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The mesosphere and lower thermosphere of Titan revealed by Cassini/UVIS stellar occultations

Sandel, B. R.; West, R. A.; Yelle, R. V. +5 more

Stellar occultations observed by the Cassini/UVIS instrument provide unique data that probe the mesosphere and lower thermosphere of Titan at altitudes between 400 and 1400 km. This region is a site of complex photochemistry that forms hydrocarbon and nitrile species, and plays a crucial role in the formation of the organic hazes observed in the s…

Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265

Auvergne, M.; Baudin, F.; García, R. A. +27 more

Context. The star HD 52265 is a G0V metal-rich exoplanet-host star observed in the seismology field of the CoRoT space telescope from November 2008 to March 2009. The satellite collected 117 days of high-precision photometric data on this star, showing that it presents solar-like oscillations. HD 52265 was also observed in spect…

Evidence for an FU Orionis-like Outburst from a Classical T Tauri Star

Filippenko, Alexei V.; Cenko, S. Bradley; Law, Nicholas M. +28 more

We present pre- and post-outburst observations of the new FU Orionis-like young stellar object PTF 10qpf (also known as LkHα 188-G4 and HBC 722). Prior to this outburst, LkHα 188-G4 was classified as a classical T Tauri star (CTTS) on the basis of its optical emission-line spectrum superposed on a K8-type photosphere and its photometric variabilit…

Morphological properties of z∼ 0.5 absorption-selected galaxies: the role of galaxy inclination

Kacprzak, Glenn G.; Steidel, Charles C.; Churchill, Christopher W. +2 more

We have used Galaxy IMage 2D (GIM2D) to quantify the morphological properties of 40 intermediate-redshift Mg II absorption-selected galaxies [0.03 ≤ W_r(2796) ≤ 2.9 Å], imaged with WFPC-2/Hubble Space Telescope (HST), and compared them to the halo gas properties measured from HIRES/Keck and UVES/VLT quasar spectra. We find that as the qu…

Organic sedimentary deposits in Titan's dry lakebeds: Probable evaporite

Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +14 more

We report the discovery of organic sedimentary deposits at the bottom of dry lakebeds near Titan's north pole in observations from the Cassini Visual and Infrared Mapping Spectrometer (VIMS). We show evidence that the deposits are evaporitic, making Titan just the third known planetary body with evaporitic processes after Earth and Mars, and is th…

Weak lensing from space: first cosmological constraints from three-point shear statistics

Schrabback, Tim; Hilbert, Stefan; van Waerbeke, Ludovic +3 more

We use weak lensing data from the Hubble Space Telescope COSMOS survey to measure the second- and third-order moments of the cosmic shear field, estimated from about 450 000 galaxies with average redshift ?.

We measure two- and three-point shear statistics using a tree-code, dividing the signal in E, B and mixed components. We present a detec…

Negative X-ray reverberation time delays from MCG-6-30-15 and Mrk 766

Papadakis, I. E.; Emmanoulopoulos, D.; McHardy, I. M.

We present an X-ray time lag analysis, as a function of Fourier frequency, for MCG-6-30-15 and Mrk 766 using long-term XMM-Newton light curves in the 0.5-1.5 and the 2-4 keV energy bands, together with some physical modelling of the corresponding time lag spectra. Both the time lag spectra of MCG-6-30-15 and Mrk 766 show negative values (i.e. soft…

Coronal Field Opens at Lower Height During the Solar Cycles 22 and 23 Minimum Periods: IMF Comparison Suggests the Source Surface Should Be Lowered

Sun, X.; Luhmann, J. G.; Arge, C. N. +3 more

The solar cycle 23 minimum period has been characterized by a weaker solar and interplanetary magnetic field. This provides an ideal time to study how the strength of the photospheric field affects the interplanetary magnetic flux and, in particular, how much the observed interplanetary fields of different cycle minima can be understood simply fro…

Review of Pi2 Models

Keiling, Andreas; Takahashi, Kazue

More than half a century after the discovery of Pi2 pulsations, Pi2 research is still vigorous and evolving. Especially in the last decade, new results have provided supporting evidence for some Pi2 models, challenged earlier interpretations, and led to entirely new models. We have gone beyond the inner magnetosphere and have explored the outer ma…

Planck early results. XXII. The submillimetre properties of a sample of Galactic cold clumps

Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +201 more

We perform a detailed investigation of sources from the Cold Cores Catalogue of Planck Objects (C3PO). Our goal is to probe the reliability of the detections, validate the separation between warm and cold dust emission components, provide the first glimpse at the nature, internal morphology and physical characterictics of the Planck-detected sourc…