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A distinct magnetic property of the inner penumbral boundary. Formation of a stable umbra-penumbra boundary in a sunspot
Jurčák, J.; Bello González, N.; Schlichenmaier, R. +1 more
Context. A sunspot emanates from a growing pore or protospot. In order to trigger the formation of a penumbra, large inclinations at the outskirts of the protospot are necessary. The penumbra develops and establishes by colonising both umbral areas and granulation. Evidence for a unique stable boundary value for the vertical component of the magne…
Multiband variability in the blazar 3C 273 with XMM-Newton
Bhagwan, Jai; Gupta, Alok C.; Wiita, Paul J. +2 more
We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM-Newton satellite mission from 2000 June to 2012 July. Here, we focus on the multiwavelength flux variability on both intra-day and long time-scales of this very well known radio-loud source. We…
Formation and Eruption of a Small Flux Rope in the Chromosphere Observed by NST, IRIS, and SDO
Wang, Haimin; Yurchyshyn, Vasyl; Kumar, Pankaj +1 more
Using high-resolution images from the 1.6 m New Solar Telescope at Big Bear Solar Observatory, we report the direct evidence of chromospheric reconnection at the polarity inversion line between two small opposite polarity sunspots. Small jetlike structures (with velocities of ∼20-55 km s-1) were observed at the reconnection site before …
Comet 67P/Churyumov-Gerasimenko: Hardening of the sub-surface layer
Kührt, E.; Spohn, T.; Kaufmann, E. +2 more
From the operation of the MUPUS thermal probe Spohn et al. (2015) concluded that the material of the nucleus of 67P/Churyumov-Gerasimenko is likely to have a high strength, at least locally at the Philae landing site. In this work we consider the derived strength of the material in order to constrain its granulation. For this purpose we performed …
Large-scale cosmic microwave background temperature and polarization cross-spectra likelihoods
Mangilli, A.; Plaszczynski, S.; Tristram, M.
We present a cross-spectra-based approach for the analysis of cosmic microwave background data at large angular scales to constrain the reionization optical depth τ, the tensor to scalar ratio r and the amplitude of the primordial scalar perturbations As. With respect to the pixel-based approach developed so far, using cross-spectra has…
A solar tornado observed by EIS. Plasma diagnostics
Fletcher, L.; Schmieder, B.; Labrosse, N. +1 more
Context. The term "solar tornadoes" has been used to describe apparently rotating magnetic structures above the solar limb, as seen in high resolution images and movies from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). These often form part of the larger magnetic structure of a prominence, however the links b…
WIYN Open Cluster Study. LXVI. Spectroscopic Binary Orbits in the Young Open Cluster M35 (NGC 2168)
Gosnell, N. M.; Leiner, E. M.; Mathieu, R. D. +1 more
The young (150 Myr) open cluster M35 (NGC 2168) has been one of the core clusters of the WIYN Open Cluster Study since 1997. Over these 17 years we have obtained approximately 8000 radial-velocity (RV) measurements of stars in the M35 field, which we provide here. Our target sample consists of 1355 photometrically selected stars in the field of M3…
Binary Frequencies in a Sample of Globular Clusters. II. Sample Analysis and Comparison to Models
Bregman, Joel N.; Ji, Jun
Binary stars are predicted to have an important role in the evolution of globular clusters, so we obtained binary fractions for 35 globular clusters that were imaged in the F606W and F814W with the Advanced Camera for Surveys on the Hubble Space Telescope. When compared to the values of prior efforts, we find significant discrepancies, despite eac…
Recent climate cycles on Mars: Stratigraphic relationships between multiple generations of gullies and the latitude dependent mantle
Goudge, Timothy A.; Head, James W.; Dickson, James L. +1 more
Reconstructions of the orbital parameters of Mars spanning the last ∼20 Myr, combined with global circulation models, predict multiple cycles of accumulation and degradation of an ice-rich mantle in the mid-latitudes, driven primarily by insolation at the poles during periods when obliquity was more than ten degrees greater than it is today (i.e.,…
Internally and externally induced deformations of the magnetospheric equatorial current as inferred from spacecraft data
Gordeev, E. I.; Tsyganenko, N. A.; Andreeva, V. A.
Based on a data pool of 79 yearly files of space magnetometer data by Polar, Cluster, Geotail, and THEMIS satellites between 1995 and 2013, we developed a new quantitative model of the global shape of the magnetospheric equatorial current sheet as a function of the Earth's dipole tilt angle, solar wind ram pressure, and interplanetary magnetic fie…