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Rapporteur Paper on the Composition of Comets
Altwegg, Kathrin
The ISSI workshop on “Origin and evolution of comet nuclei” had the goal to put together recent scientific findings concerning the “life” of a comet from the formation of the material in a dark molecular cloud to the accretion in the early solar system, from cometesimals to comet nuclei which were shaped and altered by cosmic rays, by radioisotopi…
Young star clusters in the Antennae galaxies and NGC 1487
Lehnert, M. D.; Vacca, W. D.; Chandar, R. +3 more
We estimate the dynamical masses of several young ({≈ 10} Myr) massive star clusters in two interacting galaxies, NGC 4038/4039 (``The Antennae") and NGC 1487, under the assumption of virial equilibrium. These are compared with photometric mass estimates. A dynamical mass substantially higher than the photometric estimate could indicate non-virial…
Global Effects of Local Sound-Speed Perturbations in the Sun: A Theoretical Study
Larson, T. P.; Hanasoge, S. M.
We study the effect of localized sound-speed perturbations on global mode frequencies by applying techniques of global helioseismology to numerical simulations of the solar acoustic wave field. Extending the method of realization-noise subtraction (e.g., Hanasoge, Duvall, and Couvidat, Astrophys. J.664, 1234, 2007) to global modes and exploiting t…
Analysis of the H + ring velocity distribution function near the Martian and Venusian bow shocks by an analytical model
Kallio, E.; Yamauchi, M.; Frilund, H.
We have studied the H + velocity distribution function at Mars and Venus near the bow shock both in the solar wind and in the magnetosheath by a simple analytical one-dimensional model. We found that over half of the ions in the ring velocity distribution which moved towards the magnetosheath were scattered back into the bow shock. The …
Simulating the SMART1 orbiter impact on the Moon's surface
Bratov, V. A.; Morozov, N. F.; Petrov, Yu. V.
Could We Have Forecast "The Day the Solar Wind Died"?
McIntosh, Scott W.; Leamon, Robert J.
In 1999 May an interval of unusually slow (<300 km s-1) and rarefied (<1 cm-3) solar wind was observed upstream of Earth by the ACE spacecraft. The event has been dubbed "The Day the Solar Wind Died." We apply our solar wind forecast model to the interval in question, to ask whether we could have predicted the phenomeno…
The Effect of a Latitudinal Dependent Solar Wind Speed on Cosmic-Ray Modulation in a Fisk-type Heliospheric Magnetic Field
Burger, R. A.; Hitge, M.
The Fisk-model for the heliospheric magnetic field (HMF) was developed in an attempt to connect the structure of the magnetic field at large heliocentric distances to processes in and above the photosphere. A Fisk-Parker hybrid model that is valid for the whole heliosphere (Burger and Hitge 2004, ApJL, 617) and the whole solar cycle (Kruger 2006, …
The Rosetta video approach: An overview and lessons learned so far
Zender, J.; Schwehm, G.; Wilke, M.
After an interplanetary cruise of 10 years, the Rosetta spacecraft and Philae lander, will arrive in 2014 at comet Churyomov-Gerasimenkov. All involved parties are aware of the knowledge decrease during these years and the potential complications that might arise during problem resolution before or during cometary operations. The Rosetta Science O…
Hinode: A New Solar Observatory in Space
Hara, Hirohisa
The third Japanese solar observing satellite, SOLAR-B, was launched on 2006 Sep 23 from the Uchinoura Space Center of JAXA and it was named “Hinode” (sunrise). Hinode carries three major telescopes: Solar Optical Telescope (SOT), X-Ray Telescope (XRT), and Extreme-ultraviolet Imaging Spectrometer (EIS). These telescopes have been built in an inter…
Characteristics of cumulative particle fluences at different heliospheric radii
Király, Péter
Normalized cumulative particle fluence plots are very useful for characterizing the variability of interplanetary suprathermal and energetic particle fluxes on various time scales. For some applications it is practicable to describe the deviations of annual fluence plots from straight lines by a single parameter (the Kolmogorov or K parameter), an…