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Spatially resolved X-ray emission of EQ Pegasi
Schmitt, J. H. M. M.; Ness, J. -U.; Robrade, J.
We present an analysis of an XMM-Newton observation of the M dwarf binary EQ Pegasi with a special focus on the spatial structure of the X-ray emission and the analysis of light curves. Making use of data obtained with EPIC (European Photon Imaging Camera) we were for the first time able to spatially resolve the two components in X-rays and to stu…
Systematic astrometric observations of Proteus
Andrei, A. H.; Veiga, C. H.; Descamps, P. +2 more
Earth based observations of Proteus are made highly difficult by the magnitude difference with Neptune, and the closeness to the planet. To overcome these difficulties, observation campaigns using a Hg-mask coronograph developed for astrometry are being pursued at the Laboratório Nacional de Astrofísica, Brazil. The observations are made at visibl…
Heliospheric energetic particle observations by the Cassini spacecraft: Correlation with 1 AU observations
Livi, S.; Dougherty, M. K.; Lario, D. +3 more
We present energetic particle measurements from the Low-Energy Magnetospheric Measurement System (LEMMS) on board the Cassini spacecraft during its heliospheric cruise to Saturn. We cover 3 years (2000-2002) of data during the maximum of the solar cycle 23. Cassini's heliocentric radial distance ranged from 2.5 to 8.0 AU. Energetic particle intens…
NGC 5385, NGC 2664 and Collinder 21: Three candidate open cluster remnants
Villanova, S.; Carraro, G.; de la Fuente Marcos, R. +1 more
We present CCD UBVI photometric and medium/high resolution spectroscopic observations obtained in the field of the previously unstudied dissolving open cluster candidates NGC 5385, NGC 2664 and Collinder 21. Our analysis is based on the discussion of star counts, photometry, radial velocity distribution, and proper motions available from the Tycho…
MERLIN observations of Stephan's Quintet
Muxlow, T. W. B.; Garrington, S. T.; Xanthopoulos, E. +1 more
We present MERLIN L-band images of the compact galaxy group, Stephan's Quintet (SQ). The Seyfert 2 galaxy, NGC 7319, the brightest member of the compact group, is seen to have a triple radio structure typical of many extra-galactic radio sources that have a flat spectrum core and two steep spectrum lobes with hot spots. The two lobes are asymmetri…
The UV environment of the Beagle 2 landing site: detailed investigations and detection of atmospheric state
Zarnecki, John C.; Cockell, Charles S.; Patel, Manish R. +2 more
December 25th 2003 will see the Beagle 2 lander arrive at the surface of Mars in the Isidis region, allowing for the first time in situ measurements of ultraviolet (UV) flux directly from the surface of Mars through the use of a sensor designed as part of a miniaturised environmental package. The expected conditions the sensor will experience are …
The interaction of comet 153P/Ikeya-Zhang with interplanetary coronal mass ejections: Identification of fast ICME signatures
Brandt, John C.; Jones, Geraint H.
The active comet 153P/Ikeya-Zhang possessed a highly-variable plasma tail. Favorable circumstances allowed the identification of the impact of fast ICMEs with the comet. The impact produces a specific morphology including a characteristic scalloped appearance which suggests that the ICME magnetic field drapes around preexisting tail density enhanc…
Solar latitudinal distortions: From observations to theory
Lefebvre, S.; Rozelot, J. P.
Solar diameters have been measured from different ground-based instruments on different sites all around the world. There are values dating back to three centuries ago, but the revival of interest began in the 1970s when it was claimed that a temporal periodic modulation had been found. The interest of such measurements, pinpointed from only two d…
The Stellar Content of the Polar Rings in the Galaxies NGC 2685 and NGC 4650A
Tikhonov, N. A.; Galazutdinova, O. A.; Hagen-Thorn, V. A. +3 more
We present the results of stellar photometry of polar ring galaxies NGC 2685 and NGC 4650A, using the archival data obtained with the Hubble Space Telescope's Wide Field Planetary Camera 2. Polar rings of these galaxies were resolved into ~800 and ~430 stellar objects in the B, V, and IC bands, a considerable part of which are blue supe…
Soft X-ray heating of the solar chromosphere during the gradual phase of two solar flares
Heinzel, P.; Berlicki, A.
In this paper we perform an analysis of the energetics of the solar flaring chromosphere irradiated by soft X-rays (SXR) emitted from overlying hot flare loops. To study an expected SXR heating we used the observations of two solar flares obtained with the Multichannel Subtractive Double Pass (MSDP) spectrograph attached to the Large Coronagraph o…