Search Publications
Lithium Abundance in Pop.II Stars A post-HIPPARCOS discussion
Spite, M.; Hill, V.; Spite, F.
The relation between the lithium abundance observed in Population II stars and the primordial abundance, is still an open question (see Cayrel and Duncan, this meeting). A few recent results are discussed. HIPPARCOS data show that the standard model of stellar evolution can explain the 6Li detection in HD 84937, suggesting a negligible depletion o…
Surface photometry of early-type galaxies in the Hubble deep field
Fasano, G.; Filippi, M.
The detailed surface photometry of a sample of early-type galaxies in the Hubble Deep Field is presented as part of a long-term project aimed to settle strong observational constraints to the theories modelling the evolution of elliptical galaxies from the early stages. The sample has been extracted, in the V606 band, from the database …
New Observations Testing the Adopted HIPPARCOS Link to the International Celestial Reference Frame
Stone, Ronald C.
This paper tests the Hipparcos link to the extragalactic reference frame by using new data obtained after the release of the catalog, thereby providing an external check on the accuracy of the established link process. The new data consist of 689 positions of Hipparcos stars determined in the International Celestial Reference Frame (ICRF) from CCD…
Beta Cephei type variability in the ultraviolet spectrum and radial velocity of PHL 346
Dufton, P. L.; van Leeuwen, F.; Keenan, F. P. +4 more
International Ultraviolet Explorer low-resolution and optical moderate-resolution spectra are presented for the high galactic latitude beta Cephei type star, PHL 346. Variability is identified in both the ultraviolet flux and the radial velocity with periods and phases consistent with those previously deduced from optical photometry. The similarit…
Vega-like Stars: Grain Removal, Replenishment and Recent ISO Observations
Dominik, C.; Hjhvega Consortium
Constraints on Ultraviolet Absorption in the Intracluster Medium of Abell 1030
Koekemoer, Anton M.; Baum, Stefi A.; O'Dea, Christopher P. +3 more
We present results from an extensive Hubble Space Telescope (HST) spectroscopic search for UV absorption lines in the spectrum of the quasar B2 1028+313, which is associated with the central dominant galaxy in the cluster Abell 1030 (z = 0.178). This is one of the brightest known UV continuum sources located in a cluster and therefore provides an …
EUV Full-Sun Imaging and Pointing Calibration of the SOHO Coronal Diagnostic Spectrometer
Thompson, William; Carter, Martin
Although the field of view of the Normal Incidence Spectrometer (NIS) of the Coronal Diagnostic Spectrometer (CDS) is 4×4 arc min, it is possible to observe the full solar disk by forming a mosaic of images taken in succession. This paper describes just such a study which has been used to collect images of the Sun simultaneously in six wavelengths…
Multi-Spacecraft Discontinuity Analysis: Orientation and Motion
Dunlop, Malcolm W.; Woodward, Timothy I.
ISO's View on Massive Star Evolution: Neon Abundances in Wolf-Rayet Stars
Willis, A. J.; Morris, P. W.; van der Hucht, K. A. +1 more
Investigation of the Small-Scale Temperature and Density Fluctuations in Planetary Nebulae through the Use of the ISO Data
Kholtygin, A. F.
The problem of the ne and Te fluctuations in the planetary nebulae (PN) in a view of the ISO data was investigated. The fluxes in the OIII fine structure (FS) lines for a large sample of PNe were estimated.