搜索结果: 1-15 共查到“天文学 poor”相关记录21条 . 查询时间(0.015 秒)
Vibrational Instability of Metal-Poor Low-Mass Main-Sequence Stars
Vibrational Instability Metal-Poor Low-Mass Main-Sequence Stars
2012/2/24
We find that low-degree low-order g-modes become unstable in metal-poor low-mass stars due to the $\varepsilon$-mechanism of the pp-chain. Since the outer convection zone of these stars is limited onl...
GRB 070125 and the environments of spectral-line poor afterglow absorbers
gamma-ray burst: individual: GRB070125
2011/10/11
GRB 070125 is among the most energetic bursts detected and the most extensively observed so far. Nevertheless, unresolved issues are still open in the literature on the physics of the afterglow and on...
An aluminum/calcium-rich, iron-poor, white dwarf star: evidence for an extrasolar planetary lithosphere?
calcium-rich iron-poor evidence extrasolar planetary lithosphere
2011/10/8
The presence of elements heavier than helium in white dwarf atmospheres is often a signpost for the existence of rocky objects that currently or previously orbited these stars. We have measured the ab...
Center-to-Limb Variation of Radio Emissions from Thermal-Rich and Thermal-Poor Solar Flares
acceleration of particles—Sun: fl ares—Sun: magnetic fi elds—Sun:radio radiation—Sun: X-rays, gamma rays
2011/9/30
A statistical analysis of radio flare events was performed by using the event list of Nobeyama Radioheliograph in 1996-2009. We examined center-to-limb variations of 17GHz and 34GHz flux by dividing t...
The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy
The Stellar Abundances for Galactic Archaeology Database II
2011/1/13
We discuss the characteristics of known extremely metal-poor (EMP) stars in the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA) database (Suda et al. 2008, PASJ, 60, 1159).The anal...
Hot-Dust-Poor Quasars in Mid-Infrared and Optically Selected Samples
galaxies evolution quasars general surveys
2010/11/9
We show that the Hot-Dust-Poor (HDP) quasars found in the X-ray selected XMM-COSMOS type
1 AGN sample are just as common in two samples selected at optical/infrared wavelengthes: the
Richards et al....
The HARPS search for southern extrasolar planets XXV. Results from the metal-poor sample
planets and satellites formation – Stars abundances – planetary systems – Techniques spectroscopic – Techniques
2010/11/12
Searching for extrasolar planets around stars of different metallicity may provide strong constraints to the models of planet formation and evolution. In this paper we present the overall results of a...
A Carbon-enhanced Metal-poor Damped Lyman alpha System: Probing Gas from Population III Nucleosynthesis?
galaxies abundances − galaxies evolution − quasars absorption lines quasars: individual J0035− 0918 − stars carbon − stars
2010/11/10
We present high resolution observations of an extremely metal-poor damped Ly system, at zabs = 2.3400972 in the spectrum of the QSO J0035−0918, exhibiting an abundance pattern consistent with mo...
Very metal-poor stars are of obvious importance for many problems in chemical evolution, star formation, and galaxy evolution. Finding complete samples of such stars which are also bright enough to al...
Asteroseismic modelling of the metal-poor star Tau Ceti
Solar and Stellar Astrophysics (astro-ph.SR)
2011/1/5
Asteroseismology is an effcient tool not only for testing stellar structure and evolutionary theory but also constraining the parameters of stars for which solar-like oscillations are detected, presen...
Lyman `bump' galaxies - II. A possible signature of massive extremely metal-poor or metal-free stars in z=3.1 Ly-alpha emitters
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/29
Deep NB359 imaging with Subaru by Iwata et al. have detected surprisingly strong Lyman continuum (LyC; ~900A in the rest-frame) from some LAEs at z=3.1. However, the redshifts might be misidentified d...
Chemical abundances in metal-poor giants: limitations imposed by the use of classical 1D stellar atmosphere models
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/29
In this work we have used 3D hydrodynamical (CO5BOLD) and 1D hydrostatic (LHD) stellar atmosphere models to study the importance of convection and horizontal temperature inhomogeneities in stellar abu...
Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars II. s-process nucleosynthesis during the core He flash
Solar and Stellar Astrophysics (astro-ph.SR)
2010/12/28
Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant bra...
WASP-32b: A transiting hot Jupiter planet orbiting a lithium-poor, solar-type star
Earth and Planetary Astrophysics (astro-ph.EP)
2010/12/28
We report the discovery of a transiting planet orbiting the star TYC 2-1155-1. The star, WASP-32, is a moderately bright (V=11.3) solar-type star (Teff=6100 +- 100K, [Fe/H] = -0.13 +- 0.10).
A deep Chandra observation of the poor cluster AWM4 - II. The role of the radio jets in enriching the intra-cluster medium
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/23
We use a Chandra observation of the poor cluster AWM4 to map the temperature and abundance of the intra-cluster medium, so as to examine the influence of the central radio galaxy on its environment.