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相关论文: Lithium, rotation and metallicity in the open clus…

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We present an analysis of high quality spectra of members of the young cluster M35. By using a multi-fiber spectrograph, we are able to collect high signal-to-noise, high resolution spectra of a sample of photometric candidate members.…

天体物理学 · 物理学 2009-10-31 D. Barrado y Navascues , Constantine P. Deliyannis , John R. Stauffer

New fibre spectroscopy and radial velocities from the WIYN telescope are used to measure photospheric lithium in 242 high-probability, zero-age-main-sequence (ZAMS) F- to K-type members of the rich cluster M35. Combining these with…

太阳与恒星天体物理 · 物理学 2020-10-21 R. D. Jeffries , R. J. Jackson , Qinghui Sun , Constantine P. Deliyannis

We have carried out a high resolution spectroscopic survey of the 220-250 Myr old cluster NGC 6475: our main purpose is to investigate Li evolution during the early stages of the Main Sequence. We have determined Li abundances for 33 late F…

天体物理学 · 物理学 2009-11-07 Paola Sestito , Sofia Randich , Jean-Claude Mermilliod , Roberto Pallavicini

We present lithium abundances for ~50 X-ray selected candidate members of the 30-50 Myr old open clusters IC 2602 and IC 2391. These data enlarge and extend to cooler temperatures previous Li surveys of these clusters by Stauffer et al.…

天体物理学 · 物理学 2009-11-06 S. Randich , R. Pallavicini , G. Meola , J. R. Stauffer , Suchitra C. Balachandran

We obtain lithium abundances for G and K stars in Blanco 1, an open cluster with an age similar to, or slightly younger than, the Pleiades. We critically examine previous spectroscopic abundance analyses of Blanco 1 and conclude that while…

天体物理学 · 物理学 2009-10-30 R. D. Jeffries , D. J. James

Hydra spectra of 85 G-K dwarfs in the young cluster, M35, near the Li 6708 Angstrom line region are analyzed. From velocities and Gaia astrometry, 78 are likely single-star members which, combined with previous work, produces 108 members…

太阳与恒星天体物理 · 物理学 2018-07-18 B. J. Anthony-Twarog , C. P. Deliyannis , D. Harmer , D. B. Lee-Brown , A. Steinhauer , Q. Sun , B. A. Twarog

We present spectroscopic observations of candidate F, G and K type stars in NGC 6633, an open cluster with a similar age to the Hyades. We identify 10 new cluster members including one short period binary system. Combining this survey with…

天体物理学 · 物理学 2009-11-07 R. D. Jeffries , E. J. Totten , S. Harmer , C. P. Deliyannis

Lithium abundances, radial velocities and rotational velocities are reported for 20 candidate F, G and K stars of the sparse Coma Berenices open cluster. All the stars are proper-motion selected, and our radial velocities support the…

天体物理学 · 物理学 2009-11-06 A. Ford , R. D. Jeffries , D. J. James , J. R. Barnes

Measurements of lithium (Li) abundances in open clusters provide a unique tool for following the evolution of this element with age, metallicity, and stellar mass. Using FLAMES/Giraffe on the VLT, we obtained spectra of 157 candidate…

太阳与恒星天体物理 · 物理学 2009-11-13 S. Randich , G. Pace , L. Pastori , A. Bragaglia

Context. As a fragile element, lithium is a sensitive probe of physical processes occurring in stellar interiors. Aims. We aim at investigating the relationship between lithium abundance and rotation rate in low-mass members of the newly…

太阳与恒星天体物理 · 物理学 2020-04-01 J. Arancibia-Silva , J. Bouvier , A. Bayo , P. A. B. Galli , W. Brandner , H. Bouy , D. Barrado

We have determined Li abundances for 11 G-type stars in the 6-8 Gyr old open cluster NGC 188. These data significantly enlarge the number of cluster stars with Li measurements, allowing us to extend the investigation of Li depletion in open…

天体物理学 · 物理学 2008-11-26 Sofia Randich , Paola Sestito , Roberto Pallavicini

We report discovery of significant depletion of Li on the surfaces of F dwarf stars in the 150-Myr-old open cluster M35, analagous to a feature in the 700-Myr-old Hyades cluster that has been referred to as the ``Li gap.'' We have caught…

天体物理学 · 物理学 2009-11-10 Aaron Steinhauer , Constantine P. Deliyannis

Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We…

太阳与恒星天体物理 · 物理学 2016-12-14 D. Barrado , H. Bouy , J. Bouvier , E. Moraux , L. M. Sarro , E. Bertin , J. C. Cuillandre , J. R. Stauffer , J. Lillo-Box , A. Pollock

The evolution of lithium abundance over a star's lifetime is indicative of transport processes operating in the stellar interior. We revisit the relationship between lithium content and rotation rate previously reported for cool dwarfs in…

太阳与恒星天体物理 · 物理学 2018-06-13 J. Bouvier , D. Barrado , E. Moraux , J. Stauffer , L. Rebull , L. Hillenbrand , A. Bayo , I. Boisse , H. Bouy , E. DiFolco , J. Lillo-Box , M. Morales Calderon

Li abundances are derived for a sample of bulgelike stars with isochronal ages of 10-11 Gyr. These stars have orbits with pericentric distances, Rp, as small as 2-3 kpc and Zmax < 1 kpc. The sample comprises G and K dwarf stars in the…

天体物理学 · 物理学 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon , Bruno Castilho

Our study is a follow-up of the SACY project, an extended survey in the Southern Hemisphere targeted to search for young nearby associations. Nine associations have either been newly identified, or had their member list better defined.…

太阳与恒星天体物理 · 物理学 2015-05-14 L. da Silva , C. A. O. Torres , R. de la Reza , G. R. Quast , C. H. F. Melo , M. Sterzik

There is evidence in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, that rotation plays a key role in the Lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be less Li-depleted…

太阳与恒星天体物理 · 物理学 2016-11-30 S. Messina , A. C. Lanzafame , G. A. Feiden , M. Millward , S. Desidera , A. Buccino , I. Curtis , E. Jofre' , P. Kehusmaa , B. J. Medhi , B. Monard , R. Petrucci

We have obtained high resolution spectra of $\sim$40 members of M35, determined the Lithium-T$_{\rm{eff}}$ morphology and the distribution of the rotational velocity for G and K stars, and compared them to those of the Pleiades and other…

天体物理学 · 物理学 2007-05-23 D. Barrado y Navascues , C. P. Deliyannis , J. R. Stauffer

Lithium abundances in open clusters are a very effective probe of mixing processes, and their study can help to understand the large depletion of lithium in the Sun. Due to its age and metallicity, the open cluster M67 is especially…

太阳与恒星天体物理 · 物理学 2015-06-04 Giancarlo Pace , Matthieu Castro , Jorge Melendez , Sylvie Theado , Jose-Dias do Nascimento

The prediction of the PLANCK-constrained primordial lithium abundance in the Universe is in discordance with the observed Li abundances in warm Population II dwarf and subgiant stars. Among the physically best motivated ideas, it has been…

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