Search Publications
ISO observations of the GRB 970402 error box
Altieri, B.; Palazzi, E.; Frontera, F. +12 more
Following the detection by BeppoSAX of GRB 970402, a Target-of-Opportunity Observation by ISO was scheduled for 5 April, about 55-hours after the event, i.e. simultaneous with a second BeppoSAX pointing. The CAM instrument was used in the 6('') /pixel mode, in the 8-15 mu m band (IRAS) for covering the entire BeppoSAX GRB error box. A further obse…
A Possible Companion to Proxima Centauri
Benedict, G. F.; Franz, O. G.; Bruhweiler, F. C. +10 more
We report Hubble Space Telescope observations that provide evidence for a companion to Proxima Centauri (Gl 551), the closest star to the Sun. Data acquired with the Faint Object Spectrograph (FOS), used as a coronagraphic camera, show excess light that can be interpreted as being from a substellar object within 0.5" of Proxima Cen. Two observatio…
Discovery of a 6.4 Micron Dust Feature in Hydrogen-Poor Planetary Nebulae
Borkowski, Kazimierz J.; Bregman, Jesse D.; Tsvetanov, Zlatan I. +2 more
Hydrogen-poor planetary nebulae (PNe) Abell 58, Abell 78, and IRAS 15154-5258 were observed with the ISOPHOT low-resolution spectrometer on board the Infrared Space Observatory. Polycyclic aromatic hydrocarbon (PAH) features, commonly seen in H II regions, PNe, and in the diffuse interstellar medium, are absent from their infrared (IR) spectra. A …
IUE high-resolution observations of the symbiotic star CHCygni: confirmation of the triple-star model
Bode, M. F.; Drechsel, H.; Skopal, A. +1 more
We present and analyse ultraviolet high-resolution spectra of CHCyg taken during the whole period of the International Ultraviolet Exploler (IUE) mission. Our analysis of the observed variation in the line spectrum confirms a triple-star model recently suggested for CHCyg. Radial velocities of emission lines, which are subject to eclipse in the sy…
The Close Magnetic/Nonmagnetic Double-degenerate Binary LB 11146
Liebert, James; Schmidt, Gary D.; Smith, Paul S.
Spacecraft imaging of the remarkable strongly magnetic/nonmagnetic white dwarf binary system LB 11146 establishes an upper limit to the component separation of 0.025", corresponding to a 90% likelihood that the orbital separation is a < 500 R_⊙. The large and nearly identical inferred masses for the two components make it very likely that some …
Simultaneous Hubble Space Telescope/Rossi X-Ray Timing Explorer Observations of Scorpius X-1
Kallman, T.; Boroson, B.; Vrtilek, S. D.
Scorpius X-1 is the brightest extrasolar point source of X-rays and may serve as a prototype for low-mass X-ray binaries as a class. It has been suggested that the UV and optical emission arise as a result of reprocessing of X-rays and that a likely site for such reprocessing is an accretion disk around the X-ray source. If UV and optical emission…
Time-correlation of the solar p-mode velocity signal from GOLF
Roca Cortes, T.; Ulrich, R. K.; Grec, G. +5 more
Since the launch of SOHO, the Solar Heliospheric Orbital Observatory, the helioseismic observations are nearly uninterrupted. The GOLF instrument (A. Gabriel et al., 1997) measures the mean velocity integrated over the disk. The autocorrelation function of this velocity shows two main features: Firstly, the initial decrease of the peak amplitudes …
The X-ray jet in the merging galaxy system Markarian 266
Kollatschny, W.; Kowatsch, P.
We present deep ROSAT X-ray images of the double nucleus galaxy Mrk 266 in combination with optical images and spectra. The High Resolution Imager (HRI) X-ray morphology can be divided into four components: two nuclei of the merging galaxies, a diffuse galactic component and a strong northern jet coincident with very strong optical line emission. …
Quasi-periodic behavior of ion events and wave activity upstream from Jupiter's Bow Shock: Ulysses' observations
Balogh, A.; Sarris, E. T.; Anagnostopoulos, G. C. +3 more
A new insight into the ways that the Jovian magnetosphere influences the near Jupiter interplanetary space becomes possible thanks to Ulysses' collection of magnetic field, plasma and energetic ion (HI-SCALE) data during its inbound trajectory (d22-d34, 1992). The most striking new results from the analysis of those data are the following: a) pres…
The Search for Solar Gravity-Mode Oscillations in the Solar Wind Using it Ulysses Plasma Data
Riley, Pete; Hoogeveen, Gary W.
A recent report that energetic particles measured in the solar wind may be influenced by solar gravity-mode (-mode) oscillations motivated the search for -mode signatures in the Ulysses solar wind plasma data. Ulysses solar wind plasma data from 1 March 1992 through the 12 April 1996 were examined in this study for signs of possible solar oscillat…