Results 41 to 50 of about 13,326 (291)
Why hot horizontal branch stars can appear redder than red giants [PDF]
Astronomy & Astrophysics, 2003 In this paper we report on a curious feature in the V, (U-B) color-magnitude diagrams of globular clusters. In our database, we find that a considerable fraction of blue horizontal branch stars, hotter than the instability strip and cooler than the Grundahl et al.
AL MOMANY, YAZAN +6 more
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, 2003 We present a comparison between theoretical models and the observed magnitude difference between the horizontal branch and the red giant branch bump for a sample of 53 clusters. We find a general agreement, though some discrepancy is still present at the two extremes of the metallicity range of globular clusters.
RIELLO M. +4 more
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Monte Carlo Simulations of Globular Cluster Red Giant Branches [PDF]
Symposium - International Astronomical Union, 1984 Simulations of globular cluster luminosity functions have shown that many of the features observed in actual clusters are probably statistical fluctuations. We suggest one new way of looking at the data which may ultimately lead to some information about the physical parameters of clusters.
Deborah A. Crocker, Robert T. Rood
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Exploring the Upper Red Giant and Asymptotic Giant Branches: The Globular Cluster M5 [PDF]
The Astrophysical Journal, 2004 We have tabulated lists of upper red giant, horizontal, and asymptotic giant branch (RGB, HB, AGB) stars in the globular cluster M5 that are complete to over 10' from the core for the RGB and AGB samples, and 8' for the HB sample. The large samples give us the most precise value of R_2 = N_AGB / N_HB to date for a single globular cluster (0.176 +/- 0 ...
Sandquist, Eric L., Bolte, Michael
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Radial pulsations of red giant branch stars [PDF]
Astronomy Letters, 2017 We performed hydrodynamic computations of nonlinear stellar pulsations of population I stars at the evolutionary stages of the ascending red giant branch and the following luminosity drop due to the core helium flash. Red giants populating this region of the Hertzsprung--Russel diagram were found to be the fundamental mode pulsators.
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Red-giant branch stellar cores as macroscopic dark matter detectors
Physical Review D, 2022 We show that macroscopic dark matter (DM) impacts on the degenerate helium cores of red-giant branch (RGB) stars can ignite helium fusion via DM-baryon elastic scattering. The onset of helium burning leads to a characteristic drop in luminosity and rise in temperature that marks the transition to a horizontal branch star.
Christopher Dessert, Zachary Johnson
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The spectroscopic indistinguishability of red giant branch and red clump stars [PDF]
Astronomy & Astrophysics, 2016 Stellar spectroscopy provides useful information on the physical properties of stars such as effective temperature, metallicity and surface gravity (log g). However, those photospheric characteristics are often hampered by systematic uncertainties. The joint spectro-seismo project (APOKASC) of field red giants has revealed a puzzling offset between the
T. Masseron, K. Hawkins
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Advanced Healthcare Materials, EarlyView.Membrane fusion‐inspired nanomaterials offer transformative potential in diagnostics by mimicking natural fusion processes to achieve highly sensitive and specific detection of disease biomarkers. This review highlights recent advancements in nanomaterial functionalization strategies, signal amplification systems, and stimuli‐responsive fusion designs,
Sojeong Lee +9 more
wiley +1 more source
CHEMICAL INHOMOGENEITY IN RED GIANT BRANCH STARS AND RR LYRAE VARIABLES IN NGC 1851: TWO SUBPOPULATIONS IN RED GIANT BRANCH [PDF]
The Astrophysical Journal, 2009 We investigate the red giant branch (RGB) subpopulations of NGC 1851 using Ca uvby photometry. Our color-magnitude diagrams show that the RGB stars have two subpopulations and the RGB stars in NGC 1851 appear to have distinct elemental abundance patterns with the [Ca/H] abundance. We discuss that the elemental abundance patterns can be explained by the
Lee, Jae-Woo +7 more
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Advanced Materials, EarlyView.Transition metal oxy/carbo‐nitrides show great promise as catalysts for sustainable processes. A Mn‐Mo mixed‐metal oxynitride attains remarkable performance for the direct synthesis of acetonitrile, an important commodity chemical, via sequential C─N and C─C coupling from syngas (C1) and ammonia (N1) feedstocks.
M. Elena Martínez‐Monje +7 more
wiley +1 more source