Navegação Ciências Exatas e da Terra por Autor "Ortolani, Sergio"

Resultados 21-40 de 84

    • FSR 584 : a new globular cluster in the galaxy? 

      Bica, Eduardo Luiz Damiani; Bonatto, Charles Jose; Ortolani, Sergio; Barbuy, Beatriz (2007) [Artigo de periódico]
      Aims. We investigate the nature of the recently catalogued star cluster candidate FSR 584, which is projected in the direction of the molecular cloud W 3 and may be the nearest globular cluster to the Sun. Methods. 2MASS ...

    • Further probing the nature of FSR 1767 

      Bonatto, Charles Jose; Bica, Eduardo Luiz Damiani; Ortolani, Sergio; Barbuy, Beatriz (2009) [Artigo de periódico]
      With Two-Micron All-Sky Survey (2MASS) photometry and proper motions, Bonatto et al. suggested that FSR 1767 is a globular cluster (GC), while with J and K NTT/ SOFI photometry Froebrich, Meusinger & Scholz concluded that ...

    • Gemini/Phoenix H-band analysis of the globular cluster AL 3 

      Barbuy, Beatriz; Ernandes, Heitor; Souza, Stefano O.; Razera, Roberta Ferreira; Moura, Tatiana; Meléndez, Jorge; Pérez Villegas, Maria de Los Angeles; Zoccali, Manuela; Minniti, Dante; Dias, Bruno Moreira de Souza; Ortolani, Sergio; Bica, Eduardo Luiz Damiani (2021) [Artigo de periódico]
      The globular cluster AL 3 is old and located in the inner bulge. Three individual stars were observed with the Phoenix spectrograph at the Gemini South telescope. The wavelength region contains prominent lines of CN, OH, ...

    • Gemini-Phoenix infrared high-resolution abundance analysis of five giants in the bulge globular cluster NGC 6553 

      Meléndez, Jorge; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani; Zoccali, Manuela; Ortolani, Sergio; Renzini, Alvio; Hill, Vanessa (2003) [Artigo de periódico]
      A detailed abundance analysis of 5 giants of the metal-rich bulge globular cluster NGC 6553 was carried out using high resolution infrared spectra in the H band, obtained at the Gemini-South 8m telescope. JK photometry ...

    • Globular clusters in the inner Galaxy classified from dynamical orbital criteria 

      Pérez Villegas, Maria de Los Angeles; Barbuy, Beatriz; Kerber, Leandro de Oliveira; Ortolani, Sergio; Souza, Stefano O.; Bica, Eduardo Luiz Damiani (2020) [Artigo de periódico]
      Globular clusters (GCs) are the most ancient stellar systems in the Milky Way. Therefore, they play a key role in the understanding of the early chemical and dynamical evolution of our Galaxy. Around 40 per cent of them ...

    • Globular clusters within five grade of the galactic center 

      Barbuy, Beatriz; Bica, Eduardo Luiz Damiani; Ortolani, Sergio (1998) [Artigo de periódico]
      In the recent years we have concentrated efforts to collect Colour-Magnitude Diagrams of the globular clusters projected in the central parts of the Galaxy. So far we were able to gather photometric data in the V, I and ...

    • Globular cluster system and Milky Way properties revisited 

      Bica, Eduardo Luiz Damiani; Bonatto, Charles Jose; Barbuy, Beatriz; Ortolani, Sergio (2006) [Artigo de periódico]
      Aims. Updated data of the 153 Galactic globular clusters are used to readdress fundamental parameters of the Milky Way, such as the distance of the Sun to the Galactic centre, the bulge and halo structural parameters, and ...

    • Halo intruders in the Galactic bulge revealed by HST and Gaia : the globular clusters Terzan 10 and Djorgovski 1 

      Ortolani, Sergio; Nardiello, Domenico; Pérez Villegas, Maria de Los Angeles; Bica, Eduardo Luiz Damiani; Barbuy, Beatriz (2019) [Artigo de periódico]
      Context. The low-latitude globular clusters Terzan 10 and Djorgovski 1 are projected in the Galactic bulge, in a Galactic region highly affected by extinction. A discrepancy of a factor of ∼2 exists in the literature in ...

    • High-metallicity effects in BVRI colour-magnitude diagrams : the globular cluster NGC 6553 

      Ortolani, Sergio; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani (1990) [Artigo de periódico]
      We present BVRI CCD-photometry of about 15000 stars in the possibly super-metal-rich globular cluster NGC 6553. The photometry extends to V = 21.5 reaching the cluster turn-off region. In the V vs. (V-I) diagram the red ...

    • High quality seeing V, I and Gunn z imaging of Terzan 4 : a blue horizontal branch bulge globular cluster 

      Ortolani, Sergio; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani (1997) [Artigo de periódico]
      We study the globular cluster Terzan 4 projected close to the Galactic center, by means of V, I and Gunn z Colour-Magnitude Diagrams. The images were obtained under exceptional seeing conditions (0.35" - 0.55") at the ESO ...

