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Related papers: The PTI Carbon Star Angular Size Survey: Effective…

200 papers

We study the spectroscopic and photometric properties of carbon stars. In the first paper of this series we focus on objects that can be described by hydrostatic models neglecting dynamical phenomena like pulsation and mass loss. As a…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. Aringer , L. Girardi , W. Nowotny , P. Marigo , M. T. Lederer

Our comprehension of stellar evolution on the AGB still faces many difficulties. To improve on this, a quantified understanding of large-amplitude pulsator atmospheres and interpretation in terms of their fundamental stellar parameters are…

Solar and Stellar Astrophysics · Physics 2015-06-03 M. Hillen , T. Verhoelst , P. Degroote , B. Acke , H. van Winckel

Representative samples of F-, G-, K-type stars located out of the Solar Neighbourhood has started to be available in spectroscopic surveys. The fraction of metal-poor ([Fe/H]~$\lesssim -0.8$~dex) giants becomes increasingly relevant to far…

Stellar spectra with a high resolution of 115000 obtained with the HARPS spectrograph provide an opportunity to examine turbulence velocities and their depth distributions in the photosphere of stars. Fourier analysis was performed for 17…

Solar and Stellar Astrophysics · Physics 2019-07-30 Sheminova V. A

A non-LTE analysis of C I lines at 1.068-1.069 micron was carried out for selected 46 halo/disk stars covering a wide metallicity range (-3.7 <[Fe/H]< +0.3), based on the spectral data collected with IRCS+AO188 of the Subaru Telescope, in…

Solar and Stellar Astrophysics · Physics 2015-06-15 Yoichi Takeda , Masahide Takada-Hidai

We present model atmospheres for an Earth-like planet orbiting the entire grid of main sequence FGK stars with effective temperatures ranging from Teff = 4250K to Teff = 7000K in 250K intervals. We model the remotely detectable spectra of…

Earth and Planetary Astrophysics · Physics 2013-04-11 Sarah Rugheimer , Lisa Kaltenegger , Andras Zsom , Antígona Segura , Dimitar Sasselov

One of the main goals of the COROT mission is to get precise photometric observations of selected bright stars in order to allow the modelling of their interior through asteroseismology. However, in order to interpret the…

Astrophysics · Physics 2009-11-11 M. Gillon , P. Magain

Measurements of masses and ages of young stars from their location in the HR diagram are limited by not only the typical observational uncertainties that apply to field stars, but also by large systematic uncertainties related to…

Solar and Stellar Astrophysics · Physics 2015-06-19 Gregory J. Herczeg , Lynne A. Hillenbrand

In the light of the recent results of the stellar interferometry, we examine the nature of the extra molecular layer outside the photosphere of red super- giant stars, so far studied mostly with the use of the infrared spectra. Although the…

Astrophysics · Physics 2009-11-11 Takashi Tsuji

We consider fifty transiting short-period giant planets for which eclipse depths have been measured at multiple infrared wavelengths. The aggregate dayside emission spectrum of these planets exhibits no molecular features, nor is brightness…

Earth and Planetary Astrophysics · Physics 2015-06-24 Joel C. Schwartz , Nicolas B. Cowan

A new dataset of atomic oxygen and molecular nitrogen number density profiles, along with thermospheric temperature profiles between 180 and 500 km, has been developed. These profiles are derived from solar occultation measurements made by…

The temperature is a central parameter affecting the chemical and physical properties of dense cores of interstellar clouds and their evolution to star formation. The chemistry and the dust properties are temperature dependent and the…

Astrophysics of Galaxies · Physics 2015-06-03 M. Juvela , J. Harju , N. Ysard , T. Lunttila

Infrared spectroscopic observations have established the presence of hydrocarbon ices on Pluto and other TNOs, but the abundances of such molecules cannot be deduced without accurate optical constants (n, k) and reference spectra. In this…

Instrumentation and Methods for Astrophysics · Physics 2015-02-10 R. L. Hudson , P. A. Gerakines , M. H. Moore

Observations of 48 red-clump stars were obtained in the H band with the PIONIER instrument installed at the Very Large Telescope Interferometer. Limb-darkened angular diameters were measured by fitting radial intensity profile I(r) to…

Solar and Stellar Astrophysics · Physics 2018-08-22 A. Gallenne , G. Pietrzyński , D. Graczyk , N. Nardetto , A. Mérand , P. Kervella , W. Gieren , S. Villanova , R. E. Mennickent , B. Pilecki

The detailed chemical composition of stars is important in many astrophysical fields, among which the characterisation of exoplanetary systems. Previous studies seem to indicate an anomalous chemical pattern of the youngest stellar…

The ratio of the depths of spectral lines is a powerful indicator of the effective temperature. The method based on this analysis is capable of discerning small temperature variations of individual stars. We apply this spectroscopic data…

Astrophysics · Physics 2007-05-23 K. Biazzo , A. Frasca , S. Catalano , E. Marilli

We have mapped the C I 3P1-3P0 line at 492 GHzin three molecular clouds immersed in weak ultraviolet radiation fields, TMC-1, L134N, and IC 5146. In all three clouds, the CI peak TA* ~ 1 K, with very small dispersion. The spatial C I…

Astrophysics · Physics 2009-10-31 K. Tatematsu , D. T. Jaffe , R. Plume , N. J. Evans , J. Keene

We derive an empirical effective temperature and bolometric luminosity calibration for G and K dwarfs, by applying our own implementation of the InfraRed Flux Method to multi-band photometry. Our study is based on 104 stars for which we…

Astrophysics · Physics 2009-11-11 L. Casagrande , L. Portinari , C. Flynn

New space missions (e.g., NASA-TESS and ESA-PLATO) will perform an analysis of bright stars in large fields of the celestial sphere searching for extraterrestrial planets. Asteroseismic observations will search for exoplanet-hosting stars…

The distribution of stellar $\mathrm{H}\alpha$ chromospheric activity with respect to stellar atmospheric parameters (effective temperature $T_\mathrm{eff}$, surface gravity $\log\,g$, and metallicity $\mathrm{[Fe/H]}$) and…

Solar and Stellar Astrophysics · Physics 2023-08-01 Han He , Weitao Zhang , Haotong Zhang , Song Wang , Ali Luo , Jun Zhang