Search Publications
Quantitative UV spectroscopy of early O stars in the Magellanic Clouds. The determination of the stellar metallicities
Lennon, D. J.; Pauldrach, A. W. A.; Puls, J. +4 more
UV spectra of 4 O-stars in the Magellanic Clouds obtained with the Faint Object Spectrograph of the Hubble Space Telescope are analyzed with respect to metallicity. With the stellar parameters T_eff,log g, R_{*}, and the mass loss rates dot {M} known from optical analyses, the metal abundances including iron group elements are derived in two steps…
The HR-diagram from HIPPARCOS data. Absolute magnitudes and kinematics of BP - AP stars
Luri, X.; Figueras, F.; Royer, F. +5 more
The HR-diagram of about 1000 Bp - Ap stars in the solar neighbourhood has been constructed using astrometric data from Hipparcos satellite as well as photometric and radial velocity data. The LM method \cite{luri95,luri96} allows the use of proper motion and radial velocity data in addition to the trigonometric parallaxes to obtain luminosity cali…
The far infrared line spectrum of the protostar IRAS 16293-2422
Liseau, R.; White, G. J.; Ceccarelli, C. +7 more
We report mid-IR wavelength observations toward the low mass star forming region IRAS 16293-2422 between 45microns - 197microns with the Long Wavelength Spectrometer (LWS) on board ISO, and of the CI(609microns ) line observed with the JCMT. A map of the CII(157microns ) line shows that the region is relatively uncontaminated by Photo-Dissociation…
ISO observations of candidate young brown dwarfs
Torra, J.; Rieke, G. H.; Laureijs, R. J. +2 more
ISOCAM measurements or upper limits for low mass members of the rho Ophiuchi embedded cluster extend the sampling of the spectral energy distributions already obtained from the ground towards longer wavelengths, where emission by circumstellar material is significant. Good fits to the combined (ground-based + ISOCAM) photometry are obtained with t…
Globular clusters in the blue compact galaxy ESO 338-IG04 (Tololo 1924-416), as tracers of the star formation history. Results from HST/WFPC2 observations
Oestlin, Goeran; Bergvall, Nils; Roennback, Jari
Multicolour images of the starbursting metal poor blue compact galaxy ESO 338-IG04 have been obtained with the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. In the images we find numerous point-like sources concentrated towards the main body of the galaxy, which we identify as globular cluster candidates. We show that these ob…
Center-to-limb line width measurements of solar chromospheric, transition region and coronal lines
Doyle, J. G.; Wilhelm, K.; Erdelyi, R. +1 more
Line widths derived from observational data obtained by SUMER onboard SOHO in August 1996 at disk center and at the limb are used to confront those derived via assuming Alfven and/or magneto-acoustic wave heating. The observational data clearly shows a center-to-limb variation in the upper chromospheric and transition region lines, with only a mar…
The absolute magnitude of the early type MK standards from HIPPARCOS parallaxes
Gomez, A. E.; Jaschek, C.
We analyse the standards of the MK system with the help of Hipparcos parallaxes, using only stars for which the error of the absolute magnitude is <= 0.3 mag. We find that the main sequence is a wide band and that, although in general giants and dwarfs have different absolute magnitudes, the separation between luminosity classes V and III is no…
The shock structure in the protoplanetary nebula M1-92: imaging of atomic and H_2 line emission
Sahai, R.; Alcolea, J.; Bujarrabal, V. +2 more
We present HST imaging of continuum (5500 Angstroms) and atomic line (Hα , [OI] 6300 Angstroms, [SII] 6717 and 6731 Angstroms, and [OIII] 5007 Angstroms) emissions in the protoplanetary nebula M 1-92. Ground based imaging of 2$() µm continuum and H_2 ro-vibrational (S(1) v=3D1-0 and v=3D2-1 lines) emission has been also performed. The 5500 A…
Detection of methyl radicals (CH_3) on Saturn
Encrenaz, T.; Feuchtgruber, H.; Moses, J. I. +1 more
We report the first detection of methyl radicals (CH_3) in the upper atmosphere of
HIPPARCOS results on massive X-ray binaries
Chevalier, Claude; Ilovaisky, Sergio A.
We present results on parallaxes, magnitudes and proper motions for 17 optically identified massive X-ray binaries (MXRB) which were observed during the Hipparcos astrometry mission. This sample includes the sources detected in the medium-energy range (2-10 keV) having optical counterparts brighter than V=12. We compare the Hipparcos results with …