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相关论文: Emergence of a lithium dip in ~35 Myr "Snake" Open…

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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

We consider WIYN/Hydra spectra of 329 photometric candidate members of the 420-Myr-old open cluster M48, and report Lithium detections or upper limits for 234 members and likely members. The 171 single members define a number of notable…

太阳与恒星天体物理 · 物理学 2023-07-26 Qinghui Sun , Constantine P. Deliyannis , Aaron Steinhauer , Barbara J. Anthony-Twarog , Bruce A. Twarog

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 determine the surface lithium abundance of the eclipsing binary components in V 505 Per (HIP 10961), A(Li)=2.65+/-0.07 and 2.35+/-0.1, which supports the rather unexpected conclusion that their surface Li abundances differ. We find…

太阳与恒星天体物理 · 物理学 2025-07-29 G. Koenigsberger , W. Schmutz , C. Pilachowski , A. R. Mejia-Nava , D. Sikorski , M. Cordero

Lithium (Li) abundance is an age indicator for G, K, and M stellar types, as its abundance decreases over time for these spectral types. However, despite the observational efforts made over the past few decades, the role of rotation,…

太阳与恒星天体物理 · 物理学 2024-05-15 D. Cuenda-Muñoz , D. Barrado , M. A. Agüeros , J. L. Curtis , H. Bouy

We present a survey of lithium abundances in 185 main- sequence field stars with Teff between 5600 and 6600 K and [Fe/H] from -1.4 to +0.2 based on high-resolution spectra of 130 stars and a reanalysis of data from Lambert et al. (1991).…

天体物理学 · 物理学 2009-11-06 Y. Q. Chen , P. E. Nissen , T. Benoni , G. Zhao

We present the results of a photometric and spectroscopic survey of cool M dwarf candidates in the young open cluster NGC 2547. Using the 2dF fiber spectrograph, we have searched for the luminosity at which lithium remains unburned in an…

We investigate two topics regarding solar mass FGK-type stars, the lithium rotation connection (LRC) and the existence of the "lithium desert". We determine the minimum critical rotation velocity ($v \sin i$) related with the LRC separating…

太阳与恒星天体物理 · 物理学 2021-10-27 F. Llorente de Andrés , C. Chavero , R. de la Reza , S. Roca-Fàbrega , C. Cifuentes

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

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

Context: Knowledge of the age distribution of stars in young clusters and associations is crucial to constrain models of star formation. HR diagrams of different young clusters and associations suggest the presence of age spreads, but the…

天体物理学 · 物理学 2009-11-11 G. G. Sacco , S. Randich , E. Franciosini , R. Pallavicini , F. Palla

We have obtained new photometry and intermediate resolution ($\Delta \lambda = 2.7$ \AA\ ) spectra of 19 of these objects (14.9 $\le$ $I_c$ $\le$ 17.5) in order to confirm cluster membership. We identify 15 of our targets as likely cluster…

天体物理学 · 物理学 2011-02-11 D. Barrado y Navascues , J. R. Stauffer , B. M. Patten

We investigate here the lithium content of young low-mass stars in the 5~Myr-old star forming region NGC~2264 and its relationship with rotation. We combine lithium equivalent width measurements, EW(Li), from the Gaia-ESO Survey with the…

We present lithium abundances for 119 main-sequence stars in the old open cluster NGC 188 (age = 6.3 Gyr), using high-resolution, high signal-to-noise ratio spectra from WIYN/Hydra. We observe the stars over multiple nights and measure…

太阳与恒星天体物理 · 物理学 2025-09-19 Qinghui Sun , Constantine P. Deliyannis , Bruce A. Twarog , Barbara J. Anthony-Twarog

The lithium-dip observed in mid-F dwarfs remains a long-standing challenge for stellar evolution models. We present high-precision stellar parameters and A(Li) for 22 new comoving pairs, primarily located on the hotter side of the Li-Dip.…

太阳与恒星天体物理 · 物理学 2025-08-14 Qinghui Sun , Yuan-Sen Ting , Barbara J. Anthony-Twarog , Bruce A. Twarog , Fan Liu , Yuxi , Lu

Determination of the lithium depletion boundary (LDB), i.e., the observational limit below which the cores of very low-mass objects do not reach high enough temperature for Li destruction, has been used to obtain ages for several open…

太阳与恒星天体物理 · 物理学 2018-04-04 Eduardo L. Martín , Nicolas Lodieu , Yakiv Pavlenko , Víctor J. S. Béjar

High-dispersion spectra centered on the Li 6708 A line have been obtained for 70 potential members of the open cluster NGC 3680, with an emphasis on stars in the turnoff region. A measurable Li abundance has been derived for 53 stars, 39 of…

太阳与恒星天体物理 · 物理学 2015-05-13 B. J. Anthony-Twarog , C. P. Deliyannis , B. A. Twarog , K. V. Croxall , J. D. Cummings

We report the evidence that several low-mass stars (<~0.4 Msun) of the Orion and Upper Scorpius clusters have lithium abundances well below the interstellar value. Due to time-dependent depletion, our result implies stellar ages greater…

天体物理学 · 物理学 2015-11-11 Francesco Palla , Sofia Randich

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 identified a large number of possible very low mass members of the cluster IC2391 based primarily on their location in an I versus (R-I)_C CM diagram. We have obtained new photometry and low resolution ($\Delta \lambda = 2.7$ \AA)…

天体物理学 · 物理学 2007-05-23 D. Barrado y Navascues , J. R. Stauffer , B. M. Patten
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