<30 Myr) star-forming regions and find that they are up to a factor of 2 older than the ages typically adopted in the literature. This result has wide-ranging implications, including that circumstellar discs survive...

Angular momentum evolution of cool stars: Toward a synthesis of observations and theory before and after the ZAMS (2013)
Journal Article
Meibom, S., Barnes, S., Covey, K., Jeffries, R., Matt, S., Morin, J., …Irwin, J. (2013). Angular momentum evolution of cool stars: Toward a synthesis of observations and theory before and after the ZAMS. Astronomische Nachrichten, 334(1-2), 168-171. https://doi.org/10.1002/asna.201211777

The coexistence of fast and slowly rotating cool stars in ZAMS clusters – forming distinct sequences in the color vs. rotation period plane – is providing clues to differences in their pre main-sequence angular momentum evolution. This Cool Stars 17... Read More about Angular momentum evolution of cool stars: Toward a synthesis of observations and theory before and after the ZAMS.