Search Publications
Photometric orbit of the massive system RY Sct.
Strazzulla, G.; Milano, L.; Vittone, A. +3 more
The UBV lightcurves of RY Scuti were analyzed using the Wilson and Devinney approach (1971). The system is found to be an evolved overcontact system, embedded in a gas and dust envelope, revealed by forbidden lines and IR excess. It is suggested that RY Scuti has early-type components of 39 and 49 solar masses, making it one of the most massive co…
Further COS-B evidence for gamma-ray emission from 3C273
Caraveo, P. A.; Bignami, G. F.; Hermsen, W. +7 more
The results of a third observation of the Virgo region of the sky by the ESA gamma-ray satellite COS-B are reported. The gamma-ray source (CG291 plus 65) was again seen, and the combined data are analyzed to improve on the position and time-averaged energy spectrum of the source. During the observation, the number of photons from the instrumental …
IUE ultraviolet spectra of the interacting binary U Cep.
Kondo, Y.; McCluskey, G. E., Jr.; Harvel, C. A.
Twenty-one mid-ultraviolet and three far-ultraviolet spectra of the close interacting binary U Cephei have been obtained with the International Ultraviolet Explorer. The results show that the gas stream leaves the G star, circuits around the B companion some 270 deg and leaves the binary system, confirming the preliminary results. Additional sourc…
The ultraviolet spectrum of the normal giant elliptical NGC 4472.
Norgaard-Nielsen, H. U.; Kjaergaard, P.
Low resolution IUE spectra of NGC 4472 covering the wavelength region 1100-3300 Å have been obtained. Strong emission lines have probably been found in the short wavelength region. Such emission lines have also been found in M 31, M 32, and in the nucleus of M 87. Most of the lines can be identified with known chromospheric lines, the relative str…
Galactic γ and radio synchrotron radiation
Osborne, J. L.; Phillipps, S.; Haslam, C. G. T. +2 more
The galactic γ-radiation and radio synchrotron radiation contains information on the distribution of cosmic-ray particles, magnetic field and gas throughout the Galaxy. We report here a new all-sky survey of 408-MHz radio continuum which has been used to compare the distributions of radio and γ-ray emission, with the former convolved to the respon…
Ultraviolet slit spectroscopy in the core of 30 Doradus with the International Ultraviolet Explorer
Koornneef, J.; Mathis, J. S.
Low resolution (about 7 A) IUE observations of the core of the 30 Doradus Nebula in the Large Magellanic Cloud are presented. Data were obtained through the large entrance aperture at 11 different positions in both the long wavelength (1900-3200 A) and short wavelength (1150-2000 A) cameras. The aperture was stepped in 10-arcsec intervals, in the …
A compressed cloud in the VELA supernova remnant
Jenkins, E. B.; Wallerstein, G.; Silk, J. +1 more
Strong interstellar absorption lines of C I, arising from the two excited fine-structure levels, are found in IUE observations of HD 72350 (type B4 III). An analysis of the excited-level populations of C I gives local temperature and pressure limits, and auxiliary data on the limit of column density for excited O I and the carbon ionization help t…
The planetary nebula NGC 7009.
Perinotto, M.; Benvenuti, P.
IUE observations of the planetary nebula NGC 7009 and its central star are presented and used to derive the physical properties of the system. Low-resolution spectra were obtained by the SWP and LWR cameras using the large aperture centered on the nucleus and 6.5 arcsec NE of it. When combined with optical line ratios, the UV data indicate an elec…
On the nebulosities associated with the extreme of star HD 148937.
Gull, T. R.; Bruhweiler, F. C.; Henize, K. G. +1 more
In order to understand the origin of the extreme Of star HD 148937, a study was undertaken of the interrelations between (1) its associated nebulae, including NGC 6164-5, (2) a 2 deg diameter H II region, (3) an outer dust shell, and (4) a newly identified interstellar bubble. A self-consistent model describing the interaction of HD 148937 with th…
TT Ari : a new dwarf nova.
Vogt, N.; Wolf, B.; Drechsel, H. +4 more
The novalike variable TT Ari was observed during the recent remarkable minimum with the IUE on November 17 and 23, 1980, in the low resolution mode in the 1200-3200 A region. The spectrum is characterized by prominent resonance emission lines. A comparison of this spectrum with the spectrum of TT Ari at maximum and with the spectra of dwarf novae …