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Le premier ciel de Gaia
Arenou, Frederic; Turon, Catherine
On 14 September 2016, the first data release of the ESA's Gaia mission has been published. Based on raw data collected between 25 July 2014 and 16 Septembre 2015, i.e. only over the first 14 months of mission, this first "Gaia sky" includes the accurate positions and Gaia magnitudes of more than a billion objects: it is already the largest all-sky…
Ultraviolet Spectroscopy of BL Hyi and EF Eri in High and Intermediate States
Sanad, M. R.; Abdel-Sabour, M. A.
We present the first phase-resolved ultraviolet spectroscopy of two polar systems, BL Hyi and EF Eri, in high and intermediate states from the International Ultraviolet Explorer (IUE) during the periods between 1982-1995 and 1979-1991, respectively. The flux curves for the C IV and He II emission lines for both systems showing variations in their …
Modern CCD Observations of Selected Minor Planets for the Connection of Dynamic and Kinematic Coordinate Systems
Maigurova, N.; Pomazan, A.
One of the methods of determining the orientation parameters of the dynamic and kinematic coordinate systems is to use of long-term series of ground-based observations of selected asteroids. For achievement of the best accuracy of the link parameters the high precision and uniformly covering the asteroids orbit observations are necessary. The anal…
The vorticity of Solar photospheric flows on the scale of granulation
Pevtsov, A. A.
We employ time sequences of images observed with a G-band filter (λ4305Å) by the Solar Optical Telescope (SOT) on board of Hinode spacecraft at different latitude along solar central meridian to study vorticity of granular flows in quiet Sun areas during deep minimum of solar activity. Using a feature correlation tracking (FCT) technique, we calcu…
The number distribution of weak Explosive Events observed by SUMER/SoHO
Mendoza-Torres, J. E.
Explosive Events (EEs) observed by SUMER on SoHO at the 1393.8 Å Si IV line are analyzed. We look for EEs to study their number distribution at low energies. Eight data sets taken in June 1996 in raster observations are used. In these observations a field on the solar disk is scanned several times during a period considerably longer than the typic…
Introduction: Special issue on planetary rings
Esposito, Larry; Nicholson, Philip
This issue of Icarus is devoted largely to papers presented at an open conference held at the Univ. of Colorado on 13-15 August 2014. This Planetary Rings Workshop is the fourth in a series organized by the Rings Working Group of the Cassini-Huygens mission and most of the papers presented dealt with phenomena revealed
Live Blogging Science News: The Rosetta Mission
Clark, S.
When one of the world's most popular online news websites decides to cover a space science event live, you know that something big is brewing. Stuart Clark reports on how live blogging can be used for science reporting and how an idea that was triggered by his observations during the Rosetta flyby of the asteroid Lutetia and the landing of the Cur…
Observing the Unobservable: Identification and Characterisation of Stealth Coronal Mass Ejections
D'Huys, Elke
In this doctoral thesis we study stealth CMEs: solar coronal mass ejections that are clearly observed in coronagraph data but do not show significant low-coronal or on-disk signatures of eruption. This lack of coronal signatures makes it challenging to determine their source region and predict their trajectory throughout interplanetary space. Comb…
Dense Image Matching for Mars Express HRSC Imagery Based on Precise Point Prediction Method
Geng, X.; Xu, Q.; Xing, S. +3 more
Currently, Mars Express HRSC imagery is an essential data source to derive high accuracy Mars topographic data. In view of the characteristics of Martian surface satellite imagery, a dense image matching scheme for HRSC imagery based on precise point prediction method is proposed. The image matching strategies of our method are elaborated in detai…
El programa científico de la Agencia Espacial Europea
Gabriel, C.
The rendezvous of the spatial mission Rosetta with the comet 67P/Churyumov-Gerasimenko and the spectacular deployment of the Philae lander to its surface marked the conclusion of the European Space Agency's (ESA's) scientific program Horizon 2000, 30 years after it had been conceived, back in 1985. Three of its cornerstone missions continue today …