Search Publications
High latitude ULYSSES observations of CIR accelerated ions and electrons
Simnett, G. M.; Sayle, K. A.
From the comparison of the intensity maxima of ~ 1 MeV/nuc. ions with those of the 40-65 keV electrons and higher energy ions ( ~ 2-4 and 4-8 MeV/nuc.), during Ulysses' ascent to the solar south pole, 1992-1994, evidence has been found for the ~ 1 MeV/nuc. ions observed at high latitude by the Ulysses spacecraft to have originated at mid-latitudes…
Magnetic field models for A and B stars. V. The magnetic field and photometric variation of 84 Ursae Majoris
Manset, N.; Wade, G. A.; Bastien, P. +2 more
We present new longitudinal magnetic field and Stroemgren photometric measurements of the Bp star 84 UMa. From these data we determine a new rotational period Prot=1.38576 deg +/- 0.00080 deg, which is inconsistent with previously published values. The magnetic measurements indicate the presence of a weak, dominantly dipolar magnetic fi…
D/H-ratio: Observations with ORFEUS II
Werner, K.; Grewing, M.; Appenzeller, I. +12 more
During the second flight of the ORFEUS-SPAS satellite (Nov./Dec. 96) high resolution (λ/{Deltalambda} = 10,000) Echelle-spectra of BD +28^\circ 4211 in the wavelength regime 912 - 1400 Angstroms have been taken. Deuterium can be clearly identified in the ORFEUS-II Echelle-spectra of this star. For the first time it was possible to take spectra of …
Recalibration of the Wilson-Bappu Effect Using the Singly Ionized Magnesium K Line
Mena-Werth, Jose; Scoville, Frederick
A new calibration of the Wilson-Bappu effect is presented using data from a survey of the singly ionized magnesium (Mg ii) h and k lines (near 280 nm) taken from the archives of the International Ultraviolet Explorer satellite. Our sample consisted of 94 stars with absolute magnitudes derived from parallaxes reported from Hipparcos. We describe th…
The space distribution of HIPPARCOS carbon stars
Bergeat, J.; Knapik, A.; Rutily, B.
More than 300 galactic carbon-rich stars have been observed by the HIPPARCOS satellite. Parallaxes and proper motions are given with an unprecedented accuracy. Carbon stars are however distant giants and there are only 4 stars with a parallax accuracy better than 20 % (26 stars if 30 %). Direct use of observed data is thus severely hampered by sta…
Spectroscopic binary orbits from ultraviolet radial velocities. Paper 27: Tau Canis Majoris (HD 57061)
Stickland, D. J.; Lloyd, C.; Sweet, I.
Observational Evidence for the Effect of Amplification Bias in Gravitational Microlensing Experiments
Han, Cheongho; Kim, Ho-Il; Jeong, Youngjin
Recently Alard, Mao, & Guibert and Alard proposed to detect the shift of a star's image centroid, δx, as a method to identify the lensed source among blended stars. Goldberg & Woźniak actually applied this method to the OGLE-1 database and found that seven of 15 events showed significant centroid shifts of δx >~ 0.2". The amount of cent…
Absolute magnitudes and kinematics of CP stars from HIPPARCOS data
Luri, X.; Figueras, F.; Torra, J. +5 more
The position in the HR diagram and the kinematic characteristics of different kinds of CP stars of the upper main sequence are obtained using the LM method of Luri et al. Most of the CP stars are main sequence stars occupying the whole width of the sequence. From a kinematic point of view, they belong to the young disk population (ages < 1.5 Gy…
Jovian radio “bullseyes” observed by Ulysses
MacDowall, R. J.; Kaiser, M. L.
We report the observation of extremely rare semi-bullseye or target-like features in the dynamic spectra of Jupiter obtained in 1991-1994 by the Ulysses Unified Radio and Plasma wave instrument. The emissions lie in the 20-50 kHz band and consist of narrow band (∼1-2 kHz) semi-concentric wisps on frequency-time dynamic spectra. The individual wisp…
ISO observations of the radio-loud BALQSO 1556+3517
Clavel, J.
To date, the quasar 1556+3517 is the only radio loud Broad Absorption Line QSO (BALQSO; Becker et al. 1997). This prompted narrow band filter imaging observations in the range 4-15 mu with the ISO satellite. The source is clearly detected in all filters and appears point-like and isolated at the resolution of ISO. The overall Spectral Energy Distr…