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Infrared Space Observatory Short Wavelength Spectrometer Observations of V1425 Aquilae (Nova Aquila 1995)
Morisset, C.; Humphreys, R. M.; Gehrz, R. D. +19 more
We present observations of the classical nova V1425 Aquilae (Nova Aquila 1995) with the Infrared Space Observatory's (ISO) Short Wavelength Spectrometer, the Isaac Newton Telescope's Intermediate Dispersion Spectrograph, and the International Ultraviolet Explorer's Short-Wavelength Primary Spectrograph. Analysis of He II (1640 Å) development const…
A relation between dynamics of coronal mass ejections and production of solar energetic particles
St. Cyr, O. C.; Torsti, J.; Kocharov, L. +1 more
During January 1997-June 1998, the Large Angle Spectroscopic Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory spacecraft (SOHO) registered 670 coronal mass ejections (CMEs). We compare two groups of the 300-800 km s-1 CMEs: (i) (very) gradually accelerating CMEs with acceleration below 10;m;s-2, and (ii) impu…
Further indications of a ~140 day recurrence in energetic particle fluxes at 1 and 5 AU from the Sun
Balogh, A.; Dalla, S.; Heber, B. +1 more
A possible ~140 day recurrence in the fluxes and anisotropies of interplanetary MeV energy protons has previously been identified in data from the Anisotropy Telescopes (ATs) on board Ulysses. This measurement was made during 1998-1999 at a distance from the Sun of ~5 AU. Earlier reports of a 154-day periodicity in the occurrence rate of solar fla…
Internal kinematics and binarity of X-ray stars in the Pleiades open cluster
Makarov, V. V.; Robichon, N.
The classical convergent point analysis is implemented for the Pleiades stars with proper motions in the Tycho-2 Catalogue and X-ray fluxes measured by the ROSAT satellite. It is demonstrated that, with the standard astrometric errors as given in Tycho-2, strong X-ray sources in the cluster (log L_X > 29.1, where L_X is in erg s-1) e…
Preprotostellar Core Properties from Far-Infrared Observations
Langer, W. D.; Willacy, K.
We present the results of far-infrared ISOPHOT observations of the preprotostellar cores L1498, B133, and B68. Comparison of the 100 and 200 µm data suggest the presence of two dust temperatures along the line of sight. Using a two-temperature model that assumes a cold central core surrounded by a slightly warmer envelope, we have isolated t…
Kinematics of Hipparcos Visual Binaries. I. Stars with Orbital Solutions
Bartkevicius, A.; Gudas, A.
A sample consisting of 570 binary systems is compiled from several sources of visual binary stars with well-known orbital elements. High-precision trigonometric parallaxes (mean relative error about 5%) and proper motions (mean relative error about 3%) are extracted from the Hipparcos Catalogue or from the reprocessed Hipparcos data. However, 13% …
AGN in the XMM-Newton first-light image as probes for the interstellar medium in the LMC
Pietsch, W.; Haberl, F.; Filipović, M. D. +3 more
The XMM-Newton first-light image revealed X-ray point sources which show heavily absorbed power-law spectra. The spectral indices and the probable identification of a radio counterpart for the brightest source suggest AGN shining through the interstellar gas of the Large Magellanic Cloud (LMC). The column densities derived from the X-ray spectra i…
The Tolman Surface Brightness Test for the Reality of the Expansion. III. Hubble Space Telescope Profile and Surface Brightness Data for Early-Type Galaxies in Three High-Redshift Clusters
Sandage, Allan; Lubin, Lori M.
Photometric data for 34 early-type galaxies in the three high-redshift clusters Cl 1324+3011 (z=0.76), Cl 1604+4304 (z=0.90), and Cl 1604+4321 (z=0.92), observed with the Hubble Space Telescope (HST) and with the Keck 10 m telescopes by Oke, Postman, & Lubin, are analyzed to obtain the photometric parameters of mean surface brightness, magnitu…
Multiwavelength monitoring of QS Tel
de Martino, D.; Buckley, D. A. H.; Howell, S. B. +6 more
Multiwavelength monitoring observations of the AM Her system, QS Tel, are presented, the centrepiece being a coordinated campaign with the ASCA, EUVE and HST satellites and optical observations on 1996 September 28-29. The star was initially observed in an intermediate brightness, single pole state in 1996 April by ROSAT. However two EUVE snapshot…
Investigation of the polytropic relationship between density and temperature within interplanetary coronal mass ejections using numerical simulations
Riley, Pete; Gosling, J. T.; Pizzo, V. J.
Single-point spacecraft measurements within coronal mass ejections (CMEs) often exhibit a negative correlation between electron density and temperature. At least two opposing interpretations have been suggested for this relationship. If, on one hand, these single spacecraft observations provide direct measures of the polytropic properties of the p…