Chloe Pugh, Valery Nakariakov

Quasi-periodic pulsations (QPPs) are a common feature of solar flares that are observed in many different wavelengths. Although QPPs appear not to be as abundant in white light Kepler flare light curves as they are in solar flares, albeit in different wavelengths the structure of the pulsations are strikingly similar, hinting that the same underlying processes govern both solar and stellar flares. Here we consider a special case, observed on KIC9655129, which shows evidence of multiple periodicities. We speculate that the presence of multiple periodicities is a good indication that the QPPs were caused by magnetohydrodynamic oscillations, further strengthening the case that the physical processes in operation during stellar flares are at least analogous to those in solar flares.

Michael Leguèbe, Damien Fournier, Aaron C. Birch, Laurent Gizon in Collaboration with Inria team Magique3D

We compute acoustic Green’s functions in an axisymmetric solar background model, which may include a meridional flow and differential rotation. The wave equation is solved in the frequency domain using a finite element solver. A transparent boundary condition for the waves is implemented in the chromosphere, which represents a great improvement in computational efficiency compared to implementations based on ’sponge layers’. We perform various convergence studies that demonstrate that wave travel times can be computed with an accuracy of 0.001 s. This high level of numerical accuracy is required to interpret travel times in the deep interior, and is achieved thanks to a refined mesh in the near surface layers and around the source of excitation. The wave solver presented here lays the ground for future iterative inversion methods for flows in the deep solar interior.

One of the outstanding and unforeseen results from the Kepler mission is our new insight and understanding of red giant stars. These highly evolved stars, which are in the last stages of their life, provide extremely useful information when trying to develop stellar evolutionary models. Furthermore, they show stochastically excited oscillations thus allowing to use asteroseismic techniques to derive conditions of the most internal layers. Bright giants stars are well suited to be studied with the 1m telescopes in the Stellar Observations Network Group project (SONG) using a high resolution echelle spectrograph performing high precision measurements of their the radial velocity. The prototype node- the Hertzsprung SONG telescope- was inaugurated in October 2014 and is located at the Teide Observatory on Tenerife and providing continuous and high quality observations since then, When selecting the best targets for SONG, a precision of 1-2 m/s per point is reachable using the iodine method and a number of red giants have been observed with the SONG telescope since scientific operation started. In this talk we present the first results of these specific campaigns for a few red giants in which eigenmodes have been identified and their global seismic parameters derived.

I. Arregui

Damping of transverse waves in different solar coronal structures is a commonly observed property and a source of information about coronal conditions. Although resonant damping seems to be the most accepted mechanism for damping of transverse waves, there are other possible mechanisms. We have carried out a Bayesian analysis comparing three different models which could explain the damping in coronal loops. Our results indicate that resonant absorption is the most probable mechanism for low ratios between damping time and wave period, while the wave leakage mechanism is the best candidate for high ratios. Nonetheless, the evidence for one model against another shows a strong dependence on the data errors.

Gavin Rowell, Matthieu Renaud, Phoebe de Wilt, Fabien Voisin, Yasuo Fukui, Michael Burton, Andrew Walsh, Akiko Kawamura, Andrew Walsh, Akiko Kawamura, Felix Aharonian

We present the results of molecular spectral line observations towards Supernova Remnants such as W28, RX J1713.7-3946 and HESS J1731-347. These remnants exhibit TeV gamma-ray emission, beacons for the presence of enhanced populations of high energy particles. It follows that these objects may accelerate Galactic cosmic-ray protons via the diffusive shock mechanism, but knowledge of the environment local to such remnants is required to constrain such scenarios. The Mopra radio telescope is ideal for probing the interstellar environments of HESS gamma-ray sources through large-scale molecular line surveys. Mopra can be employed to hunt for dense gas-tracing CS and NH3 transitions to identify potential cosmic-ray target material, while simultaneously searching for shock-tracing SiO emission lines which can directly highlight shock-disrupted gas. Furthermore, spectral line width gives an insight into gas dynamics and Mopra is capable of measuring this at a ~1' resolution over degree-scale regions. We present results from recent 7 and 12mm surveys towards the above-mentioned TeV-emitting Supernova Remnants and discuss the implications for distance, the diffusion of cosmic-rays and the high energy gamma-ray spectrum.

Kai Finster, Meilee Ling, Maher Sahyoun, Morten Dreyer, Stine Holm, Martin Rasmussen, Stephanie Pilgaard

The presentation deals with activity of airborne microbial cells and how this is important for expanding our understanding of habitability and biosignatures.

