Search Publications
New variable chemically peculiar stars identified in the HIPPARCOS archive
Paunzen, E.; Maitzen, H. M.
Since variability of chemically peculiar (CP) stars plays an important role for the astrophysical explanation of their outstanding behaviour, we have identified new variable CP stars listed in Renson's catalogue using the extensive Hipparcos Variability Annex. From the 293 objects found, 33 were excluded because they are no CP stars and/or have no…
Infrared spectroscopy of Sakurai's object
Eyres, S. P. S.; Salama, A.; Evans, A. +2 more
We present near (ground-based) and far (ISO) infrared spectroscopy of Sakurai's object. As in the case of the optical spectrum, between 1996 and 1997 April the near-infrared spectrum underwent a dramatic change to later spectral type, and there is some evidence that the spectrum continued to evolve during 1997. Molecular features of carbon-bearing…
The new gravitational lens system B1030+074
Koopmans, L. V. E.; Browne, I. W. A.; Wilkinson, P. N. +6 more
We report the discovery of a new double-image gravitational lens system, B1030+074, which was found during the Jodrell Bank-VLA Astrometric Survey (JVAS). We have collected extensive radio data on the system using the VLA, MERLIN, the EVN and the VLBA, and optical observations using WFPC2 on the HST. The lensed images are separated by 1.56 arcsec …
Solar Wind Consequences of a Coronal Hole Density Profile: Spartan 201-03 Coronagraph and Ulysses Observations from 1.15 Rsolar to 4 AU
Guhathakurta, Madhulika; Fisher, Richard
Spartan 201 is a small shuttle-launched and -retrieved satellite, whose mission is to study the origins of the solar wind. It carries on board two instruments, the Ultraviolet Coronal Spectrometer and the White-Light Coronagraph. The third mission of the Spartan 201 (1995 September 7-10) spacecraft was to provide a solar context for the in situ pa…
HST spatially resolved spectra of the accretion disc and gas stream of the nova-like variable UX Ursae Majoris
Horne, Keith; Hubeny, Ivan; Long, Knox S. +3 more
Time-resolved eclipse spectroscopy of the nova-like variable UX UMa obtained with the HST/FOS on 1994 August and November is analysed with eclipse mapping techniques to produce spatially resolved spectra of its accretion disc and gas stream as a function of distance from the disc centre. The inner accretion disc is characterized by a blue continuu…
The 11B/10B Ratio of Local Interstellar Diffuse Clouds
Sofia, Ulysses J.; Federman, S. R.; Lambert, David L. +3 more
The isotopic ratio 11B/10B of gas in diffuse interstellar clouds toward ζ Oph, κ Ori, and δ Sco is measured using HST/Goddard High Resolution Spectrograph echelle spectra of the B II 1362 Å line. To within the errors of measurement, the three lines of sight give identical results for a mean value of 11B/10
Kinematics of T Tauri stars in Chamaeleon
Brandner, Wolfgang; Covino, Elvira; Frink, Sabine +2 more
We study the kinematics of T Tauri stars (TTS) located in the cores of the Chamaeleon clouds as well as far off these clouds. Our sample comprises 2 early type stars known to be related to Cha i, 6 classical (CTTS) and 6 weak-line T Tauri stars (WTTS) known before the ROSAT mission, and 8 bona-fide pre-main sequence (PMS) stars as well as 23 presu…
Deep radio observations of 3C 324 and 3C 368: evidence for jet-cloud interactions
Carilli, C. L.; Garrington, S. T.; Best, P. N. +2 more
High-resolution, deep radio images are presented for two distant radio galaxies, 3C 324 (z=1.206) and 3C 368 (z=1.132), which are both prime examples of the radio-optical alignment effect seen in powerful radio galaxies with redshifts z>~0.6. Radio observations were made using the Very Large Array in A-array configuration at 5 and 8GHz, and usi…
Anomalous Cosmic Rays
Klecker, B.; Baring, M. G.; Leske, R. A. +22 more
We review the observed properties of anomalous cosmic rays and the present status of our knowledge of the processes by which they originate. We compiled a comprehensive set of ACR energy spectral data from various spacecraft throughout the heliosphere during the passes of Ulysses over the poles of the Sun and present first results of a detailed mo…
Imaging and Spectroscopy of Arcs around the Most Luminous X-Ray Cluster, RX J1347.5-1145
Ferguson, Henry C.; Baum, Stefi A.; Kaiser, Mary Elizabeth +9 more
The cluster RX J1347.5-1145, the most luminous cluster in the X-ray wavelengths, was imaged with the newly installed Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope. Its relatively high redshift (0.451) and luminosity indicate that this is one of the most massive of all known clusters. The STIS images unambiguously …