English
Related papers

Related papers: Lithium depleted stars in the young sigma Ori clus…

200 papers

We present Li abundances for 14 solar-type stars in the intermediate age (~ 2 Gyr) clusters IC 4651 and NGC 3680. The log n(Li) vs. effective temperature distributions are compared with those of the similar age cluster NGC 752, of the…

Astrophysics · Physics 2007-05-23 S. Randich , L. Pasquini , R. Pallavicini

With the purpose of performing a homogeneous determination of elemental abundances for members of the Lupus T association, we analyzed three chemical elements: lithium, iron, and barium. The aims were: to derive the Li abundance for ~90% of…

Solar and Stellar Astrophysics · Physics 2017-09-13 K. Biazzo , A. Frasca , J. M. Alcalá , M. Zusi , E. Covino , S. Randich , M. Esposito , C. F. Manara , S. Antoniucci , B. Nisini , E. Rigliaco , F. Getman

The lithium present in the photospheres of solar-type stars is transported to the inner parts by convection, reaching regions even somewhat below the convection zone, by non-standard transport mechanisms. In stars with deeper convective…

Solar and Stellar Astrophysics · Physics 2023-05-04 Giulia Martos , Jorge Meléndez , Anne Rathsam , Gabriela Carvalho Silva

We analyse multi-wavelength observations of 32 young star clusters and associations in M33 with known oxygen abundance (8 < 12 + log(O/H) < 8.7), using ultraviolet (UV), optical, mid-infrared (MIR), CO (1-0) and 21-cm line (HI)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 M. Grossi , E. Corbelli , C. Giovanardi , L. Magrini

We present new K- and L'-band imaging of a representative sample of members of the young 3-5 Myr old sigma Orionis cluster. We identified objects with (K-L') excess by analysing colour-colour diagrams and comparing the observations with…

Astrophysics · Physics 2009-11-10 J. M. Oliveira , R. D. Jeffries , J. Th. van Loon

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…

Solar and Stellar Astrophysics · Physics 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 present the results of a spectroscopic survey of X-ray selected, low-mass candidate members of the young open cluster NGC 2547. Using a combination of photometry, spectroscopic indices and radial velocities we refine our candidate list…

Astrophysics · Physics 2009-11-07 R. D Jeffries , J. M. Oliveira , D. Barrado y Navascues , J. R. Stauffer

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).…

Astrophysics · Physics 2009-11-06 Y. Q. Chen , P. E. Nissen , T. Benoni , G. Zhao

We have performed a deep multi-band photometric analysis of the star cluster population of Haro 11. This starburst galaxy (log L_FUV = 10.3 L_sun) is considered a nearby analogue of Lyman break galaxies (LBGs) at high redshift. The study of…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-24 Angela Adamo , Göran Östlin , Erik Zackrisson , Matthew Hayes

In the Gaia era, the majority of stars in the Solar neighbourhood have parallaxes and proper motions precisely determined while spectroscopic age indicators are still missing for a large fraction of low-mass young stars. In this work we…

The main goal of this work is to evaluate the correlation between Li abundance, age, and mass. Using high-quality ESO/HARPS data (R $\simeq$ 115 000; 270 $\leq$ SNR $\leq$ 1000), we measured Li abundances via spectral synthesis of the…

Solar and Stellar Astrophysics · Physics 2023-09-15 Anne Rathsam , Jorge Meléndez , Gabriela Carvalho Silva

Lithium abundances are presented and discussed for 70 members of the 50 Myr old open cluster alpha Per. More than half of the abundances are from new high-resolution spectra. The Li abundance in the F-type stars is equal to its presumed…

Solar and Stellar Astrophysics · Physics 2015-05-19 Suchitra C. Balachandran , Sushma V. Mallik , David L. Lambert

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…

Solar and Stellar Astrophysics · Physics 2025-09-19 Qinghui Sun , Constantine P. Deliyannis , Bruce A. Twarog , Barbara J. Anthony-Twarog

Accurate measurements of lithium abundances in young low-mass stars provide an independent and reliable age diagnostics. Previous studies of nearby star forming regions have identified significant numbers of Li-depleted stars,often at…

Astrophysics · Physics 2009-11-13 P. Sestito , F. Palla , S. Randich

We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to map the age distribution of the stellar population in the inner 400 pc of the Seyfert 2 galaxy Mrk 1157 (NGC 591), at a spatial resolution of 35 pc. We have…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Rogério Riffel , Rogemar André Riffel , Fabricio Ferrari , Thaisa Storchi-Bergmann

The 32 Orionis group was discovered almost a decade ago and despite the fact that it represents the first northern, young (age ~ 25 Myr) stellar aggregate within 100 pc of the Sun ($d \simeq 93$ pc), a comprehensive survey for members and…

Solar and Stellar Astrophysics · Physics 2017-04-12 Cameron P. M. Bell , Simon J. Murphy , Eric E. Mamajek

The young $\sigma$-Orionis cluster is an important location for understanding the formation and evolution of stars, brown dwarfs, and planetary-mass objects. Its metallicity, although being a fundamental parameter, has not been well…

As part of a long term effort to understand pre-main sequence Li burning, we have obtained high resolution spectroscopic observations of 14 late type stars (G0--M1) in the young open cluster IC~4665. Most of the stars have \ha filled-in and…

Astrophysics · Physics 2016-08-30 E. L. Martin , D. Montes

We report the discovery of a lithium dip (Li-dip) in the stellar "Snake" (age = $35 \pm 5$ Myr), challenging the classical view that Li-dips emerge only at ages $\gtrsim 150$ Myr. Using high-resolution spectra from GALAH DR4 ($R \sim…

Solar and Stellar Astrophysics · Physics 2026-02-10 Yun-Yi Zhang , Hai-Jun Tian , Jian-Rong Shi , Cheng-Cheng Xie , Xiang-Ming Yang

We present results of age determination based on the standard procedure of isochrone fitting for about 600 star clusters younger than about 1.2 Gyr from the central parts of the LMC. Comparison of age distributions of star clusters from the…

Astrophysics · Physics 2007-05-23 G. Pietrzynski , A. Udalski