Search Publications
ESA multibody simulator for spacecrafts' ascent and landing in a microgravity environment
Toso, Mario; Pennestrì, Ettore; Rossi, Valerio
The investigation of planets, moons and small bodies, including comets and asteroids can contribute substantially to our understanding of the formation and history of the solar system. In situ observations by landers play an important role in this field: for example, the Rosetta Lander Philae has been the first spacecraft to accomplish a soft touc…
Global frequency distributions of pulsations driven by sharp decrease of solar wind dynamic pressure
Wang, Zhi Qiang
On 24 August 2005, an impulse of solar wind dynamic pressure (Psw) hit the magnetosphere. Using the high resolution geomagnetic field data from 15 ground stations and the data from Geotail and TC-1, we studied the geomagnetic pulsations at auroral latitudes driven by the sharp decrease of Psw at the trailing edge of the impulse. The results show t…
Ultraviolet spectral behavior of AO Psc and V1223 Sgr from the HST and IUE satellites
Sanad, M. R.
We present a spectroscopic study of two intermediate polar systems, AO Psc and V1223 Sgr observed with the Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) and International Ultraviolet Explorer (IUE) during the period 1980–2000. The reddening of two systems is determined from the 2200 Å feature. The ultraviolet emission line…
Powerful non-geoeffective interplanetary disturbance of July 2012 observed by muon hodoscope URAGAN
Veselovsky, I. S.; Astapov, I. I.; Barbashina, N. S. +2 more
The most powerful coronal mass ejection of the 24th solar cycle took place on the opposite side of the Sun on July 23, 2012 and had no geomagnetic consequences. Nevertheless, as a result of passing of the ejection through the heliosphere, variations of galactic cosmic rays flux were observed on the Earth. These variations were registered by the mu…
A Warp in Progress: H I and Radio Continuum Observations of the Spiral NGC 3145
Brinks, Elias; Struck, Curtis; Elmegreen, Bruce G. +2 more
VLA H i observations and λ6 cm radio continuum observations are presented of the barred-spiral galaxy NGC 3145. In optical images NGC 3145 has stellar arms that appear to cross, forming “X”-features. Our radio continuum observations rule out shock fronts at three of the four “X”-features, and our H i data provide evidence of gas motions perpendicu…
Planetary host stars: evaluating uncertainties in cool model atmospheres
Scholz, A.; Helling, Ch.; Bozhinova, I.
M-dwarfs are emerging in the literature as promising targets for detecting low-mass, Earth-like planets. An important step in this process is to determine the stellar parameters of the M-dwarf host star as accurately as possible. Different well-tested stellar model atmosphere simulations from different groups are widely applied to undertake this t…
Angular momentum and Philae's descent
Blanco, Philip
On the Hipparcos Accuracy Using Binary Stars as a Calibration Tool
Docobo, J. A.; Andrade, M.
Stellar binary systems, specifically those that present the most accurate available orbital elements, are a reliable tool to test the accuracy of astrometric observations. We selected all 35 binaries with these characteristics. Our objective is to provide standard uncertainties for the positions and parallaxes measured by Hipparcos relative to thi…
The February 24, 2010 substorm: a refined view involving a pseudobreakup/expansive phase/poleward boundary intensification sequence
Russell, Christopher T.; McPherron, Robert L.; Chu, Xiangning +1 more
A substorm on February 24, 2010 was chosen for study by Connors et al. (Geophys. Res. Lett. 41:4449–4455, 2014) due to simple symmetric subauroral magnetic perturbations observed in North America. It was shown that a substorm current wedge (SCW) three-dimensional current model could represent these perturbations well, gave a reasonable representat…
The discrepancy in the mid-infrared continuum and the features of polycyclic aromatic hydrocarbons for Spitzer and Herschel SWIRE-field galaxies
Wu, Hong; Zhu, Yi-Nan
On the basis of observations by Spitzer and Herschel, we present and analyse the correlations between various monochromatic infrared (IR) luminosities for star-forming galaxies, selected from two northern Spitzer Wide-area InfraRed Extragalactic Survey (SWIRE) fields. The 24- and 70-µm luminosities (L[24] and L[70]), which are dominated by t…