A triple main sequence in the globular cluster NGC 2808

@article{Piotto2007ATM,
  title={A triple main sequence in the globular cluster NGC 2808},
  author={Giampaolo Piotto and Luigi R. Bedin and Jay Barry Anderson and Ivan R. King and Santi Cassisi and Antonino P. Milone and Sandro Villanova and Adriano Pietrinferni and Alvio Renzini},
  journal={The Astrophysical Journal},
  year={2007},
  volume={661},
  pages={53-56}
}
Accurate photometry with HST's ACS shows that the main sequence (MS) of the globular cluster NGC 2808 splits into three separate branches. The three MS branches may be associated with the complexities of the cluster's horizontal branch and of its abundance distribution. We attribute the MS branches to successive rounds of star formation, with different helium abundances; we discuss possible sources of helium enrichment. Some other massive globulars also appear to have complex populations; we… 
The ACS Survey of Galactic Globular Clusters. III. The Double Subgiant Branch of NGC 1851
Photometry with the Hubble Space Telescope Advanced Camera for Surveys (HST ACS) reveals that the subgiant branch (SGB) of the globular cluster NGC 1851 splits into two well-defined branches. If the
A Double Main Sequence in the Globular Cluster NGC 6397
High-precision multi-band Hubble Space Telescope (HST) photometry reveals that the main sequence of the globular cluster NGC 6397 splits into two components, containing {approx}30% and {approx}70% of
Evidence for multiple populations in the massive globular cluster NGC 2419 from deep uVI LBT photometry
We present accurate wide-field uVI photometry of the remote and massive Galactic globular cluster NGC 2419, aimed at searching for the u-V color spread along the Red Giant Branch (RGB) that is
The peculiar horizontal branch of NGC 2808
We present an accurate analysis of the peculiar horizontal branch (HB) of the massive Galactic globular cluster NGC 2808, based on high-resolution far-UV and optical images of the central region of
Multiple Sequences of M-dwarfs in NGC 2808 and ω Centauri.
  • A. Milone
  • Physics
    Proceedings of the International Astronomical Union
  • 2012
Abstract The infrared channel of the Wide-Field Camera 3 on the Hubble Space Telescope revealed multiple main sequences of very low-mass stars in the globular clusters NGC 2808 and ω Cen. In this
A WFC3/HST View of the Three Stellar Populations in the Globular Cluster NGC 6752
Multi-band Hubble Space Telescope photometry reveals that the main sequence, sub-giant, and the red-giant branch of the globular cluster NGC 6752 splits into three main components in close analogy
Multiple stellar populations in Magellanic Cloud clusters - I. An ordinary feature for intermediate age globulars in the LMC?
Context. The discovery of multiple main sequences (MS) in the massive clusters NGC 2808 and Omega Centauri, along with multiple subgiant branches in NGC 1851 and NGC 6388 has challenged the long-held
MIXED POPULATIONS IN GLOBULAR CLUSTERS: ET TU, 47 TUC?
We exploit the large number of archival Hubble Space Telescope images of 47 Tuc to examine its subgiant branch (SGB) and main sequence (MS) for signs of multiple populations. In the cluster core, we
Multiplicity of main-sequence turn-offs in globular clusters
We present color-magnitude diagrams of globular clusters for models with self-enrichment and primordial enrichment. The models with self-enrichment turn out to have two or more main-sequence turn-off
STAR FORMATION HISTORIES OF GLOBULAR CLUSTERS WITH MULTIPLE POPULATIONS. I. ω CEN, M22, AND NGC 1851
There is increasing evidence that some massive globular clusters (GCs) host multiple stellar populations having different heavy element abundances enriched by supernovae. They usually accompany
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 22 REFERENCES
A Helium Spread among the Main-Sequence Stars in NGC 2808
We have made a detailed study of the color distribution of the main sequence of the globular cluster (GC) NGC 2808, based on new deep HST WFPC2 photometry of a field in the uncrowded outskirts of the
Peculiar Multimodality on the Horizontal Branch of the Globular Cluster NGC 2808
We present distributions of colors of stars along the horizontal branch (HB) of the globular cluster NGC 2808, from Hubble Space Telescope Wide Field Planetary Camera 2 imaging in B, V, and an
The Early Evolution of Globular Clusters: The Case of NGC 2808
Enhancement and spread of helium among globular cluster stars have been recently suggested as a way to explain the horizontal-branch blue tails in those clusters that show a primordial spread in the
NGC 6441: another indication of very high helium content in globular cluster stars
Context. The metal-rich bulge globular cluster NGC 6441 shows both a well-developed blue horizontal branch (Rich et al.), and a strong slope upward from the red clump to the blue of the RR Lyrae
Discovery of Extended Blue Horizontal Branches in Two Metal-rich Globular Clusters*
We have used WFPC2 to construct B, V color-magnitude diagrams of four metal-rich globular clusters, NGC 104 (47 Tuc), NGC 5927, NGC 6388, and NGC 6441. All four clusters have well populated red
The Chemical Evolution of Helium in Globular Clusters: Implications for the Self-Pollution Scenario
We investigate the suggestion that there are stellar populations in some globular clusters with enhanced helium (Y ~ 0.28-0.40) compared to the primordial value. We assume that a previous generation
The Second-Parameter Effect in Metal-Rich Globular Clusters
Recent Hubble Space Telescope observations have found that the horizontal branches (HBs) in the metal-rich globular clusters NGC 6388 and NGC 6441 slope upward with decreasing B-V. Such a slope is
Metallicities on the double main sequence of ω centauri imply large helium enhancement
Having shown in a recent paper that the main sequence of ? Centauri is split into two distinct branches, we now present spectroscopic results showing that the bluer sequence is less metal-poor. We
On the discrete nature of the red giant branch of ω Centauri
We report on the results of an extensive Very Large Telescope high-resolution imaging campaign of the central region of the giant globular cluster ω Centauri. More than 100000 stars have been
Newly Identified Star Clusters in M33. I. Integrated Photometry and Color-Magnitude Diagrams
We present integrated photometry and color-magnitude diagrams (CMDs) for 24 star clusters in M33, of which 12 were previously uncataloged. These results are based on Advanced Camera for Surveys
...
1
2
3
...