Hot Stars in Globular Cluster - A Spectroscopist's View

Abstract

Globular clusters are ideal laboratories to study the evolution of low-mass stars. In this work we concentrate on three types of hot stars observed in globular clusters: horizontal branch stars, UV bright stars, and white dwarfs. After providing some historical background and information on gaps and blue tails we discuss extensively hot horizontal branch stars in metal-poor globular clusters, esp. their abundance anomalies and the consequences for the determination of their atmospheric parameters and evolutionary status. Hot horizontal branch stars in metal-rich globular clusters are found to form a small, but rather inhomogeneous group that cannot be explained by one evolutionary scenario. Hot UV bright stars show a lack of classic post-AGB stars that may explain the lack of planetary nebulae in globular clusters. Finally we discuss first results of spectroscopic observations of white dwarfs in globular clusters.

20 pages, 4 figures (fully resolved PS file of Fig. 1 available at http://a400.sternwarte.uni-erlangen.de/ftp/MOEHLER/ASTRO-PH/FIG1.PS) Invited Review, to appear in the October 2001 issue of PASP

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Cited by in corpus (52)

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• The High Velocity Gas toward Messier 5: Tracing Feedback Flows in the Inner Galaxy
• UV Properties of Galactic Globular Clusters with GALEX I. The Color-Magnitude Diagrams
• The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. VII. Implications from the Nearly Universal Nature of Horizontal Branch Discontinuities
• HVS7: a chemically peculiar hyper-velocity star
• Evolutionary modelling of subdwarf B stars using MESA with the predictive mixing and convective premixing schemes
• Ionized Gas in the First 10 kpc of the Interstellar Galactic Halo
• Spectroscopy of horizontal branch stars in NGC6752 - Anomalous results on atmospheric parameters and masses
• The Swift UVOT Stars Survey: I. Methods and Test Clusters
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• The Na-O anticorrelation in horizontal branch stars. IV. M22
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• The s-Process Enrichment of the Globular Clusters M4 and M22
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• Clean catalogues of blue horizontal-branch stars using Gaia EDR3
• Characterization of hot populations of Melotte 66 open cluster using Swift/UVOT
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• High Resolution Optical Spectroscopy of a Newly Discovered Post-AGB Star with a Surprising Metallicity in the Globular Cluster M79
• Peculiarities in the horizontal branch stars of globular cluster NGC 1851: Discovery of a Blue straggler companion to an EHB star
• The iron abundance of the Magellanic Bridge
• Hot horizontal branch stars in NGC 288 - effects of diffusion and stratification on their atmospheric parameters
• A search for magnetic fields in cool sdB stars
• The First Extensive Exploration of UV-bright Stars in the Globular Cluster NGC 2808
• SHOTGLAS II. MUSE spectroscopy of blue horizontal branch stars in the core of $\omega$ Centauri and NGC 6752
• EVR-CB-004: An Inflated Hot Subdwarf O star + Unseen WD Companion in a Compact Binary Discovered with the Evryscope
• Investigation of the Globular Cluster NGC 2808 with the Ultra-Violet Imaging Telescope
• The ultraviolet colour of globular clusters in M31: a core density effect?
• A Census of Above-Horizontal-Branch Stars in Galactic Globular Clusters
• Hubble Space Telescope imaging of the extremely metal-poor globular cluster EXT8 in Messier 31
• UVMag: stellar formation, evolution, structure and environment with space UV and visible spectropolarimetry
• Hubble Space Telescope FUV observations of M31's globular clusters suggest a spatially homogeneous helium-enriched sub population
• Astrometric Membership Tests for the Zinn-Newell-Gibson "UV-Bright" Stars in Galactic Globular Clusters
• A Grid of Synthetic Spectra for Subdwarfs: Non-LTE line-blanketed atmosphere models
• Globular Cluster UVIT legacy Survey (GlobUleS) III. Omega Centauri in Far-Ultraviolet
• The binary fraction of Blue Horizontal-Branch (BHB) Stars
• Study of UV bright stellar populations in the globular cluster NGC 1261 using AstroSat
• Globular clusters as laboratories for stellar evolution
• A non-LTE abundance analysis of the post-AGB star ROA 5701
• Observations of the Hot Horizontal-Branch Stars in the Metal-Rich Bulge Globular Cluster NGC 6388 - Indications of Helium Enrichment and a Lesson in Crowded Field Spectroscopy
• Stellar populations of the globular cluster NGC 5053 investigated using AstroSat-Ultra Violet Imaging Telescope
• Old stellar systems in UV: resolved and integrated properties