Search Publications
Low Mass Stars in an Outer Field in NGC 6397
Casertano, Stefano; Ballester, Gilda E.; Crisp, David +13 more
We have imagined a field 10' from the center of the globular cluster NGC 6397 in the visible and I bands with WFPC-2 on the HST. AT a level which is severely limited by counting statistics in the small area so far studied, this field is richer in dwarfs with I > 21.5 than the 4.6' radius parallel field discussed by Paresce and colleagues. This …
ISOCAM CVF observations of the Quintuplet and Object#17 clusters near the Galactic Center.
Kawara, K.; Onaka, T.; Okuda, H. +2 more
Two fields near the Galactic Center, containing the Quintuplet and Object #17 star-clusters, have been imaged with the ISOCAM circular variable filters (CVFs) in the wavelength range of 2.47-3.08µm and 3.99-9.09µm. Emission of [Ar II] 6.99µm is detected in the "pistol-shaped" H II region (G0.15-0.05) to the south of the Quintuple…
The equatorial boundary of the ultraviolet Jovian north aurora observed with multispectral Hubble Space Telescope images
Grodent, D.; Dols, V.; Gérard, J. C. +1 more
Multispectral observations of the far ultraviolet Jovian aurora with the faint object camera (FOC) on board the Hubble Space Telescope are reported. They are used to describe and compare the morphology and the mean brightness of the H2 Lyman and Werner bands observed at 153, 125, and 130 nm. It is shown that most of the emissions are co…
The Spatial Intensity Distribution of the UV Light in HH Objects. Revisited
Raga, A. C.; Noriega-Crespo, A.; Moro-Martin, A. +1 more
Simple kinematical bow shock models have successfully explained many of the observed features in Herbig-Haro objects. It is shown that similar models can be applied to the spatial intensity distribution of the UV lines observed by IUE. Archival IUE spectra have been used for the HH 1, HH 2(H+A'), HH 2(G+B), HH 24A, HH 32A, HH 43(A+B+C),…
The Polarization of X-Ray Binaries in the Ultraviolet. I. Cygnus XR-1, 4U 0900-40, and 4U 1700-37
Boyd, Patricia T.; van Citters, G. W.; Taylor, M. +5 more
Cyg XR-1, 4U 0900 - 40, and 4U 1700 - 37 were monitored polarimetrically and photometrically in the ultraviolet (UV) with the High Speed Photometer (HSP) on the Hubble Space Telescope (HST) at 6-10 different phases during a single binary orbit. Polarimetric observations were obtained in a bandpass centered at 2770 Å; 4U 0900-40 was also monitored …
Interplanetary discontinuities in corotating streams and their interaction regions.
Balogh, A.; Tsurutani, B. T.; Goldstein, B. E. +3 more
In this study, we investigate the discontinuity properties in the low latitude corotating stream regions which are encountered during Ulysses traveling from the south to north heliographic poles in 1995. Through the occurrence rates of directional discontinuities and tangential discontinuities, we find that there are three different regions around…
Proper motion study of the globular cluster M 92.
Tucholke, H. -J.; Scholz, R. -D.; Brosche, P.
We present proper motions for stars in the field of the galactic globular cluster NGC6341 (M92). This study continues the series of papers from the Bonn programme of globular cluster proper motions. Plates taken with the Bonn double refractor and the Rozhen observatory 2m Ritchey-Chretien telescope with a maximal epoch difference of 94years were u…
High Signal-to-Noise Ratio Observations of Weak Interstellar Absorption Lines Towards XI Ophiuchi With the Goddard High-Resolution Spectrograph Aboard the Hubble Space Telescope
Savage, B. D.; Ebbets, D. C.; Carpenter, K. G. +18 more
We present an atlas and tabulation of weak interstellar absorption lines in the ultraviolet spectrum of ζ Ophiuchi in four selected wavelength regions observed with the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. The signal-to-noise ratio ranges from 150 to nearly 400, and the spectral resolving power exceeds 20 000, al…
ROSAT PSPC Observations of the Intermediate Polar TV Columbae
Raymond, J. C.; Primini, F.; Vrtilek, S. D. +1 more
The intermediate polar TV Columbae was observed for 8640s with the ROSAT PSPC. The best-fitting model to the 0.1-2.0 keV spectrum combines a power law with photon index α = 0.82 and a 54 eV blackbody, both observed through a column density of 4.6 x 1020 cm-2. No evidence is seen for line emission from the Fe L-shell complex. …
On the Importance of Dust in Cometary Nuclei
Keller, H. U.; Kührt, E. K.
The icy conglomerate model introduced by Whipple more than 40 years ago has been widely accepted in cometary science because it is able to describe numerous cometary phenomena. In this model comets are described as a conglomerate of ices and dust where the ices represent the major component. However, some recent observations seem to favour dust ri…