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Related papers: Characterization of the Red Giant HR 2582 Using th…

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The bright star 55 Cancri is known to host five planets, including a transiting super-Earth. We use the CHARA Array to directly determine the following of 55 Cnc's stellar astrophysical parameters: $R=0.943 \pm 0.010 R_{\odot}$, $T_{\rm…

When low- and intermediate-mass stars evolve off the main sequence, they expand and cool into the red giant stages of evolution, which include those associated with shell H burning (the red giant branch), core He burning (the red clump),…

We present observations of a very massive galaxy at z=1.82 which show that its morphology, size, velocity dispersion and stellar population properties that are fully consistent with those expected for passively evolving progenitors of…

\alpha^1 Her is the second closest Asymptotic Giant Branch (AGB) star to the Sun, and the variable luminous M5 Ib-II member of a triple stellar system containing G8 III and A9 IV-V components. However, the mass of this important star was…

Solar and Stellar Astrophysics · Physics 2013-11-11 Ehsan Moravveji , Edward F. Guinan , Habib G. Khosroshahi , Rick Wasatonic

We analyze a 96 ks Chandra/HETGS observation of the single G-type giant HR 9024. The high flux allows us to examine spectral line and continuum diagnostics at high temporal resolution, to derive plasma parameters. A time-dependent 1D…

Astrophysics · Physics 2011-02-11 Paola Testa , Fabio Reale , David Garcia-Alvarez , David P. Huenemoerder

HD 142527 is a young pre-main sequence star with properties indicative of the presence of a giant planet or/and a low-mass stellar companion. We have analyzed an X-Shooter/Very Large Telescope spectrum to provide accurate stellar parameters…

Solar and Stellar Astrophysics · Physics 2014-07-08 I. Mendigutía , J. Fairlamb , B. Montesinos , R. D. Oudmaijer , J. R. Najita , S. D. Brittain , M. E. van den Ancker

We show that the masses of red giant stars can be well predicted from their photospheric carbon and nitrogen abundances, in conjunction with their spectroscopic stellar labels log g, Teff, and [Fe/H]. This is qualitatively expected from…

There is plenty of evidence in the literature of significant discrepancies between the observations and models of metal-poor red giant branch stars, in particular regarding the effective temperature, teff, scale. We revisit the benchmark…

Solar and Stellar Astrophysics · Physics 2024-09-18 O. L. Creevey , S. Cassisi , F. Thévenin , M. Salaris , A. Pietrinferni

We initiated long-term optical interferometry monitoring of the diameters of unstable yellow hypergiants (YHG) with the goal of detecting both the long-term evolution of their radius and shorter term formation related to large mass-loss…

Debate over the planet occurrence rates around intermediate-mass stars has hinged on the accurate determination of masses of evolved stars, and has been exacerbated by a paucity of reliable, directly-measured fundamental properties for…

We present observations of the A7IV-V star Alderamin ($\alpha$ Cep, HR 8162, HD 203280) from the Georgia State University CHARA Array. These infrared interferometric angular size measurements indicate a non-circular projected disk…

Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (<25Mo). For many years their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar atmosphere models, we have…

We present a V-I color-magnitude diagram for a region 1'-2' from the center of M32 based on Hubble Space Telescope WFPC2 images. The broad color-luminosity distribution of red giants shows that the stellar population comprises stars with a…

We present an in-depth analysis of the bright subgiant HR 7322 (KIC 10005473) using Kepler short-cadence photometry, optical interferometry from CHARA, high-resolution spectra from SONG, and stellar modelling using GARSTEC grids and the…

The cool hypergiant star RW Cephei is currently in a deep photometric minimum that began several years ago. This event bears a strong similarity to the Great Dimming of the red supergiant Betelgeuse that occurred in 2019-2020. We present…

Context: The main sequence binary star 61 Cyg (K5V+K7V) is our nearest stellar neighbour in the northern hemisphere. This proximity makes it a particularly well suited system for very high accuracy interferometric radius measurements. Aims:…

We investigate the properties of 1262 red giant stars with high photospheric abundances of lithium observed by the GALAH and \Ktwo-HERMES surveys, and discuss them in the context of proposed mechanisms for lithium enrichment and…

The thin red giant branch (RGB) of the Carina dwarf spheroidal galaxy appears at first sight quite puzzling and seemingly in contrast with the presence of several distinct bursts of star formation. In this Letter, we provide a measurement…

Astrophysics · Physics 2009-11-07 L. Rizzi , E. V. Held , G. Bertelli , I. Saviane

New evidence provided by the Gaia satellite places the location of the runaway star J01020100-7122208 in the halo of the Milky Way (MW) rather than in the Small Magellanic Cloud as previously thought. We conduct a reanalysis of the star's…

Solar and Stellar Astrophysics · Physics 2018-11-28 Philip Massey , Stephen E. Levine , Kathryn F. Neugent , Emily Levesque , Nidia Morrell , Brian Skiff

Physical processes working in the stellar interiors as well as the evolution of stars depend on some fundamental stellar properties, such as mass, radius, luminosity, and chemical abundances. A classical way to test stellar interior models…