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Related papers: The anomalous Galactic globular cluster NGC 2808

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We present new UV (F218W) data for stars in the central region of the Galactic globular cluster NGC2808, collected with the WFPC2 camera on board of the Hubble Space Telescope. These data together with F439W and F555W-band data and previous…

Astrophysics · Physics 2009-11-11 V. Castellani , G. Iannicola , G. Bono , M. Zoccali , S. Cassisi , R. Buonanno

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 the cluster obtained with HST. We confirm…

Solar and Stellar Astrophysics · Physics 2015-05-19 E. Dalessandro , M. Salaris , F. R. Ferraro , S. Cassisi , B. Lanzoni , R. T. Rood , F. Fusi Pecci , E. Sabbi

In this study, we identified and characterized the hot and luminous UV-bright stars in the globular cluster NGC 2808. We combined data from the Ultra Violet Imaging Telescope (UVIT) on-board the Indian space satellite, AstroSat, with the…

Solar and Stellar Astrophysics · Physics 2021-02-24 Deepthi S. Prabhu , Annapurni Subramaniam , Snehalata Sahu

We present distributions of colors of stars along the horizontal branch of the globular cluster NGC 2808, from Hubble Space Telescope WFPC2 imaging in B, V, and an ultraviolet filter (F218W). This cluster's HB is already known to be…

Globular clusters represent stellar laboratories where observations can be used to validate models of stellar evolution. In this study, we put forth new ultraviolet (UV) photometric results of stars in the Galactic globular cluster NGC…

Solar and Stellar Astrophysics · Physics 2019-03-06 Rashi Jain , S. Vig , S. K. Ghosh

A recent study of hot (20,000 to 30,000 K) extreme horizontal branch (EHB) stars in globular clusters (GCs) has led to the discovery of their variability. It is suggested that this variability is driven by the projected rotation of magnetic…

Solar and Stellar Astrophysics · Physics 2021-09-15 Deepthi S. Prabhu , Annapurni Subramaniam , Snehalata Sahu

We present observations of the center of the Galactic globular cluster NGC 6273, obtained with the HST/WFPC2 camera as part of the snapshot program GO-7470. A B, V color-magnitude diagram (CMD) for ~28,000 stars is presented and discussed.…

Astrophysics · Physics 2009-10-31 G. Piotto , M. Zoccali , I. R. King , S. G. Djorgovski C. Sosin , R. M. Rich , G. Meylan

We present accurate new ultraviolet and optical BVI photometry for the Galactic globular cluster ngc2808, based on both ground-based and archival HST imagery. From this we have selected a sample of ~2,000 HB stars; given the extensive…

BV CCD photometry of the central (1.5 arcmin x 2.0 arcmin) part of the mildly concentrated outer-halo globular cluster NGC 6229 is presented. The data reduction in such a crowded field was based on a wavelet transform analysis. Our larger…

Astrophysics · Physics 2016-08-30 J. Borissova , M. Catelan , N. Spassova , A. V. Sweigart

We present a deep color magnitude diagram for the galactic globular cluster NGC 2808 (C0911-646), reaching 3 magnitudes below the main sequence turnoff. A set of local photometric standards are provided, and the mean cluster reddening and…

Astrophysics · Physics 2009-10-31 Alistair R. Walker

The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of…

In this study we present first results from multi-wavelength Hubble Space Telescope (HST) observations of the Galactic globular cluster GC NGC2808 as an extension of the Hubble Space Telescope UV Legacy Survey of Galactic GCs (GO-13297 and…

Solar and Stellar Astrophysics · Physics 2015-08-06 A. P. Milone , A. F. Marino , G. Piotto , A. Renzini , L. R. Bedin , J. Anderson , S. Cassisi , F. D'Antona , A. Bellini , H. Jerjen , A. Pietrinferni , P. Ventura

We present a study of Far Ultraviolet (FUV) bright horizontal branch (HB) stars to understand the peculiarities seen in the HB sequence of the Globular Cluster NGC 1851, using ground and space based multi-wavelength data. Optical and UV…

Solar and Stellar Astrophysics · Physics 2020-12-16 Gaurav Singh , Snehalata Sahu , Annapurni Subramaniam , R. K. S. Yadav

We present an analysis of optical and ultraviolet Hubble Space Telescope photometry for evolved stars in the core of the distant massive globular cluster NGC 2419. We characterize the horizontal branch (HB) population in detail including…

Astrophysics · Physics 2009-11-13 Eric L. Sandquist , Jordan M. Hess

We present the broadest and most precise empirical investigation of red giant branch bump (RGBB) brightness and number counts ever conducted. We implement a new method and use data from two \textit{Hubble Space Telescope (HST)} globular…

Astrophysics of Galaxies · Physics 2015-05-30 David M. Nataf , Andrew P. Gould , Marc H. Pinsonneault , Andrzej Udalski

We present high resolution UVES+VLT spectroscopic observations of 61 stars in the extended blue horizontal branches of the Galactic globular clusters NGC 1904 (M79), NGC 2808, NGC 6093 (M80), and NGC 7078 M15). Our data reveal for the first…

Astrophysics · Physics 2007-05-23 A. Recio-Blanco , G. Piotto , A. Aparicio , A. Renzini

A catalog including a set of the most recent Color Magnitude Diagrams (CMDs) is presented for a sample of 61 Galactic Globular Clusters (GGCs). We used this data-base to perform an homogeneous systematic analysis of the evolved sequences…

Astrophysics · Physics 2010-02-18 F. R. Ferraro , M. Messineo , F. Fusi Pecci , M. A. De Palo , O. Straniero , A. Chieffi , M. Limongi

The outer-halo globular cluster NGC 6229 has a peculiar horizontal-branch (HB) morphology, with clear indications of a bimodal HB and a ``gap" on the blue HB. In this paper, we present extensive synthetic HB simulations to determine whether…

Astrophysics · Physics 2009-10-30 M. Catelan , J. Borissova , A. V. Sweigart , N. Spassova

We study the white dwarf (WD) cooling sequence of the Galactic Globular Cluster (GGC) NGC 2808 by using deep near-UV data from the Hubble Space Telescope and theoretical models, to investigate if this cluster hosts an excess of WDs. Excess…

Solar and Stellar Astrophysics · Physics 2025-10-06 Laksh Gupta , Samyaday Choudhury , Annalisa Calamida , Christian I. Johnson , Domenico Nardiello

In this paper we present preliminary results from our HST project aimed at exploring the connection between the stellar dynamics and stellar evolution in the cores of high-density globular clusters. We illustrate the discovery of horizontal…

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