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EXOSAT and Optical Observations of the X-Ray Burst Source 4U/MXB1636-53
Pietsch, W.; van Paradijs, J.; van der Klis, M. +5 more
During May 1984 we made a one-day EXOSAT observation of the X-ray burst source 4U/MXB1636-53, partly simultaneous with Tenma and with optical observations at ESO. In this paper we give a short description of the main results: (i) Discovery of a constant blackbody component in the persistent X-ray emission, with an apparent blackbody radius consist…
Infrared photometry of Seyfert 1.8 and 1.9 galaxies.
Rudy, R. J.; Rodriguez-Espinosa, J. M.
Infrared photometry is reported from 1.25 to 10 micrometers for 10 Seyfert 1.8 and 1.9 galaxies identified by Osterbrock and his collaborators and drawn originally from the Markarian lists. The three objects whose infrared colors are the most nonstellar in nature are objects whose ultraviolet or optical spectra preclude heavy reddening of either t…
H-alpha variability in X-ray transient source X0331+53.
Iye, M.; Kodaira, K.
Spectroscopic observations of X0331+53 between October 1984 and March 1985 revealed that the equivalent width of Hα emission decreased by a factor of about four relative to that observed one year ago. This finding, in association with the decline of X-ray activity of the source reported by the EXOSAT group, is interpreted to support the binary mod…
The Bright Pre-main Sequence Variable HR5999
Talavera, A.; Mewe, R.; Catala, C. +7 more
A meeting to review the reduced coordinated observations by EXOSAT, IUE and ground-based instruments of the bright and variable Herbig A7e star HR 5999 is summarized. The attempt was to delineate the relationship between the various observable quantities of its atmosphere (colors, emission-line fluxes, wind velocities, etc.) in order to develop a …
Observations of RR Lyrae and X ARIETIS with the IUE satellite.
Bonnell, J. T.; Bell, R. A.
UV spectroscopic observations of RR Lyr and X Ari obtained at high and low dispersion using the LWR and SWP cameras of IUE on Jan. 25-28, 1980, are reported. The data are presented in tables and graphs and compared with the results of synthetic-spectrum calculations based on the VR photometric data of Manduca et al. (1981). Good agreement is obtai…
HD 8358 : a new active chromosphere binary.
Ake, T. B.; Bopp, B. W.; Goodrich, B. D. +5 more
The results of an extensive study of the eighth-magnitude G star HD 8358 employing optical photometry and spectroscopy, as well as UV observations with the IUE satellite, are presented. The star is found to be an active chromosphere binary with orbital and photometric period of 0.516 days. It exhibits photometric variability of 0.1-0.2 mg in V, du…
High-dispersion spectroscopy of the eclipse of epsilon Aurigae at visible and ultraviolet wavelengths.
Ferluga, S.; Hack, M.
Visual observations: The authors report some preliminary results of the study of three photographic spectrograms obtained during the ingress, totality and egress phases and compare them with one spectrogram taken before the start of the eclipse. They describe the characteristics of the "shell" spectrum which are similar to those observed during pr…
Emission by OD in comets
A'Hearn, M. F.; Schleicher, D. G.; West, R. A.
A calculation has been made of the complete fluorescent equilibrium of OD in sunlight including ultraviolet (A-X) transitions, vibrational and rotational transitions (A-A and X-X), and Lambda-doubling transitions in the X state. The dependence on heliocentric radial velocity is strong. No lines of OD are visible in any cometary spectra taken with …
Gamma-ray emission from atomic and molecular gas at intermediate galactic latitudes
Strong, A. W.
Recent developments in the study of the correlations between gamma-rays and local gas tracers are described. COS-B data in the range between b of 10 and 20 deg are analyzed using simultaneous 21-cm and galaxy count data, in order to separate the roles of atomic and molecular gas. The new galaxy-count calibration of Strong (1983) is used, and the r…
EXOSAT observations of NGC 1399 and NGC 1404: Two elliptical galaxies in the center of the Fornax cluster
Mason, K. O.; Rosen, S. R.
Imaging X-ray observations of the Fornax cluster of galaxies centered on NGC 1399 and NGC 1404 are presented. NGC 1399 and NGC 1404, which are separated by about 10 arc minutes, are found to have an unusually high ratio of x-ray to optical flux. We consider the possibility that the x-radiation is produced by hot gas in the cores of the galaxies. W…