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Dense Spot Coverage and Polar Caps on SV Cam
Jeffers, S. V.; Barnes, J. R.; Aufdenberg, J. P. +1 more
We have used spectrophotometric data from nine Hubble Space Telescope orbits to eclipse-map the primary component of the RS CVn binary SV Cam. From these observations and its HIPPARCOS parallax we find that the surface flux in the eclipsed low-latitude region is about 30 % lower than computed from the best fitting PHOENIX model atmosphere. This fl…
``The ESA XMM-Newton Science Operations Centre: Making Basic Space Science Available to the Whole Scientific World''
Metcalfe, Leo; Guainazzi, Matteo; Gabriel, Carlos
XMM-Newton is a major X-ray observatory of the European Space Agency (ESA). Its observing time is open to astronomers from the whole scientific community on a peer reviewed competitive basis. The Science Operations Centre, located at ESA's premises in Villafranca del Castillo, Spain, is responsible for the instrument operations, as well as for all…
Ultraviolet Studies Of Interacting Binaries
Shore, Steven N.; Long, Knox S.; Marsh, Thomas R. +4 more
Interacting Binaries consist of a variety of stellar objects in different stages of evolution and those containing accreting compact objects still represent a major challenge to our understanding of not only close binary evolution but also of the chemical evolution of the Galaxy. These end-points of binary star evolution are ideal laboratories for…
Stochastic Acceleration of Energetic Particles in the Magnetosphere of Saturn
Martínez-Gómez, E.; Durand-Manterola, H. J.; Tejada, H. Pérez de
Voyager's plasma probe observations suggest that there are at least three fundamentally different plasma regimes in Saturn: the hot outer magnetosphere, the extended plasma sheet, and the inner plasma torus. At the outer regions of the inner torus some ions have been accelerated to reach energies of the order of 43 keV. We develop a model that cal…
Starbursts at space ultraviolet wavelengths
González Delgado, Rosa M.
Starbursts are systems with very high star formation rate per unit area. They are the preferred place where massive stars form; the main source of thermal and mechanical heating in the interstellar medium, and the factory where the heavy elements form. Thus, starbursts play an important role in the origin and evolution of galaxies. The similaritie…
Late-type X-ray Emitting Binaries in the Solar Neighborhood and in Star Forming Regions
Alcalá, Juan M.; Covino, Elvira; Frasca, Antonio +3 more
We present a spectroscopic and photometric follow-up of binary stars, discovered in a sample of X-ray sources, aimed at a deep characterization of the stellar X-ray population in the solar neighborhood and in Star Forming Regions (SFRs). The sources have been selected from the RasTyc sample, obtained by the cross-correlation between the ROSAT all-…
The Spatial Distribution of W UMa-Type Stars
Ogloza, Waldemar; Zakrzewski, Bartlomiej
The aim of this project is to study the spatial distribution of contact binaries and to compare the sample from the project of study the W UMa-type stars, with existing databases such as Hipparcos, GCVS or ASAS (ESA, 1997; GCVS, 2005; Pojmanski, 2002).
Pulsar Wind Nebulae in Egret Error Boxes
Hessels, Jason W. T.; Ng, C. -Y.; Gaensler, Bryan M. +3 more
A remarkable number of pulsar wind nebulae (PWN) are coincident with EGRET γ-ray sources. X-ray and radio imaging studies of unidentified EGRET sources have resulted in the discovery of at least six new pulsar wind nebulae (PWN). Stationary PWN (SPWN) appear to be associated with steady EGRET sources with hard spectra, typical for γ-ray pulsars. T…
Location and parameters of a microwave millisecond spike event
Nakajima, Hiroshi; Huang, Guangli
A typical microwave millisecond spike event on November 2, 1997 was observed by the radio spectrograph of National Astronomical Observatories (NAOs) at 2.6–3.8 GHz with high time and frequency resolution. This event was also recorded by Nobeyama Radio Polarimeters (NoRP) at 1–35 GHz and Radio Heliograph (NoRH) at 17 GHz. The source at 17 GHz is lo…
UX Ret and CN Hyi: hipparcos photometry analysis
Wadhwa, Surjit S.; Zealey, William J.
We present an analysis of the Hipparcos photometry of the contact binary systems UX Ret and CN Hyi. The Wilson-Devinney code is employed to model the V band light curve for several fixed values of the mass ratio. From the quality-of-fit of the different solutions a final solution is derived for each system. Absolute values of the system are derive…