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A photometric and spectroscopic study of the association LH47 in the superbubble N44 in the LMC
Bomans, D. J.; Dieball, A.; Will, J. -M.
The OB association LH47 inside the superbubble N44 in the Large Magellanic Cloud (LMC) is analyzed with CCD photometry. For the bright blue stars spectra in the optical and UV have been taken. The observed U, B, and V magnitudes and colours are converted to Teff and L. From isochrone fits to the colour magnitude diagram (CMD), we find a…
Ultraviolet variability of the Seyfert 1 galaxy Fairall 9
Clavel, J.; Rodriguez-Pascual, P. M.; Wamsteker, W. +5 more
The large amplitude of the variations of the Seyfert I Galaxy Fairall-9 between 1978 and 1991 make this Active Galaxy especially suitable for a combined study in terms of reverberation analysis and photoionization modeling over the velocity field of the broad lines of its ultraviolet spectrum. We have combined our ultraviolet data with those avail…
The changes in the UV emission lines of RR Telescopii from 1978 to 1993. I. The IUE SWP region
Hack, M.; Selvelli, P.; Zuccolo, R.
Line emission intensities and FWHMs in the range 1175-1900 Angstroms have been measured on high resolution IUE spectra of RR Tel taken from 1978 to 1993. The variations observed in the emission line intensities show a rather strong correlation with the line ionization. The decrease is of a factor larger than three and up to ten for the low-ionizat…
Wind variability in central stars of planetary nebulae. II.
Patriarchi, P.; Perinotto, M.
New high resolution IUE spectra of central stars of the planetary nebulae (CSPN) NGC 40, NGC 6543, NGC 6826, and BD +30 3639 have been obtained between August 1994 and September 1995 to explore the variability of their P Cygni profiles. The data have been analyzed together with previous observations of the same stars. Significant changes in the pr…
The FUOR characteristics of the PMS star BN Orionis inferred from new spectroscopic and photometric observations
de Winter, D.; van den Ancker, M. E.; Tjin A Djie, H. R. E. +3 more
BN Ori is a young emission-line star with a peculiar light curve. During the first half of this century the star showed strong irregular brightness- variations, similar to those of Herbig Ae stars. In the current half of the century the light curve resembles that of a FU Ori-object (FUOR, after Ambartsumian 1971). It can be characterised by an ini…