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Reprocessing the Hipparcos data for evolved giant stars II. Absolute magnitudes for the R-type carbon stars
Jorissen, A.; Pourbaix, D.; Knapp, G.
The Hipparcos Intermediate Astrometric Data for carbon stars have been reprocessed using an algorithm which provides an objective criterion for rejecting anomalous data points and constrains the parallax to be positive. New parallax solutions have been derived for 317 cool carbon stars, mostly of types R and N. In this paper we discuss the results…
A Search for Signatures of Quasar Evolution: Comparison of the Shapes of the Rest-Frame Optical/Ultraviolet Continua of Quasars at z>3 and z~0.1
Elvis, Martin; Bechtold, Jill; Elston, Richard +1 more
For 15 bright (V<17.5), high-redshift (z>3) quasars, we have obtained infrared spectra and photometry, and optical spectrophotometry and photometry, which we use to construct their spectral energy distributions (SEDs) from λrest~1285-5100 Å. High-resolution spectroscopy for seven enable measurements of their continua shortward of …
Cluster magnetic field observations of the bowshock: Orientation, motion and structure
Balogh, A.; Horbury, T. S.; Lucek, E. A. +7 more
Four spacecraft Cluster magnetic field observations of the low <beta> quasi-perpendicular terrestrial bowshock are presented for the first time. Multiple quasi-perpendicular crossings on 25 December 2000 are analysed. By combining data from the four spacecraft, bowshock orientations and velocities can be calculated. It is shown that, even wh…
The X-Ray Afterglow of GRB 000926 Observed by BeppoSAX and Chandra: A Mildly Collimated Fireball in a Dense Medium?
Piro, L.; Antonelli, L. A.; Frail, D. A. +8 more
We present X-ray observations of the afterglow of GRB 000926, performed around and after the break observed in the optical light curve 2 days after the burst. The steep X-ray light curve observed around the break confirms the presence of this feature in X-rays. However, the spectral and temporal properties are not consistent with a standard jet sc…
Infrared spectrum and proper motion of the brown dwarf companion of HR 7329 in Tucanae
Neuhäuser, R.; Guenther, E. W.; Huélamo, N. +2 more
Up to now only four brown dwarf companions to normal stars have been found and confirmed by both spectroscopy and proper motion (namely
Broadband infrared photometry of comet Hale-Bopp with ISOPHOT
Krüger, H.; Lamy, P.; Keller, H. U. +21 more
Comet Hale-Bopp was observed five times with ISOPHOT, the photometer on board ESA's Infrared Space Observatory (ISO) between 4.6 and 2.8 AU. Each time, broadband photometry was performed using 4 different detectors, 5 apertures and 10 filters covering the range between 3.6 and 170 mu m. Background observations were performed with identical instrum…
Water in K and M giant stars unveiled by ISO
Tsuji, T.
Based on the spectra obtained with Infrared Space Observatory, ISO, we detected the 6.3 mu m bands of water in the late K giant Aldebaran (alpha Tau) and several early M giant stars (between M0 and M3.5), which have been deemed to be too warm for tri-atomic H2O molecule to reside in their photospheres. The water column densities range (…
SCUBA photometry of candidate Vega-like sources
Barlow, M. J.; Sylvester, R. J.; Dunkin, S. K.
New SCUBA measurements at millimetre wavelengths are presented for a sample of Vega-like stars. Six stars were detected, while sensitive upper limits were obtained for a further 11 sources. Most of the sample selected from a recent catalogue of Vega-like stars have infrared excesses similar to those of the prototype Vega-like stars α Lyr and α PsA…
Bands of solid CO2 in the 2-3 mu m spectrum of S 140:IRS1
Schutte, W. A.; Tielens, A. G. G. M.; Boogert, A. C. A. +2 more
We investigate the 2-3 µm ISO-SWS spectrum of the luminous protostellar object S 140:IRS1. Two narrow absorption features are detected at 2.70 and 2.77 mu m, which are well fitted with laboratory spectra of the nu1 + nu3 and the 2nu2 + nu3 combination modes of solid CO2. The ice in this …
Boron Abundances in Early B Stars: Results from the B III Resonance Line in IUE Data
Proffitt, Charles R.; Quigley, Mark F.
We have used archival International Ultraviolet Explorer high-dispersion SWP spectra to study the B III resonance line at 2065.8 Å in 44 early B stars. We find a median boron abundance about half that of solar system meteoritic material, consistent with the values found from previous studies of boron in early B stars. About one-third of the stars …