    • High-resolution abundance analysis of four red giants in the globular cluster NGC 6558 

      Barbuy, Beatriz; Muniz, Leone V.; Ortolani, Sergio; Ernandes, Heitor; Dias, Bruno Moreira de Souza; Saviane, Ivo; Kerber, Leandro de Oliveira; Bica, Eduardo Luiz Damiani; Pérez Villegas, Maria de Los Angeles; Rossi, Luca James; Held, Enrico V. (2018) [Artigo de periódico]
      Context. NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H] ≈ −1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. ...

    • High-resolution abundance analysis of red giants in the globular cluster NGC 6522 

      Barbuy, Beatriz; Chiappini, C.C.M.; Cantelli, Elvis William Carvalho; Depagne, Éric; Pignatari, Marco; Hirschi, Raphael; Cescutti, Gabriele; Ortolani, Sergio; Hill, Vanessa; Zoccali, Manuela; Minniti, Dante; Trevisan, Marina; Bica, Eduardo Luiz Damiani; Gómez, Ana (2014) [Artigo de periódico]
      Context. The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522 have been interpreted as evidence ...

    • High-resolution abundance analysis of red giants in the metal-poor bulge globular cluster HP 1 

      Barbuy, Beatriz; Cantelli, Elvis William Carvalho; Vemado, Artur; Ernandes, Heitor; Ortolani, Sergio; Saviane, Ivo; Bica, Eduardo Luiz Damiani; Minniti, Dante; Dias, Bruno Moreira de Souza; Momany, Yazan; Hill, Vanessa; Zoccali, Manuela; Mello Junior, Cesar Henrique Siqueira (2016) [Artigo de periódico]
      Context. The globular cluster HP 1 is projected at only 3 :33 from the Galactic center. Together with its distance, this makes it one of the most central globular clusters in the Milky Way. It has a blue horizontal branch ...

    • High-resolution abundance analysis of two individual stars of the bulge globular cluster NCG 6553 

      Barbuy, Beatriz; Renzini, Alvio; Ortolani, Sergio; Bica, Eduardo Luiz Damiani; Guarnieri, M.D. (1999) [Artigo de periódico]
      A detailed abundance analysis of 2 giants of the metal-rich bulge globular cluster NGC6553 was carried out using high resolution échelle spectra obtained at the ESO 3.6m telescope. The temperature calibration of metal-rich ...

    • Hp 1 : a blue horizontal branch globular cluster in the bulge 

      Ortolani, Sergio; Bica, Eduardo Luiz Damiani; Barbuy, Beatriz (1997) [Artigo de periódico]
      We present V, I colour-magnitude diagrams of the globular cluster HP 1 obtained at the European Southern Observatory New Technology Telescope under exceptional seeing conditions. The cluster shows blue horizontal branch ...

    • HST NICMOS photometry of the reddened bulge globular clusters NGC 6528, Terzan 5, Liller 1, UKS 1 and Terzan 4 

      Ortolani, Sergio; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani; Renzini, Alvio; Zoccali, Manuela; Rich, Robert Michael; Cassisi, Santi (2001) [Artigo de periódico]
      We present results from NICMOS Hubble Space Telescope observations of the reddened bulge globular clusters NGC 6528, Terzan 5, Liller 1, UKS 1 and Terzan 4, obtained through the filters F110W (1.1 μm) and F160W (1.6 μm) ...

    • HST observations of Terzan 1 : a second parameter globular cluster in the galactic bulge 

      Ortolani, Sergio; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani; Renzini, Alvio; Marconi, Gianni; Gilmozzi, Roberto (1999) [Artigo de periódico]
      Hubble Space Telescope observations in the F555W and F814W bands are presented of the bulge globular cluster Terzan 1. This highly obscured cluster has the smallest projected distance to the Galactic center among all known ...

    • Infrared array photometry of bulge globular clusters I. Combined ground based JK and HST VI photometry of NGC 6553 

      Guarnieri, M.D.; Ortolani, Sergio; Montegriffo, P.; Renzini, Alvio; Barbuy, Beatriz; Bica, Eduardo Luiz Damiani; Moneti, Andrea (1998) [Artigo de periódico]
      JK infrared photometry for the bulge globular cluster NGC 6553, combined with high resolution visual VI observations are presented and discussed in connection with the bulge metal rich population. The infrared data were ...

    • Kronberger 49 : a new low-mass globular cluster or an unprecedented bulge window 

      Ortolani, Sergio; Bonatto, Charles Jose; Bica, Eduardo Luiz Damiani; Barbuy, Beatriz; Saito, Roberto K. (2012) [Artigo de periódico]
      We employ optical and near-infrared photometry to study the stars in the direction of the star cluster candidate Kronberger 49. The optical color–magnitude diagrams (V, I, and Gunn z photometry obtained with the Galileo ...

    • Lynga 7 : a new disk globular cluster? 

      Ortolani, Sergio; Bica, Eduardo Luiz Damiani; Barbuy, Beatriz (1993) [Artigo de periódico]
      We have observed Lyngå 7, previously catalogued as an open cluster, in B, V and I.The Colour Magnitude Diagrams (CMDs) show that it is old like a globular cluster, or an extremely old thick/old disk cluster. It has a red ...