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Short term H-alpha variations in two Herbig PMS stars : HR 5999 and HD 52721.
Catala, C.; The, P. S.; Tjin A Djie, H. R. E. +2 more
We present high spectral resolution observations of Hα as well as V photometry and IUE observations for two Herbig pre-main sequence stars, HR 5999 and HD 52721. These observations, performed in 1985, were aimed at studying short-term variations of the Hα line, within one night and from night to night. Hα spectra of comparison stars are also displ…
IUE Spectra of the Eclipsing Binary NN Serpentis
Wood, Janet H.; Marsh, Thomas R.
Low-resolution SWP and LWP IUE spectra are used to fit the temperature and angular radius of the white dwarf in the detached eclipsing binary NN Ser. It is found that the redenning to the system has E(B-V) of 0.05 +/-0.05, the white dwarf temperature is 60,000 +/-10,000 K, and the age of the white dwarf is less than 10 exp 7. The shape of eclipse …
Energy Distributions of Symbiotic Novae
Kwok, Sun; Bryan, Greg L.
The IRAS low-resolution spectra of three recent symbiotic novae are fitted with a dust continuum radiative transfer model. It is found that the dust shells are detached from the photosphere and that the sizes of the inner radii are correlated with times since outburst. An analysis of the IUE spectra of HM Sge at different epochs suggests that the …
EXOSAT Observations of the X-Ray Source 2S 0114+65
Singh, K. P.; Apparao, Krishna M. V.; Bisht, P.
The Exosat satellite made X-ray observations of the Be star binary system 2S 0114 + 65 on five occasions during the period 1983-1986. Several X-ray flares of a few hours duration were observed. The hardness ratio shows an inverse correlation with intensity, indicating that the intensity variation is due to absorption. This implies density irregula…
Calculation of the new series of the Earth orientation parameters in the HIPPARCOS reference frame.
Vondrak, J.
The succesful lauchch of the HIPPARCOS astrometric satellite by the ESA in August 1989 enables the past observations, obtained by optical astrometry all over the world since the beginning of the century, to be re-reduced in order to get the Earth orientation parameters in a homogeneous and unique celestial reference frame. Completely new algorithm…
Iron Kα lines and the absorption structure of intermediate polars
King, A. R.; Watson, M. G.; Norton, A. J.
The X-ray spectra of Intermediate Polars typically show a large absorbing column density and a strong iron K emission line. Using observations made with EXOSAT and GINGA, we show that the lines probably have a fluorescent origin but that their equivalent widths are too large to be due to fluorescence solely in the material which gives rise to the …
Spectroscopic binary orbits from ultraviolet radial velocities. Paper 8: LZ Cephei (HD 209481)
Stickland, D. J.; Howarth, Ian D.; Koch, R. H. +2 more
We present a study of the double-lined spectroscopic binary LZ Cep based on high-resolution IUE spectra. We determine the radial velocities by using a cross-correlation technique incorporating profile fitting; this allows measurements of velocity separations down to unusually small values. The final velocity curve has a small but significant eccen…
Discovery of a new bright southern QSO.
Wisotzki, L.; Wamstecker, W.; Reimers, D. L.
WithIn the newly started Hamburg/ESO survey for bright southern quasars the low-redshift QSO HE 1029-1401 (z = 0.086) was found by automated search on objective prism plates and subsequently confirmed by slit spectroscopy. With v = 13.86 it is among the three brightest QSOs in the sky and the brightest ever found by optical selection. Broad band o…
NGC 6868 : a merger with dust and extended Ly-alpha emission.
Norgaard-Nielsen, H. U.; Jorgensen, H. E.; Hansen, L.
We present IUE observations of the E2 galaxy NGC 6868 showing extended Lyα emission and a weak UV continuum source which also seems extended. Along the lines of sight to the Lyα clouds the column density of neutral hydrogen must be extremely low. Ground based CCD imaging shows the distribution of interstellar dust and optical emission line gas. Ou…
The X-Ray Cooling Flow in the Cluster of Galaxies around PKS 2354-35
Remillard, Ronald A.; Tuohy, I. R.; Schwartz, Daniel A. +1 more
A position measured with the HEAO 1 Scanning Modulation collimator suggested the group of galaxies surrounding the radio galaxy PKS 2354-35 as the identification of the bright, hard X-ray source 4U 0009 - 33 = 3A 2356 - 341 = 1H 2355 - 350. We confirm this identification with measurements of the position and spatial extent using the EXOSAT CMA det…