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PSR 1820-11 : A binary gamma-ray pulsar
Wu, Mei; Li, Ti-pei
Significant pulsation structure in phase distribution in the 50-6000MeV gamma-rays from the direction of the binary radio pulsar PSR 1820-11 in the COS-B data was obtained using the folding algorithm. Besides the period search, a spatial analysis was Bade and a clear point-like gamma-ray image was found at the pulsar's position.
Time variability of stellar coronal sources observed by EXOSAT
Schmitt, J. H. M. M.; Pallavicini, R.
We present an overview of time variability in stellar coronal sources as observed with the EXOSAT satellite. We focus on M dwarf flare stars and we discuss both quiescent and flaring emission. We also outline recent developments in the modelling of stellar flares.
The MG II H and K Interstellar Lines in the Spectrum of the G-Type Giant HD 156854
Kondo, Y.; Shore, Steven N.; Gurzadian, G. A. +2 more
The results of the measurements and analysis of the IUE observations of the 2800 Mg II doublet in the spectrum of HD 156854, a G9 III star, are presented. The relative power of the magnesium chromosphere, R(Mg) = 0.00001, is in agreement with the known data for giants of the same class. The emission profiles of this doublet present absorption core…
The radiation environment for earth-orbiting astronomical satellites
Tranquille, C.; Daly, E. J.
The near-earth radiation environment consists primarily of geomagnetically trapped and solar flare energetic electrons and protons, together with a component of galactic cosmic rays. These charged particles give rise to a variety of physical effects which can compromise the operation of the sensitive detectors and electronics currently used to mak…
Temperatures of coronae of cool stars, derived from EXOSAT observations
Mewe, R.; Schrijver, C. J.; Lemen, J. R.
We observed the late-type stars Capella, σ2 CrB, λ And, AD Leo, GL494, GL569 and Procyon with different combinations of three instruments aboard EXOSAT : the low-energy channel multiplier array (LE), the medium-energy proportional counters (ME), and the transmission grating spectrometer (TGS). We derive crude temperature information on …
EXOSAT Observations of the Suspected Flare Star BD +48 degrees 1958A
Singh, K. P.; Rao, A. R.; Vahia, M. N.
X-ray observations are reported for the BY Dra variable BD + 48 deg 1958A using the low-energy (LE) and the medium-energy (ME) detectors of Exosat. The star is detected in both the LE and the ME detectors, with some evidence for a long-duration (over 2-hr) X-ray flare. A combined spectral fit to the LE and ME data leads to an X-ray plasma temperat…
Utilization of the Archive Data from EXOSAT
Hang, H. R.; Zang, Z. Y.; Han, H. Y.
A Comparison of the Near Ultraviolet Continuum and Chromospheric Emission Line Fluxes of the Late Type Giant Stars
Avcioglu, Kamuran; Ozkan, M. Turker; Mentese, H. Huseyin
We investigate the near-ultraviolet high-resolution LWR spectra of the stars α Cas, β And, α Tau, β Gem, γ Cru, α Boo, and β Peg, obtained with the aid of the International Ultraviolet Explorer Satellite. We have given here a list of the strongest and most prevalent emission lines in the near-ultraviolet spectra of α Boo, KlIIIp, and β Peg, M2.5II…
Observations of Energetic Water Group Ions E(H2O) > 60 KeV Near the Magnetic Pile-Up Region of Comet Halley Obtained Onboard the Giotto Spacecraft on 13/14 March 1986
Wenzel, K. -P.; Kirsch, E.; O'Sullivan, D. +4 more
Theory of Radiatively Driven Winds of Hot Stars: II. Some Aspects of Radiative Transfer.
Pauldrach, A. W. A.; Puls, J.