Search Publications
Electron density distribution and solar plasma correction of radio signals using MGS, MEX, and VEX spacecraft navigation data and its application to planetary ephemerides
Issautier, K.; Laskar, J.; Fienga, A. +3 more
The Mars Global Surveyor (MGS), Mars Express (MEX), and Venus Express (VEX) experienced several superior solar conjunctions. These conjunctions cause severe degradations of radio signals when the line of sight between the Earth and the spacecraft passes near to the solar corona region. The primary objective of this work is to deduce a solar corona…
Comparisons of CME Morphological Characteristics Derived from Five 3D Reconstruction Methods
Mierla, M.; Feng, L.; Inhester, B.
We compare different methods to reconstruct three-dimensional (3D) coronal mass ejection (CME) morphology. The explored methods include geometric localisation, mask fitting, forward modelling, polarisation ratio, and local correlation tracking plus triangulation. These five methods are applied to the same CME event that occurred on 7 August 2010. …
Initial Fe/O Enhancements in Large, Gradual, Solar Energetic Particle Events: Observations from Wind and Ulysses
Marsden, Richard G.; Ko, Yuan-Kuen; Malandraki, Olga E. +4 more
Shocks driven by fast coronal mass ejections (CMEs) are the dominant particle accelerators in large, "gradual" solar energetic particle (SEP) events. In these events, the event-integrated value of the iron-to-oxygen ratio (Fe/O) is typically ∼ 0.1, at least at energies of a few MeV/nucleon. However, at the start of some gradual events, when intens…
Meteorology of Jupiter's equatorial hot spots and plumes from Cassini
Showman, Adam P.; Simon-Miller, Amy A.; Vasavada, Ashwin R. +1 more
We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their inter…
Copious Amounts of Hot and Cold Dust Orbiting the Main Sequence A-type Stars HD 131488 and HD 121191
Zuckerman, B.; Murphy, Simon J.; Song, Inseok +3 more
We report two new dramatically dusty main sequence stars: HD 131488 (A1 V) and HD 121191 (A8 V). HD 131488 is found to have substantial amounts of dust in its terrestrial planet zone (L IR/L bol ≈ 4 × 10-3), cooler dust farther out in its planetary system, and an unusual mid-infrared spectral feature. HD 121191 sho…
Characterizing the Dust Coma of Comet C/2012 S1 (ISON) at 4.15 AU from the Sun
Kolokolova, Ludmilla; Weaver, Harold A.; A'Hearn, Michael F. +7 more
We report results from broadband visible images of comet C/2012 S1 (ISON) obtained with the Hubble Space Telescope Wide Field Camera 3 on 2013 April 10. C/ISON's coma brightness follows a 1/ρ (where ρ is the projected distance from the nucleus) profile out to 5000 km, consistent with a constant speed dust outflow model. The turnaround distance in …
Timing and Interstellar Scattering of 35 Distant Pulsars Discovered in the PALFA Survey
Popa, L.; Camilo, F.; Ransom, S. M. +34 more
We have made extensive observations of 35 distant slow (non-recycled) pulsars discovered in the ongoing Arecibo PALFA pulsar survey. Timing observations of these pulsars over several years at Arecibo Observatory and Jodrell Bank Observatory have yielded high-precision positions and measurements of rotation properties. Despite being a relatively di…
The Location of Non-thermal Velocity in the Early Phases of Large Flares—Revealing Pre-eruption Flux Ropes
Culhane, J. L.; Harra, Louise K.; Hara, Hirohisa +3 more
Non-thermal velocity measurements of the solar atmosphere, particularly from UV and X-ray emission lines have demonstrated over the decades that this parameter is important in understanding the triggering of solar flares. Enhancements have often been observed before intensity enhancements are seen. However, until the launch of Hinode, it has been …
Cosmic Rays Through the Solar Hale Cycle. Insights from Ulysses
Heber, B.
The Ulysses spacecraft had been the first to orbit the Sun over its poles and to explore the heliosphere at these high heliolatitudes. It has now completed three fast latitude scans, two at solar minimum and one at solar maximum. Since its launch in October 1990, this mission has led to several surprising discoveries concerning energetic particles…
Spatial distribution of small hydrocarbons in the neighborhood of the ultra compact HII region Monoceros R2
Le Bourlot, J.; Le Petit, F.; Ossenkopf, V. +14 more
Context. We study the chemistry of small hydrocarbons in the photon-dominated regions (PDRs) associated with the ultra-compact H ii region (UCH ii) Mon R2.
Aims: Our goal is to determine the variations in the abundance of small hydrocarbons in a high-UV irradiated PDR and investigate the chemistry of these species.
Methods: We present an…