A5025976595- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- High-pressure geophysics and materials
- Adaptive optics and wavefront sensing
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Aerodynamics and Fluid Dynamics Research
- Laser-induced spectroscopy and plasma
- Material Science and Thermodynamics
- Geophysics and Sensor Technology
- Spacecraft and Cryogenic Technologies
- Inertial Sensor and Navigation
- Photocathodes and Microchannel Plates
- Spectroscopy and Laser Applications
- Synthesis and characterization of novel inorganic/organometallic compounds
- Magnetic properties of thin films
- Advanced Optical Sensing Technologies
University of Amsterdam
2001-2015
Amsterdam University of the Arts
2012
University of Vienna
2009
University of Southern Queensland
2009
Australian Astronomical Observatory
2009
Astronomical Institute of the Slovak Academy of Sciences
1982-2006
Anton Proksch Institut
2002
Georgia State University
1990
Stuttgart Observatory
1990
Vrije Universiteit Amsterdam
1988
Building on results from the Magnetism in Massive Stars (MiMeS) project, this paper shows how a two-parameter classification of massive-star magnetospheres terms magnetic wind confinement (which sets Alfvén radius RA) and stellar rotation Kepler co-rotation RK) provides useful organization both observational signatures theoretical predictions. We compile first comprehensive study inferred observed values for relevant parameters 64 confirmed OB stars with Teff ≳ 16 kK. Using these parameters,...
The dwarf stars in the 26 year period binary alpha Com were predicted to eclipse each other early 2015. That prediction was based on an orbit model made with over 600 astrometric observations using micrometers, speckle interferometry, and long baseline optical interferometry. Unfortunately, it has been realized recently that position angle measurements for three of from ~100 years ago error by 180 degrees, which skewed orbital fit. likely 2 months earlier than predicted, at point system low...
In this paper, we use the very recent spectropolarimetric observations of β Cep collected by Henrichs et al. and propose for star a consistent model large-scale magnetic field associated magnetically confined wind circumstellar environment. A re-examination fundamental parameters in light Hipparcos parallax indicates that is most likely 12-M⊙ with radius 7 R⊙, effective temperature 26 000 K age 12 Myr, viewed an inclination rotation axis about 60°. Using two different modelling strategies,...
An atlas of time series ultraviolet spectra is presented for 10 bright O stars. The were obtained with the International Ultraviolet Explorer during seven observing campaigns lasting several days over a period 6 years. UV P Cygni lines in 9 out studied stars exhibit characteristic pattern variability form discrete absorption components (DACs) migrating through troughs on timescale day to week. This significantly different each star, but remains relatively constant span our observations given...
We present a useful formulation of the surface-velocity field rotating, adiabatically pulsating star, which accounts for effects Coriolis force. use this model to investigate observable spectroscopic characteristics non-radial pulsations. calculate time series absorption line profiles in carefully chosen domain parameter space. Only mono-periodic spheroidal modes are investigated; atmospheric changes due pulsation neglected. The line-profile variations, as well their behavior inferred from...
de niveau recherche, publiés ou non, émanant des établissements d'enseignement et recherche français étrangers, laboratoires publics privés.
We report on attempts to measure the magnetic field of pulsating B star ν Eridani with Musicos spectropolarimeter attached 2 m telescope at Pic du Midi, France. This object is one most extensively studied stars for pulsation modes, and existence a was suggested from inequality frequency separations triplet in stars' oscillation spectrum. show that inferred 5-10 kG not present during our observations, which cover about year. discuss influence strong pulsations analysis strength set an upper...
The colliding-wind binary system WR 140 (HD 193793, WC7pd+O4-5, P = 7.94 yr) was monitored in the ultraviolet by IUE from 1979 to 1994 35 short-wavelength high-resolution spectra. An absorption-line radial-velocity solution is obtained photospheric lines of O component, comparison with a single star. resulting orbital parameters, e 0.87 ± 0.05, ω 31° 9° and 25 15 km s-1, confirm large eccentricity orbit, within uncertainties previous optical studies. This brings weighted mean UV-optical 0.85...
We present results from the 1996 Multi-Site Continuous Spectroscopy (MUSICOS) campaign on T Tauri star SU Aurigae. find a 2.7-d periodicity in He i (587.6 nm) line, and somewhat longer, less well-pronounced periodicities Balmer lines Na D. Our observations support suggestion that wind infall signatures are out of phase Aur. Doppler images Aur have been obtained least-squares deconvolved profiles. Images taken about one rotation apart show only limited overlap, particular at low latitudes....
Presentation du congres qui s'est tenu a l'Universite de Colorado 17 au 19 avril 1985. Le lien entre les pulsations non radiales et la perte masse dans certaines etoiles O B(e) profondement change perception des vents stellaires premier type
view Abstract Citations (24) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Recurrent Episodic Mass Loss in a B2e Star: 66 Ophiuchi, 1982--1985 Grady, C. A. ; Sonneborn, George Wu, Chi-Chao Henrichs, H. F. The results of three intensive ultraviolet monitoring campaigns for Oph September-October 1982, September 1983, and 1984, supplemented by the available IUE archival data from April, 1982 to June, 1985 are reported. stellar wind went through...
view Abstract Citations (17) References (34) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Complex Wind of the Central Star Planetary Nebula Abell 78 Kaler, James B. ; Feibelman, Walter A. Henrichs, H. F. authors have observed with high-dispersion camera IUE broad P Cygni profiles C IV, N V, and O V that arise from 78's nucleus. They find a terminal velocity to wind is close 3670±30 km s-1, positive gradient, an approximate mass loss rate...
A simplified version of the random blob ejection model Underhill & Fahey is presented, in which we consider ejected material to be a localized mass enhancement flowing with stellar wind. Model results are presented for one particular choice radial velocity law