Showing 2007 · astro-phShow all

65 papers · 2 filters

astro-ph2007★ 178 cited

Accretion funnels onto weakly magnetized young stars

N. Bessolaz, C. Zanni, J. Ferreira +2

Aims : We re-examine the conditions required to steadily deviate an accretion flow from a circumstellar disc into a magnetospheric funnel flow onto a slow rotating young forming st…

astro-ph2007★ 53 cited

The pulsation modes of the pre-white dwarf PG 1159-035

J. E. S. Costa, S. O. Kepler, D. E. Winget +74

PG 1159-035, a pre-white dwarf with T_eff=140,000 K, is the prototype of both two classes: the PG1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-0…

astro-ph2007

An infrared view of (candidate accretion) disks around massive young stars

A. Bik, A. Lenorzer, W-. F. Thi +4

Near-infrared surveys of high-mass star-forming regions start to shed light onto their stellar content. A particular class of objects found in these regions, the so-called massive…

astro-ph2007★ 1 cited

Magnetic fields in massive stars

S. Hubrig, M. Schoeller, M. Briquet +9

We review the recent discoveries of magnetic fields in different types of massive stars and briefly discuss strategies for spectropolarimetric observations to be carried out in the…

astro-ph2007★ 10 cited

Resolving the ionized wind of the post-Red Supergiant IRC +10 420 with VLTI/AMBER

W. J. de Wit, R. D. Oudmaijer, M. A. T. Groenewegen +3

The paper investigates the milli-arcsecond scale structure of the present-day mass-loss of the post-Red Supergiant IRC+10420. We use three telescopes of the VLT Interferometer in c…

astro-ph2007★ 1 cited

Folding ion rays in comet C/2004 Q2 (Machholz) and the connection with the solar wind

P. Degroote, D. Bodewits, M. Reyniers

The appearance of folding ion rays in cometary comae is still not very well understood, so our aim is to gain more insight into the role of the local solar wind in the formation of…

astro-ph2007★ 92 cited

A spectroscopic study of southern (candidate) gamma Doradus stars. II. Detailed abundance analysis and fundamental parameters

H. Bruntt, P. De Cat, C. Aerts

The gamma Doradus stars are a recent class of variable main sequence F-type stars located on the red edge of the Cepheid instability strip. They pulsate in gravity modes, and this…

astro-ph2007★ 3 cited

Oscillations in Procyon A: First results from a multi-site campaign

S. Hekker, T. Arentoft, H. Kjeldsen +45

Procyon A is a bright F5IV star in a binary system. Although the distance, mass and angular diameter of this star are all known with high precision, the exact evolutionary state is…

astro-ph2007★ 198 cited

Automated supervised classification of variable stars I. Methodology

J. Debosscher, L. M. Sarro, C. Aerts +4

The fast classification of new variable stars is an important step in making them available for further research. Selection of science targets from large databases is much more eff…

astro-ph2007★ 127 cited

Three Dimensional MHD Wave Propagation and Conversion to Alfven Waves near the Solar Surface. I. Direct Numerical Solution

P. S. Cally, M. Goossens

The efficacy of fast/slow MHD mode conversion in the surface layers of sunspots has been demonstrated over recent years using a number of modelling techniques, including ray theory…

astro-ph2007★ 1.5k cited

Evolution of asymptotic giant branch stars II. Optical to far-infrared isochrones with improved TP-AGB models

Paola Marigo, Leo Girardi, Alessandro Bressan +3

We present a large set of theoretical isochrones, whose distinctive features mostly reside on the greatly improved treatment of the thermally pulsing asymptotic giant branch (TP-AG…

astro-ph2007★ 3 cited

Radial velocities of giant stars: an investigation of line profile variations

S. Hekker, I. A. G. Snellen, C. Aerts +3

Since 1999, a radial velocity survey of 179 red giant stars is ongoing at Lick Observatory with a one month cadence. At present ~20-100 measurements have been collected per star wi…

astro-ph2007★ 7 cited

Blob formation and acceleration in the solar wind: role of converging flows and viscosity

