Search Publications
Ultraviolet spectral evolution of star clusters in the IUE library.
Alloin, D.; Bonatto, C.; Bica, E.
The ultraviolet integrated spectra of star clusters and H II regions in the IUE library have been classified into groups based on their spectral appearance, as well as on age and metallicity information from other studies. We have coadded the spectra in these groups according to their S/N ratio, creating a library of template spectra for future ap…
The field horizontal-branch B-type star Feige 86.
Bonifacio, P.; Hack, M.; Castelli, F.
IUE and visible high resolution spectra of the halo B-type star Feige 86 are analyzed with the aim to get further insight into the atmospheric parameters and surface chemical composition of this Pop II star. The analysis is mostly based on the comparison of photometric, spectrophotometric, and spectroscopic observations with color indices, fluxes,…
Automated classification of IUE low-dispersion spectra. I. Normal stars.
Ponz, J. D.; Vieira, E. F.
Along the life of the IUE project, a large archive with spectral data has been generated, requiring automated classification methods to be analyzed in an objective form. Previous automated classification methods used with IUE spectra were based on multivariate statistics. In this paper, we compare two classification methods that can be directly ap…
Chemical abundances of southern symbiotic stars.
Pereira, C. B.
Allen's (1984) optical spectra of symbiotic stars were used in order to derive some elemental ratios and He abundances. The studied systems were those for which spectrophotometry was available in his catalogue, i.e. LMC S63, Y Cra, SS 29, He2-104, SS 38, He2-106, V455 Sco, He2-127, He2-171, AE Ara, SS 122 and Hen 1242 (=KX TrA). Estimates for the …
A search for wind variability in central stars of planetary nebulae.
Patriarchi, P.; Perinotto, M.
All the high resolution spectra of central stars of Planetary Nebulae (CSPN) obtained so far with the SWP camera of the IUE satellite have been examined for variability in their P Cygni profiles. The available data allowed to explore the constancy or changes of the line profiles in fourteen CSPN over time scales of months to various years. In nine…
Multifrequency monitoring of RU Lupi. I. Observations.
Rossi, C.; Giovannelli, F.; Vittone, A. A. +7 more
In this paper we present the results of a long campaign of coordinated (sometimes simultaneous) multifrequency observations, from X-ray to radio wavelengths of the extreme T Tauri star RU Lupi. The large amount of data obtained can be useful to understanding the physics governing the intriguing behaviour of this pre-main-sequence star. In particul…
Li I 6708 in normal A and F-type stars.
Castelli, F.; Gerbaldi, M.; Faraggiana, R.
The 6708 A Li region has been observed in a sample of unevolved stars of spectral type A-early F and the Li abundances have been determined by using the synthetic spectrum method. As the intensity of the Li I 6708 doublet decreases rapidly with increasing T_eff_ in these stars, we have to pay special attention to the list of lines present in the v…
The UV properties of normal galaxies. II. The ``non-IUE'' data.
Longo, G.; Capaccioli, M.; Rifatto, A.
In the last decade several satellite and balloon borne experiments have collected a large number of ultraviolet fluxes of normal galaxies measured through apertures of various sizes and shapes. We have homogenized this data set by deriving scale corrections with respect to IUE. In a forthcoming paper these data will be used to derive standard lumi…
The ultraviolet spectrum of η Carinae. II. 1980 IUE observations of the Homunculus.
Baratta, G. B.; Viotti, R.; Cassatella, A.
We analyze the ultraviolet observations of the circumstellar nebula of η Car (the Homunculus) obtained in December 1980 with IUE. A high resolution spectrum was obtained with the IUE large aperture from 6" to 17" NW of η Car, near the H condensation (the head). The measured flux appears two orders of magnitude larger than that expected from the in…