Search Publications
A Test for the Nature of the Type IA Supernova Explosion Mechanism
Pinto, Philip A.; Eastman, Ronald G.; Rogers, Tamara
Currently, popular models for Type Ia supernovae (SNe Ia) fall into two general classes. The first comprises explosions of nearly pure carbon/oxygen (C/O) white dwarfs (WDs) at the Chandrasekhar limit which ignite near their centers. The second consists of lower mass C/O cores which are ignited by the detonation of an accreted surface helium layer…
Understanding the atmospheric structure of T Tauri stars - II. UV spectroscopy of RY Tau, BP Tau, RU Lupi, GW Ori and CV Cha
Lanzafame, A. C.; Brooks, D. H.; Costa, V. M. +1 more
We report results from our study of International Ultraviolet Explorer (IUE) data of a group of T Tauri stars (TTS). Comparisons between UV-line fluxes in these stars and in the Sun indicate very high levels of activity in their atmospheres and comparatively higher electron densities. Spectroscopic diagnostic line ratios indicate densities over an…
CCD photometry and astrometry for visual double and multiple stars of the HIPPARCOS catalogue III. CCD photometry and differential astrometry for 253 southern ``intermediate'' systems
Lampens, P.; Oblak, E.; Duval, D. +1 more
We present new astrometric and photometric data for 253 visual double stars of the ``intermediate'' class, i.e. with angular separations in the range 1 to 15 arcsec. The multi-colour observations were obtained in 1992-94 as part of the ESO Key Programme ``Visual Double Stars'' performed at La Silla Observatory (Chile). Differential magnitudes and …
Coronal restructuring and electron acceleration following a filament eruption
Klein, K. -L.; Marqué, Ch.; Lantos, P. +1 more
We present a multi wavelength observation of a filament eruption occurring on September 2nd 1999. The slow pre-event evolution of the filament ends with energy release signaled by a faint radio burst observed with the Nançay Radioheliograph and a faint LDE. The restructuring of a large area around the site of the eruption was monitored both with S…
An ISO investigation of the MWC 297 circumstellar region
Benedettini, M.; Pezzuto, S.; Lorenzetti, D. +2 more
The ISO-SWS full grating spectrum (2.3-45 mu m) of the Herbig Be star MWC 297 is presented. The spectrum is dominated by a strong continuum with superimposed emission lines and features both in absorption and in emission. In particular, we detect in emission 23 H I recombination, lines of the Brackett, Pfund and Humphreys series and four PAH featu…
Coordinated ground-based, low altitude satellite and Cluster observations on global and local scales during a transient post-noon sector excursion of the magnetospheric cusp
Orsini, S.; Pitout, F.; Balogh, A. +56 more
On 14 January 2001, the four Cluster spacecraft passed through the northern magnetospheric mantle in close conjunction to the EISCAT Svalbard Radar (ESR) and approached the post-noon dayside magnetopause over Green-land between 13:00 and 14:00 UT. During that interval, a sudden reorganisation of the high-latitude dayside convection pattern occurre…
Dynamics of a Quiescent Solar Prominence Observed with the SUMER/SOHO Instrument
Bocchialini, K.; Rovira, M.; Costa, A. +3 more
We present the results obtained from analyzing SUMER/SOHO observational data of a quiescent solar prominence. The studied prominence is made of complex structures. From the 1-hr data set, we derive characteristic frequencies in terms of intensity and velocity oscillations, as measured in 4 transition-region lines. The presence of different types o…
A Multivariate Analysis of Galaxies in the Hubble Deep Field-North
Thompson, Rodger I.; Corbin, Michael R.; Stobie, Elizabeth +2 more
We use the ultraviolet and optical WFPC2 and near-infrared NICMOS images of the Hubble Deep Field-North to measure and statistically compare an array of parameters for over 250 of the galaxies it contains. These parameters include redshift, rest-frame visible asymmetry and concentration, bolometric luminosity, and extinction-corrected star formati…
Observations of two complete substorm cycles during the Cassini Earth swing-by: Cassini magnetometer data in a global context
Kurth, W. S.; McComas, D. J.; Lester, M. +13 more
During the Earth swing-by of the Cassini spacecraft, a worldwide program of data-gathering was undertaken to define the prevailing interplanetary and geophysical conditions. This included observations of the interplanetary medium, outer magnetosphere, geostationary orbit, UV aurora, geomagnetic disturbance, and ionospheric flow. These data show th…
SPIRAL Phase A: A Prototype Integral Field Spectrograph for the Anglo-AustralianTelescope
Kenworthy, Matthew A.; Taylor, Keith; Parry, Ian R.
We present details of a prototype fiber feed for use on the Anglo-Australian Telescope (AAT) that uses a dedicated fiber-fed medium/high-resolution (R~=10,000) visible-band spectrograph to give integral field spectroscopy (IFS) of an extended object. A focal reducer couples light from the telescope to the close-packed lenslet array and fiber feed,…