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Great White Spots on Saturn: current and historical observations

McKim, R. J.

The bright spot in Saturn's North Tropical Zone which developed in 2010 December prompted the writer to collect together some rare and unpublished observations of previous Great White Spots (GWS) on the planet. As illustrated by series of observations in 1876, 1933 and 1990, and for 1903 and 1960, these GWS show a tendency to recur at intervals of…

Enceladus Now Looks Wet, So It May Be ALIVE!

Kerr, Richard A.

Observational Evidence for Grain Growth

Meeus, Gwendolyn

Discs around young stars are the sites of planet formation. The first step in this process is the growth of submicron grains to larger sized grains. I will review evidence for dust growth in CS discs, based on ISO and Spitzer infrared spectroscopic observations. Intermediate-mass stars, solar-type stars and even brown dwarfs will be discussed in t…

X-ray spectral evolution of TeV BL Lacertae objects: eleven years of observations with BeppoSAX, XMM-Newton and Swift satellites (Corrigendum)

Tramacere, A.; Giommi, P.; Perri, M. +2 more

The peculiar O9.5V star BD+53°2790, the massive counterpart to the X-ray binary system 4U 2206+54

Blay, Pere; Reglero, Víctor

The X-ray binary system 4U 2206+54 hides many mysteries. Among them, the surprising behavior of both of its co components: the O9.5 dwarf star BD+53°2790 and a slowly rotating neutron star. BD+53°2790 misled the astronomers, exhibiting characteristics reminiscent of Be stars. However, a deeper spectral analysis and more intense monitoring revealed…

Reduced magnetic helicity behavior in different plasma regions of near-Earth space

Perri, S.; Carbone, V.; Yordanova, E.

We present a comparative study of the scaling laws of a signed measure calculated from the reduced magnetic helicity from Cluster observations in three different near-Earth plasma regions: solar wind, foreshock, and magnetosheath. The reduced magnetic helicity provides information about the handedness of the magnetic field, which can be related to…

Wave absorption and moat flow in AR9787

Thompson, M. J.; Roth, M.

We present the results of a study of the wave absorption and the moat flow around the sunspot in AR9787 (the "HELAS sunspot", so-called because it has been the object of in-depth study at a HELAS workshop) using Fourier-Hankel decomposition of the oscillatory wave field. We carry out inversions both for the flow speed and for the sound speed pertu…

Temporal Relation Between the Disappearance of Penumbral Fine-scale Structure and Evershed Flow

Kubo, M.; Lites, B. W.; Ichimoto, K. +1 more

We investigate the temporal relation between the Evershed flow, dot-like bright features (penumbral grain), the complex magnetic field structure, and dark lanes (dark core) along bright filaments in a sunspot penumbra. We use a time series of high spatial resolution photospheric intensity, vector magnetic field maps, and Doppler velocity maps obta…

Quantifying energy transfer at the magnetopause

Dandouras, I.; Lucek, E. A.; Palmroth, M. +4 more

X-Ray and Gamma-Ray Emission of the Shell-Type Supernova Remnant RX J1713.7-3946

Zhang, Li; Yang, C. Y.

To study possible origins of high-energy gamma-ray emission from shell-type supernova remnants, RX J1713.7-3946, we model their nonthermal photon spectra from X-ray to very high energy (VHE) gamma-ray bands in the frame of non-linear diffusive shock acceleration, respectively. In our modeling, the accelerated proton spectrum is calculated based on…