Search Publications
Scattered starlight contamination in the spectrum of reddened stars
Zagury, Frédéric
The comparison, undertaken in preceding papers, of the UV observations of nebulae and of reddened stars reveals contradictory aspects of interstellar extinction. The aim of this paper is to understand the implications hidden behind the apparent contradictions. The questions treated will be: how can small grains with an isotropic phase function mak…
Mg II Emission Lines of Hyades F Stars
Robinson, Richard D.; Carpenter, Kenneth G.; Böhm-Vitense, Erika +1 more
With the Hubble Space Telescope (HST) we have observed Hyades F stars, using the Space Telescope Imaging Spectrograph (STIS), in order to get more information about the heating mechanism(s) for the chromospheres and transition layers and their dependence on rotation and age. In this paper we study the Mg II lines at 2800 Å. We include earlier obse…
Archival HST and IUE Study of the Dwarf Novae AH Herculis and CM Delphini: Exposed White Dwarfs?
Wood, Janet H.; Stys, D.; Sion, E. +2 more
We have analyzed Hubble Space Telescope (HST) archival and IUE NEWSIPS archival SWP spectra of the dwarf novae CM Del and AH Her obtained when AAVSO light-curve data indicated the occurrence of dwarf nova quiescence. We have computed synthetic, high-gravity spectra in LTE with solar composition using TLUSTY195 and SYNSPEC42 and have carried out fi…
Shock Wave Emission at Miller's Position 1 in the Cygnus Loop
Blair, William P.; Raymond, J. C.; Li, J. +1 more
We present the far-UV spectrum (900-1800 Å) of the bright filament known as Miller's (1974) position 1 in the Cygnus Loop obtained with the Hopkins Ultraviolet Telescope during the Astro-2 space shuttle mission. Longer wavelength IUE and ground-based spectra of adjoining regions were scaled to produce a combined spectrum ranging from 900 to 7500 Å…
The milliJansky 12-µm population: first follow-up
Clements, D. L.; Franceschini, A.; Desert, F. -X.
We present the first results of our follow-up programme of optical imaging and spectroscopy of a deep 12-µm survey conducted with the ISO satellite. We find that the objects are typically of fairly low redshift (z~0.1-0.2), but with a tail that extends to high redshifts. The highest redshift object is a previously unknown quasar at z=1.2. Th…
Solar Wind Electron Observations Near Solar Maximum at High Latitudes From Thermal Noise Spectroscopy
Moncuquet, Michel; Issautier, Karine; Meyer-Vernet, Nicole +1 more
The Ulysses spacecraft is reaching high heliolatitudes during the approach to solar maximum. We show preliminary in situ electron observations from the URAP experiment, using thermal noise spectroscopy. This method is especially suited to measure accurately the electron density and thermal temperature. The data acquired in the period June Septembe…
High angular resolution observations in the near infrared and modeling of the peculiar envelope of HD 62623
Danchi, W.; Lopez, B.; Monnier, J. D. +3 more
We report new observations of the peculiar star HD 62623 obtained with aperture masking interferometry performed on the Keck I telescope at lambda = 1.24, 1.65, 2.26 and 3.08 µm. The envelope around this star appears partially resolved in the near infrared except at 1.65 µm. Radiative transfer modeling of the dust shell of this star ha…
IUE and ISO observations of the bipolar proto-planetary nebula Hen 401 (IRAS 10178-5958)
Pottasch, S. R.; de Martino, D.; García-Lario, P. +5 more
We present ultraviolet (IUE) and infrared (ISO) observations of the bipolar proto-planetary nebula Hen 401 which, combined with previously available optical and near infrared data, are used to reconstruct the overall spectral energy distribution from 1150 Å to 100 mu m. The ISO spectrum is dominated by strong PAH emission superimposed on a very co…
Scalar helium magnetometer observations at Cassini Earth swing-by
Dougherty, Michele K.; Russell, Christopher T.; Smith, Edward J. +1 more
When the Cassini spacecraft passed by Earth en route to the outer solar system, the magnetic field magnitude was measured with extremely high accuracy by the onboard helium magnetometer operating in the scalar mode. Magnitude measurements of the near-equatorial field were obtained inbound from 4 to 1.17RE at local times from postnoon to…
HST/NICMOS Observations of M82
Rieke, George H.; Alonso-Herrero, Almudena; Rieke, Marcia J. +1 more
The irregular galaxy M82 is known as the archetypal starburst galaxy. Its proximity (3.5 Mpc) makes this galaxy an ideal laboratory for studying the properties of its starburst. The detailed morphology of the [FeII] 1.644 µm and emission Paα (at 1.87 µm) is revealed by the NICMOS images. The peak of the 2.2 µm continuu…