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Related papers: The Mg-K anti-correlation in Omega Centauri

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In this study, we report the results of Fe, Mg, Al, and Si abundances analysis for a sample of 439 stars in Omega Centauri, using high-resolution spectra obtained with the VLT/FLAMES multi-object spectrograph. Our analysis reveals the…

Solar and Stellar Astrophysics · Physics 2024-01-10 Deimer Antonio Alvarez Garay , Alessio Mucciarelli , Michele Bellazzini , Carmela Lardo , Paolo Ventura

Omega Centauri is no longer the only globular cluster known to contain multiple stellar populations, yet it remains the most puzzling. Due to the extreme way in which the multiple stellar population phenomenon manifests in this cluster, it…

We derive abundances of Fe, Na, O, and s-elements from GIRAFFE@VLT spectra for more than 200 red giant stars in the Milky Way satellite Omega Centauri. Our preliminary results are that: (i) we confirm that Omega Centauri exibiths large…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. F. Marino , G. Piotto , R. Gratton , A. P. Milone , M. Zoccali , L. R. Bedin , S. Villanova , A. Bellini

We derive [K/Fe] abundance ratios for 119 stars in the globular cluster NGC 2808, all of them having O, Na, Mg and Al abundances homogeneously measured in previous works. We detect an intrinsic star-to-star spread in the Potassium…

Solar and Stellar Astrophysics · Physics 2015-06-23 A. Mucciarelli , M. Bellazzini , T. Merle , B. Plez , E. Dalessandro , R. Ibata

Recent wide-field photometric surveys (Lee et al.; Pancino et al.) have shown the existence of a previously unknown metal-rich ([Fe/H] -0.6) stellar population in the galactic globular cluster omega Centauri. The discovery of this new…

Astrophysics · Physics 2009-11-07 F. R. Ferraro , M. Bellazzini , E. Pancino

We derive [Cu/Fe] for 117 giant stars in ten globular clusters (M3, M4, M5, M10, M13, M15, M71, NGC 7006, NCG 288, and NGC 362) and find that globular cluster Cu abundances appear to follow [Cu/Fe] trends found in the field. This result is…

We present abundances of several light, alpha, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri. Our observations lie in the range 12.0<V<13.5 and focus on the…

Solar and Stellar Astrophysics · Physics 2011-02-11 Christian I. Johnson , Catherine A. Pilachowski , R. Michael Rich , Jon P. Fulbright

We present a chemical-composition analysis of 77 red-giant stars in Omega Centauri. We have measured abundances for carbon and nitrogen, and combined our results with abundances of O, Na, La, and Fe that we determined in our previous work.…

Solar and Stellar Astrophysics · Physics 2015-06-03 A. F. Marino , A. P. Milone , G. Piotto , S. Cassisi , F. D'Antona , J. Anderson , A. Aparicio , L. R. Bedin , A. Renzini , S. Villanova

We present manganese abundances in 10 red-giant members of the globular cluster Omega Centauri; 8 stars are from the most metal-poor population (RGB MP and RGB MInt1) while two targets are members of the more metal rich groups (RGB MInt2…

Astrophysics of Galaxies · Physics 2015-05-19 Katia Cunha , Verne V. Smith , Maria Bergemann , Nicholas B. Suntzeff , David L. Lambert

We present elemental abundances for 855 red giant branch (RGB) stars in the globular cluster Omega Centauri (w Cen) from spectra obtained with the Blanco 4m telescope and Hydra multifiber spectrograph. The sample includes nearly all RGB…

Solar and Stellar Astrophysics · Physics 2015-05-19 Christian I. Johnson , Catherine A. Pilachowski

In this work we derived [K/Fe] and [Mg/Fe] abundance ratios for six stars of the old globular cluster NGC 1786 in the Large Magellanic Cloud. We employed high-resolution spectra acquired with the MIKE spectrograph mounted at the…

Solar and Stellar Astrophysics · Physics 2025-10-06 Deimer Antonio Alvarez Garay , Alessio Mucciarelli , Lorenzo Monaco

We present spectroscopic abundances and radial velocities for giant stars in the Galactic globular cluster omega Centauri based on the CaII infrared triplet. Two samples of stars were observed: 234 stars at M_V = 1.25 on the lower giant…

Astrophysics · Physics 2009-10-05 Nicholas B. Suntzeff , Robert P. Kraft

We present radial velocities, Fe, and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri ($\omega$ Cen). The majority of our data lie in the range 11.0$<$V$<$13.5, which covers the RGB from…

We have determined stellar parameters and abundances for 221 giant branch stars in the globular cluster {\omega} Centauri. A combination of photometry and lower-resolution spectroscopy was used to determine temperature, gravity,…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jeffrey D. Simpson , P. L. Cottrell , C. C. Worley

Using the 2dF multi-fibre instrument on the AAT, moderate resolution spectra have been obtained for a large sample of stars on the main sequence and at the turnoff in the unusual globular cluster omega Centauri. We investigate the behaviour…

Astrophysics · Physics 2009-11-11 G. S. Da Costa , Laura Stanford , John E. Norris , R. D. Cannon

We model the evolution of manganese relative to iron in the progenitor system of the globular cluster Omega Centauri by means of a self-consistent chemical evolution model. We use stellar yields that already reproduce the measurements of…

Astrophysics of Galaxies · Physics 2015-05-28 Donatella Romano , Gabriele Cescutti , Francesca Matteucci

Abundance ratios of carbon, nitrogen and strontium relative to iron, calculated using spectrum synthesis techniques, are given for a sample of main sequence and turnoff stars that belong to the globular cluster omega Centauri. The…

Astrophysics · Physics 2009-11-13 Laura M. Stanford , G. S. Da Costa , John E. Norris

The globular cluster $\omega$ Centauri (NGC 5139) is a puzzling stellar system harboring several distinct stellar populations whose origin still represents a unique astrophysical challenge. Current scenarios range from primordial chemical…

Astrophysics of Galaxies · Physics 2014-11-20 Sandro Villanova , Giovanni Carraro , Riccardo Scarpa , Gianni Marconi

In the complex picture of multiple stellar populations in globular clusters (GCs), a special role is played by NGC 5139 Omega Centauri. At variance with the majority of GCs, Omega Cen exhibits significant star-to-star variations in…

Medium resolution spectra of more than 400 subgiant and turn-off region stars in Omega Centauri were analysed. The observations were performed at the VLT/Paranal with FORS2/MXU. In order to determine the metallicities of the sample stars,…

Astrophysics · Physics 2007-05-23 Andrea Kayser , Michael Hilker , Tom Richtler , Philip G. Willemsen
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