Search Publications
Lyman α emission from galaxies: the case of absorption line selected galaxies at z~0.3-0.4.
Buat, V.; Bergeron, J.; Deharveng, J. -M.
Three galaxies, at moderate redshifts (z~0.3-0.4) and identified as causing MgII absorption lines in the spectra of the quasars 0229+131, 1127-145 and 1209+107, have been observed with the Faint Object Spectrograph on-board the Hubble Space Telescope. The spectra have been obtained with the large aperture (4.3x1.4" effective), at a resolution (poi…
V 348 Sagittarii: analysis of the absorption spectrum.
Jeffery, C. S.
The highly variable star V 348Sgr has been variously described as a hot RCrB star, an extreme helium star and a cool Wolf-Rayet ([WC11]) central star of a planetary nebula. Despite the Wolf-Rayet nature of its spectrum, sufficient pure absorption lines are visible to allow the LTE analysis of its photosphere presented in this paper. The weak #1IVλ…
IUE observations of blue horizontal branch stars in the globular clusters M 3 and NGC 6752.
Cacciari, C.; Bragaglia, A.; Fusi Pecci, F. +1 more
IUE observations of 3 blue horizontal branch (BHB) stars in M 3 and 4 stars in NGC 6752 are presented. In addition, unpublished IUE archive data have been used for 5 more BHB stars in NGC 6752. Using the most recent model atmospheres (Kurucz 1992) the physical parameters of these stars have been derived, and compared with the ZAHB evolutionary tra…
A multiwavelength study of the classical nova V4169 Sagittarii.
de Martino, D.; Evans, A.; Rawlings, J. M. C. +8 more
We present multiwavelength observations of V4169 Sgr (Nova Sgr 92#2) from 1000A to 2cm for the first year following visual maximum. V4169 Sgr was an `Fe II' type nova, and evolved from P^0^_fe_ to N_0_ in the Tololo nova classification scheme. The ultraviolet spectrum was very similar to that of nova PW Vul, and the near infra-red spectrum was dom…
TYCHO astrometry from half of the mission
Makarov, V. V.; Pedersen, H.; Lindegren, L. +8 more
The Hipparcos satellite's star mapper gives photon counts in two spectral channels simultaneously, close to Johnson B and V. The transit times and the signal amplitudes for each star across two groups of four slits are derived and used for astrometry and photometry, respectively, and this constitutes the Tycho project. The present paper describes …
ROSAT pointed observations of four X-ray bright DA white dwarfs.
Reimers, D.; Wolff, B.; Jordan, S. +1 more
We present pointed observations of four hot DA white dwarfs with the ROSAT satellite. Measurements with the Position Sensitive Proportional Counter (PSPC) and the Wide Field Camera (WFC) were analyzed in the framework of pure hydrogen model atmospheres. The results fit well into the picture of previous studies that objects between about 20000 and …
Astrometry of minor planets with Hipparcos.
Mignard, F.; Hestroffer, D.; Bec-Borsenberger, A. +1 more
After the processing of 30 months of the observations carried out by Hipparcos it is possible to provide a reliable idea of the astrometric results to be obtained on the 48 minor planets included in the observing programme. Hipparcos observations are one-dimensional measurements of the separation of objects along a precessing scanning circle, thes…
Photometry and Hα observations of the binary system FF Aquarii.
Frasca, A.; Catalano, S.; Marilli, E. +1 more
We report on UBV photometry and moderate resolution Hα spectrophotometry of the evolved binary system FF Aqr (sdOB + G8 III), performed at the Catania Astrophysical Observatory. The spectrophotometric data were collected in 1990 and 1991, while the photometric light curve is based essentially on observations obtained in 1990. The Hα emission line …
Extended wings of the UV SI IV, C IV resonance doublets and the complex [Fe II] profiles in P Cygni.
Israelian, G.
We investigate the formation and the nature of the extended wings of the UV resonance lines of Si IV 1394, 1402A and C IV 1548 and 1550A in the spectrum of the LBV P Cyg. The effects of line blending in the neighbourhood of these lines were estimated by means of a grid of theoretical synthetic spectra, computed for the P Cyg model atmosphere. It i…
Meridian circle reductions using preliminary HIPPARCOS positions.
Lindegren, L.; Mignard, F.; van Leeuwen, F. +7 more
New reductions of differential observations made by the Bordeaux and La Palma automatic meridian circles have been undertaken, replacing the positions of the FK5 reference stars by those in the Hipparcos 18-month intermediate solution. A remarkable improvement in the post-fit residuals of the classical least-squares adjustment is obtained for both…