搜索结果: 136-150 共查到“理学 stars”相关记录462条 . 查询时间(0.103 秒)
Central Stars of Planetary Nebulae: New spectral classifications and catalogue
Central Stars Planetary Nebulae spectral classifications
2011/1/11
Context. There are more than 3000 true and probable known Galactic Planetary Nebulae (PNe), but only for 13% of them there is central star spectroscopic information available. Aims. To contribute to t...
We present an overview of a few spectroscopic diagnostics of massive stars. We explore the following wavelength ranges: UV (1000 to 2000 A), optical (4000--7000 A) and near-infrared (mainly H and K ba...
There is much debate on how high-mass star formation varies with environment, and whether the sparsest star-forming environments are capable of forming massive stars. To address this issue, we have ob...
Rotation and differential rotation in rapidly rotating field stars
differential rotation rapidly rotating field stars
2011/1/13
We continue our studies on stellar latitudinal differential rotation. The presented work is a sequel of the work of Reiners et al. who studied the spectral line broadening profile of hundreds of stars...
The connection between missing AGB stars and extended horizontal branches
missing AGB stars extended horizontal branches
2011/1/13
Recent surveys confirm early results about a deficiency or even absence of CN-strong stars on the asymptotic giant branch (AGB) of globular clusters (GCs), although with quite large cluster-to-cluster...
The chemical composition of the Orion star-forming region: II. Stars, gas, and dust: the abundance discrepancy conundrum
the Orion star-forming region II. Stars
2011/1/13
We re-examine the recombination/collisional emission line (RL/CEL) nebular abundance discrepancy problem in the light of recent high-quality abundance determinations in young stars in the Orion star-f...
The spin parameter of uniformly rotating compact stars
spin parameter of uniformly compact stars
2010/12/21
We study the dimensionless spin parameter j (= cJ/(GM2)) of uniformly rotating neutron stars
and quark stars in general relativity. We show numerically that the maximum value of the spin
parameter o...
The Mass-Radius(-Rotation?) Relation for Low-Mass Stars
Mass-Radius Relation Low-Mass Stars
2010/11/15
The fundamental properties of low-mass stars are not as well understood as those of their more
massive counterparts. The best method for constraining these properties, especially masses and radii,is ...
The Moving Hotspots model for kHz QPOs in accreting neutron stars
QPO plasma LMXB accretion
2010/11/9
3D MHD simulation of accretion onto neutron stars have shown in the last few years that
the footprint (hotspot) of the accretion flow changes with time. Two different kinds of accretion,namely the fu...
Tkachenko modes in rotating neutron stars: the effect of compressibility and implications for pulsar timing noise
Tkachenko modes rotating neutron stars compressibility pulsar timing noise
2010/11/11
Long wavelength oscillations (Tkachenko waves) of the triangular lattice of quantized vortices in super uid neutron stars have been suggested as one of the possible explanations for the timing noise o...
Tkachenko modes in rotating neutron stars: the effect of compressibility and implications for pulsar timing noise
Tkachenko modes rotating neutron stars effect of compressibility implications pulsar timing noise
2010/12/21
Long wavelength oscillations (Tkachenko waves) of the triangular lattice of quantized vortices in super uid neutron stars have been suggested as one of the possible explanations for the timing noise o...
Revisiting the Flowers-Ruderman instability of magnetic stars
magnetic fields MHD – stars magnetic field
2010/11/10
In 1977, Flowers and Ruderman described a perturbation that destabilises a purely
dipolar magnetic field in a fluid star. They considered the effect of cutting the star
in half along a plane contain...
New Double-Mode and Other RR Lyrae Stars from WASP Data
New Double-Mode Other RR Lyrae Stars from WASP Data
2010/11/11
The data from the first public data release of the exoplanet transit survey WASP (Wide Angle Search for Planets; Butters et al., 2010) were studied for a number of known and suspected RR Lyrae stars (...
Do giant spiral galaxies thwart clusters of young stars?(图)
giant spiral galaxies clusters young stars
2010/11/30
Astronomers in Scotland and Germany say simple physics may explain a long-standing paradox: why large clusters of young stars tend to reside in relatively small galaxies and not in giants like the Mil...
Main-sequence massive stars possess convective cores that likely harbor strong dy-namo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D a...