Search Publications
Missions
Journals
Publication Years
The large-scale distribution of X-ray active stars
Schmitt, J. H. M. M.; Motch, C.; Guillout, P. +4 more
We analyse the large-scale sky distribution of 8593 X-ray emitting stars from the cross-correlation of the ROSAT All-Sky Survey sources with the Tycho catalog. We detect a density gradient from the galactic plane to the galactic pole which is attributed to the scale height of the young late type star population of the galactic disc. The data also …
Goddard High-Resolution Spectrograph Observations of Cool Low-Gravity Stars. IV. A Comparison of the K5 III stars α Tauri and γ Draconis
Brown, Alexander; Robinson, Richard D.; Carpenter, Kenneth G.
The Goddard High-Resolution Spectrograph (GHRS) has observed the K5 III star α Tau in the 2330 Å region on three separate occasions. These spectra show marked changes with time, with the UV continuum varying by a factor of 2, and with the emission lines changing in flux by 30% or more, with the amount of change dependent upon the opacity of the li…
The Cassini CAPS Electron Spectrometer
Coates, A. J.; Linder, D. R.; Grande, M. +6 more
One of the major aims of the Cassini spacecraft is to characterize in detail the interaction of the solar wind with the Saturnian system. The Cassini Plasma Spectrometer (CAPS) addresses this aim by measuring the plasma particles, ions and electrons, with a suite of three complementary sensors. One of these, the Electron Spectrometer (ELS), will m…
On the mass-loss of PG1159 stars
Rauch, T.; Dreizler, S.; Koesterke, L.
The winds of the four PG1159 stars NGC7094, NGC246, K1-16 and RXJ2117.1+3412 are investigated by means of non-LTE models for spherically expanding atmospheres. Based on the results of recent plane-parallel non-LTE analyses, several individual models with various mass-loss rates are calculated. Synthetic profiles of the C Iv resonance line are comp…
Detection of the ``44 MU m'' band of water ice in absorption in combined ISO SWS-LWS spectra
Heras, A. M.; Tielens, A. G. G. M.; Cox, P. +8 more
We report the detection of the transverse optical vibrational band of water ice at 44 microns in absorption towards two embedded infrared sources, IRAS 18316-0602 (RAFGL7009S) and IRAS 19110+1045. The water band extending from 30 to about 80 microns is a prominent feature in the combined ISO SWS and LWS grating spectra. Using new optical constants…
Cygnus A: stars, dust and cones
Sparks, William B.; Tadhunter, Clive; Jackson, Neal
We present new Hubble Space Telescope (HST) continuum and spectral line images of the radio galaxy Cygnus A. The images show much complex structure in the central kpc^2. Continuum images show the central dust lane in detail, allowing detailed maps of E(B-V) to be constructed; the dust appears to follow a roughly Galactic extinction law. The emissi…
CO observations and mass loss of MS- and S-stars
Groenewegen, M. A. T.; de Jong, T.
We present (12) CO J = 1-0 and 2-1 observations of 14 S-stars, and report 6 new detections. Two stars were observed in the (13) CO J = 1-0 and 2-1 lines, and one tentative 2-1 detection is reported. A compilation is presented of all CO observations of S-stars. The stars in this sample are separated into ``intrinsic'' and ``extrinsic'' S-stars, bas…
Observations of Coronal Structures Above an Active Region by EIT and Implications for Coronal Energy Deposition
Michels, D. J.; Thompson, B. J.; Gurman, J. B. +19 more
Solar EUV images recorded by the EUV Imaging Telescope (EIT) on SOHO have been used to evaluate temperature and density as a function of position in two largescale features in the corona observed in the temperature range of 1.0-2.0 MK. Such observations permit estimates of longitudinal temperature gradients (if present) in the corona and, conseque…
Cosmic-Ray 26Al and Its Decay in the Galaxy
Simpson, J. A.; Connell, J. J.
Radioactive 26Al (τ1/2=8.7×105 yr) has been resolved from stable 27Al in the cosmic radiation for the first time using the high mass resolution, charged particle telescope on the Ulysses spacecraft. The average density of the interstellar medium through which the cosmic radiation propagates was determine…
Type III radio source located by Ulysses/Wind triangulation
Kaiser, M. L.; Stone, R. G.; Fainberg, J. +1 more
Radio triangulation from the widely separated Ulysses and Wind spacecraft is used to reconstruct the trajectory of a type III radio burst in the three-dimensional heliosphere. The derived radio trajectory follows a (Parker) spiral path corresponding to a solar wind speed of ~200km/s and progresses to the south of the ecliptic plane. These remote r…