Giovanni Lapenta, Anna Lisa Restante

The effect of viscosity and of converging flows on the formation of blobs in the slow solar wind is analysed by means of resistive MHD simulations. The regions above coronal stream…

astro-ph2007

The formation and evolution of very massive stars in dense stellar systems

H. Belkus, J. Van Bever, D. Vanbeveren

The early evolution of dense stellar systems is governed by massive single star and binary evolution. Core collapse of dense massive star clusters can lead to the formation of very…

astro-ph2007★ 6 cited

Close-up of primary and secondary asteroseismic CoRoT targets and the ground-based follow-up observations

K. Uytterhoeven, E. Poretti, M. Rainer +13

To optimise the science results of the asteroseismic part of the CoRoT satellite mission a complementary simultaneous ground-based observational campaign is organised for selected…

astro-ph2007★ 17 cited

The Magellanic Clouds as a template for the study of stellar populations and galaxy interactions

M. -R. L. Cioni, K. Bekki, G. Clementini +18

The Magellanic System represents one of the best places to study the formation and evolution of galaxies. Photometric surveys of various depths, areas and wavelengths have had a si…

astro-ph2007★ 58 cited

A Search for Mid-Infrared Molecular Hydrogen Emission from Protoplanetary Disks

A. Carmona, M. E van den Ancker, Th. Henning +6

We observed the Herbig Ae/Be stars UX Ori, HD 34282, HD 100453, HD 101412, HD 104237 and HD 142666, and the T Tauri star HD 319139 and searched for H2 0-0 S(2) emission at 12.278 m…

astro-ph2007★ 41 cited

Transverse stability of relativistic two-component jets

Z. Meliani, R. Keppens

Context: Astrophysical jets from various sources seem to be stratified, with a fast inner jet and a slower outer jet. As it is likely that the launching mechanism for each componen…

astro-ph2007★ 55 cited

Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy

M. Matsuura, A. A. Zijlstra, J. Bernard-Salas +10

We have observed five carbon-rich AGB stars in the Fornax dwarf spheroidal (dSph) galaxy, using the Infrared Spectrometer on board the Spitzer Space Telescope. The stars were selec…

astro-ph2007★ 43 cited

Dust-grain processing in circumbinary discs around evolved binaries. The RV Tauri spectral twins RU Cen and AC Her

C. Gielen, H. Van Winckel, L. B. F. M. Waters +2

Context: We study the structure and evolution of circumstellar discs around evolved binaries and their impact on the evolution of the central system. Aims: To study in detail the b…

astro-ph2007★ 5 cited

Correlated flares in models of a magnetized "canopy"

M. Baiesi, C. Maes, B. M. Shergelashvili

A model of the Lu-Hamilton kind is applied to the study of critical behavior of the magnetized solar atmosphere. The main novelty is that its driving is done via sources undergoing…

astro-ph2007★ 13 cited

Amplification of compressional MHD waves in systems with forced entropy oscillations

B. M. Shergelashvili, C. Maes, S. Poedts +1

The propagation of compressional MHD waves is studied for an externally driven system. It is assumed that the combined action of the external sources and sinks of the entropy resul…

astro-ph2007★ 54 cited

The molecular and dusty composition of Betelgeuse's inner circumstellar environment

Guy Perrin, Tijl Verhoelst, Stephen T. Ridgway +6

The study of the atmosphere of red supergiant stars in general and of Betelgeuse (alpha Orionis) in particular is of prime importance to understand dust formation and how mass is l…

astro-ph2007★ 146 cited

Asteroseismology and Interferometry

M. S. Cunha, C. Aerts, J. Christensen-Dalsgaard +22

Asteroseismology provides us with a unique opportunity to improve our understanding of stellar structure and evolution. Recent developments, including the first systematic studies…