Search Publications
Fourier Analysis of Hipparcos Photometry of Cepheid Variables
Moskalik, P.; Ogloza, W.; Zakrzewski, B.
Fourier parameters have been computed for 240 field Cepheids observed by the Hipparcos satellite. We have identified three new PopulationI overtone Cepheids: V411Lac, V898 Cen and V572 Aql. We have compared Fourier progressions of Population I and Population II Cepheids. The possibility of using Fourier parameters to distinguish between the two ty…
The nearby M-dwarf system Gliese 866 revisited
Franz, O. G.; Leinert, Ch.; Jahreiß, H. +3 more
We present an improved orbit determination for the visual pair in the M-dwarf triple system
IRAS 03201+5459: a C-rich AGB star with silicate absorption
Szczerba, R.; Jiang, B. W.; Deguchi, S.
IRAS 03201+5459 is a late-type star with a circumstellar envelope according to its IRAS color. It has no identification at optical or near-infrared wavelengths. A full ISO-SWS spectrum between 2.3 and 43 mu m was taken at a resolution of about ~ 300 to investigate its nature. The spectrum shows the 9.7 mu m feature in absorption, usually seen in O…
Observation of Shock Waves Associated with Coronal Mass Ejections from SOHO/LASCO
Kosovichev, A. G.; Stepanova, T. V.
Theoretical models of coronal mass ejections (CME) predict formation of shock waves in front of eruptive magnetic structures, loops and arches. These shock waves have been detected in the solar wind at large distances from the Sun. However, their observation at short distances in the solar corona has been difficult. We have attempted to identify t…
V751 Cyg and V Sge as transient supersoft X-ray sources
Greiner, Jochen
I review the observational evidence for luminous, soft X-ray emission during optical low-states in the two cataclysmic variables V751 Cyg and V Sge, and discuss the possible link to the canonical supersoft X-ray sources.
A catalogue of galaxies in the HDF-South: Photometry and structural parameters
Chincarini, G.; Saracco, P.; Volonteri, M.
We describe the construction of a catalogue of galaxies in the optical field of the Hubble Deep Field South. The HDF-S observations produced WFPC2 images in U, B, V, and I, the version 1 data have been made public on 23 November 1999. The effective field of view is 4.38 arcmin2, and the 5sigma limiting magnitudes (in a FWHM aperture) ar…
No QPO time lags from Sco X-1 as seen with EXOSAT: a comparison with Cyg X-2
Kuulkers, Erik; van der Klis, Michiel; Lamb, Frederick K. +2 more
We have measured the phase-delay and rms amplitude spectra of Cyg X-2 and Sco X-1. Using EXOSAT data from the normal branch of Cyg X-2 we confirm earlier (Ginga) results, showing that at an energy near 6 keV there is both a minimum in the quasi-periodic oscillations QPO rms amplitude spectrum and a 150deg phase jump in the QPO phase-del…
Star Formation and Tidal Encounters with the Low Surface Brightness Galaxy UGC 12695 and Companions
McGaugh, S. S.; O'Neil, K.; Verheijen, M. A. W.
We present VLA H I observations of the low surface brightness (LSB) galaxy UGC 12695 and its two companions, UGC 12687 and a newly discovered dwarf galaxy 2333+1234. UGC 12695 shows solid-body rotation but has a very lopsided morphology of the H I disk, with the majority of the H I lying in the southern arm of the galaxy. The H I column density di…
A Color Analysis of the NICMOS Parallel Image Archive
Schneider, Glenn; Rieke, Marcia J.; Thompson, Rodger I. +2 more
We present a photometric analysis of all high Galactic latitude (|b|>20deg) broadband parallel images taken by the Near-Infrared Camera and Multi-Object Spectrometer instrument of the Hubble Space Telescope during its initial lifetime in HST Cycle 7. These images, taken through the F110W and F160W filters, reach a mean 3 σ limiting m…
Comet Shoemaker-Levy 9 Dust Size and Velocity Distributions
Hahn, Joseph M.; Rettig, Terrence W.
Pre-impact observations of Comet Shoemaker-Levy 9 (S-L9) obtained with the Hubble Space Telescope are examined, and a model of an active, dust-producing comet is fitted to images of fragments G, H, K, and L. The model assumes steady isotropic dust emission from each fragment's sunlit hemisphere. Best-fit results indicate that the dominant light-sc…