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Related papers: A Main Sequence CH-star in the globular cluster M5…

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We present the homogeneous reanalysis of Mg and Al abundances from high resolution UVES/FLAMES spectra for 31 red giants in the globular cluster NGC 2808. We found a well defined Mg-Al anticorrelation reaching a regime of subsolar Mg…

Solar and Stellar Astrophysics · Physics 2015-06-23 Eugenio Carretta

M15 is a globular cluster with a known spread in neutron-capture elements. This paper presents abundances of neutron-capture elements for 62 stars in M15. Spectra were obtained with the Michigan/Magellan Fiber System (M2FS) spectrograph,…

Our work focuses on the understanding of the origin of CNO-anomalies, which have been detected in several Galactic globular clusters (GCs). This study is based on a homogeneous data set of hundreds of medium resolution spectra of stars in…

Astrophysics · Physics 2009-11-13 Andrea Kayser , Michael Hilker , Eva K. Grebel , Philip G. Willemsen

We derive homogeneous abundances of Fe, O, Na and alpha-elements from high resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M 54) and for 25 red giants in the surrounding nucleus of the Sagittarius (Sgr) dwarf galaxy. Our main…

Astrophysics of Galaxies · Physics 2015-05-18 E. Carretta , A. Bragaglia , R. G. Gratton , S. Lucatello , M. Bellazzini , G. Catanzaro , F. Leone , Y. Momany , G. Piotto , V. D'Orazi

AIMS. We present abundance analysis based on high resolution spectra of 105 isolated red giant branch (RGB) stars in the Galactic Globular Cluster NGC 6121 (M4). Our aim is to study its star population in the context of the multi-population…

Astrophysics · Physics 2009-11-13 A. F. Marino , S. Villanova , G. Piotto , A. P. Milone , Y. Momany , L. R. Bedin , A. M. Medling

[Abridged] Detailed chemical tagging of individual stellar populations in the Galactic globular cluster (GC) NGC 1851 is presented. Abundances are derived from FLAMES spectra for the largest sample of giants (124) ever analysed in this…

Solar and Stellar Astrophysics · Physics 2015-05-28 Eugenio Carretta , Sara Lucatello , Raffaele Gratton , A. Bragaglia , Valentina D'Orazi

The peculiar Galactic globular cluster $\omega$ Centauri (NGC 5139) has drawn attention for its unique features - such as a high stellar mass and a broad distribution of chemical elements - that have led to the hypothesis that it might be…

We present low resolution UV-blue spectroscopic observations of red giant stars in the globular cluster M53 ([Fe/H]=-1.84), obtained to study primordial abundance variations and deep mixing via the CN and CH absorption bands. The…

Astrophysics · Physics 2009-11-13 Sarah L. Martell , Graeme H. Smith , Michael M. Briley

We measured carbon abundances and the $^{12}\mathrm{C}/^{13}\mathrm{C}$ ratio in 31 giant branch stars with previous CN and CH band measurements that span -2.33 $<$ M$_{\rm V}$ $<$ 0.18 in the globular cluster M10 (NGC 6254). Abundances…

Solar and Stellar Astrophysics · Physics 2019-06-14 Z. G. Maas , J. M. Gerber , Alex Deibel , C. A. Pilachowski

MWC 560 and other peculiar symbiotic binary, CH Cyg, have been classified as the prototypes of the new subclass of symbiotic systems - propellers, with accretion onto a magnetic white dwarf being the source of activity. The companion of the…

Astrophysics · Physics 2007-05-23 Sylwia M. Frackowiak , Maciej Mikolajewski , Toma Tomov

Pseudo two-colour diagrams or Chromosome maps (ChM) indicate that NGC 2808 host five different stellar populations. The existing ChMs have been derived by the Hubble Space Telescope photometry, and comprise of stars in a small field of view…

High-resolution spectra of six core helium-burning `clump' stars and three giants in the open cluster M 67 have been obtained with the SOFIN spectrograph on the Nordic Optical Telescope to investigate abundances of up to 25 chemical…

Astrophysics · Physics 2007-05-23 G. Tautvaisiene , B. Edvardsson , I. Tuominen , I. Ilyin

By combining high-resolution HST and wide-field ground based observations, in ultraviolet and optical bands, we study the Blue Straggler Star (BSS) population of the low density galactic globular cluster M55 (NGC 6809) over its entire…

Astrophysics · Physics 2009-11-13 B. Lanzoni , E. Dalessandro , S. Perina , F. R. Ferraro , R. T. Rood , A. Sollima , -

Intermediate resolution spectra at the Ca II triplet have been obtained for 55 candidate red giants in the field of the globular cluster M22 with the VLT/FORS instrument. Spectra were also obtained for a number of red giants in standard…

Astrophysics of Galaxies · Physics 2014-11-20 G. S. Da Costa , E. V. Held , I. Saviane , M. Gullieuszik

Rotationally induced mixing with subsequent dredge-up of nucleosynthesized material is discussed as a second parameter of the horizontal branch morphology in globular clusters. CNO abundances have been proposed as tracers of the dredge up…

Astrophysics · Physics 2009-11-10 Daniel Harbeck , Graeme H. Smith , Eva K. Grebel

We present results from a study of 94 red giant stars in the globular cluster M53. We use low-resolution spectra to measure the strength of CN and CH features at $\sim$3800 and 4300 \r{A}, respectively. The strengths of these features are…

Solar and Stellar Astrophysics · Physics 2021-06-09 Jeffrey M. Gerber , Eileen D. Friel , Enrico Vesperini

We have carried out high-precision photometry on a large number of archival HST images of the Galactic globular cluster NGC 6752, to search for signs of multiple stellar populations. We find a broadened main sequence, and demonstrate that…

Solar and Stellar Astrophysics · Physics 2014-11-20 A. P. Milone , G. Piotto , I. R. King , L. R. Bedin , J. Anderson , A. F. Marino , Y. Momany , L. Malavolta , S. Villanova

The chemical composition of multiple populations in the massive globular cluster (GC) NGC~2808 is addressed with the homogeneous abundance re-analysis of 140 red giant branch (RGB) stars. UVES spectra for 31 stars and GIRAFFE spectra for…

Solar and Stellar Astrophysics · Physics 2015-09-23 Eugenio Carretta

We present carbon abundances of red giants in Milky Way globular clusters and dwarf spheroidal galaxies (dSphs). Our sample includes measurements of carbon abundances for 154 giants in the clusters NGC 2419, M68, and M15 and 398 giants in…

We have derived the absolute proper motion (PM) of the globular cluster M55 using a large set of CCD images collected with the du Pont telescope between 1997 and 2008. We find (PM_RA*cos(DEC), PM_DEC) = (-3.31 +/- 0.10, -9.14 +/- 0.15)…

Astrophysics of Galaxies · Physics 2015-05-27 K. Zloczewski , J. Kaluzny , I. B. Thompson