G. Hornig, M.H. Page

What if there were a way to identify **where** the magnetic helicity is concentrated within a three- dimensional magnetic field? At first sight this question appears meaningless, since magnetic helicity is an integral over the whole volume of the magnetic field. But, in fact, it is possible to decompose this total helicity as an integral over individual "field line helicities" for each magnetic field line in the domain. All of these are ideal-invariant, topological quantities, and they allow us to quantify in a meaningful way how magnetic helicity is distributed within the domain. In this talk, I will show how this idea can be practically applied to typical extrapolations of the Sun's coronal magnetic field that are used in solar physics.

The solar electromagnetic and corpuscular emissions are strongly modulated by the evolution of the magnetic structure of the solar atmosphere, which is imprinted in the solar surface. The evolution of the magnetic structure leads to gradual changes in the solar activity (space climate) as well as violent events (space weather) that affect the whole Heliosphere. In particular, the solar output affects the ionized and neutral components of the Earth’s atmosphere that have a direct impact on human activities from agriculture to high-technological systems. The solar magnetism is driven by the energy transport from the inner layers to the solar atmosphere. Although systematic observations have revealed several features related to the evolution of solar activity, there is not a complete explanation of the physical processes that lead to solar activity cyclic variability and its long-term changes. Here we present a brief description of the development of a magnetograph and visible-light imager instrument to study the solar dynamo processes through observations of the solar surface magnetic field distribution. The instrument will provide measurements of the vector magnetic field and the line-of-sight velocity in the solar photosphere. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the Heliosphere, the development of this instrument plays an essential role in reaching the scientific goals of The Atmospheric and Space Science Coordination (CEA) at the Brazilian National Institute for Space Research (INPE). In particular, the INPE’s Space Weather program will benefit most from the development of this technology. Additionally, we expect that this project will be the starting point to establish a robust research program on Solar System Research at INPE. The proposed instrument has been designed to operate on the ground, but with a conceptual design flexible enough to be adapted to work on a balloon and space-based platforms. In this way, our main aim is acquiring know-how progressively to build state-of-art solar vector magnetograph and visible-light imagers for space-based platforms to contribute to the efforts of the solar-terrestrial physics community to address the main unanswered questions on how our nearby Star works.

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Community paper as part of the Denkschrift 2017 - Perspektiven der Astrophysik in Deutschland 2017 - 2030

Von seiner Orientreise 1899/1900 brachte Karl May eine Reihe von Gegenständen und Souvenirs mit. Diese verschenkte er entweder an Freunde und Bekannte oder er fügte damit der Ausstattung seiner Villa exotische Einrichtungsgegenstände hinzu. Zu seinen Mitbringseln gehören auch ein paar ägyptische Antiken, die in diesem Beitrag vorgestellt werden. Die Amulette in Form von Schutzgottheiten sowie ein Uschebti sind aus so genannter ägyptischer Fayence gefertigt. Der Skarabäus ist aus Speckstein (Steatit) geschnitten, die Figuren des Totengottes Osiris sind aus Bronze gegossen. Sie alle sind typische und in der altägyptischen Kultur häufige und beliebte Objekte gewesen.

Die im Sommer 1908 entstandene Novelle 'Merhameh' ist aufgrund ihrer konsequenten Komposition, der knappen und doch bildhaften Sprache sowie der fugenlosen Verschränkung mehrerer Leseebenen die letzte und wohl künstlerisch bedeutende kurze Erzählung Karl Mays. Die Modernität dieser konsequent pazifistischen Erzählung, in deren Handlung die früheren Helden Kara Ben Nemsi und Hadschi Halef Omar nur noch Statisten sind, besteht darin, dass May hier bis ins Detail Wirkungsmechanismen der gewaltfreien Interaktion literarisch gestaltet, die im 21. Jahrhundert zum Gegenstand sozialwissenschaftlicher Untersuchungen wurden. So gibt es weitgehende Übereinstimmungen zwischen Mays Darstellung der schrittweisen und gewaltfreien Konfliktlösung und dem - ausgehend von praktisch wirkungsvollen Modellen aktiver Gewaltfreiheit (Gross-Mayr, Gandhi, de Ligt) entwickelten - 'Gütekraft'-Wirkungsmodell des Friedensforschers Martin Arnold, das 2011 publiziert wurde.

Here you can download the EST Brochure.

In this paper, the inclined side weir discharge coefficient was studied using a side weir with three different crest angles (θ = 4°, 8°, 12°) fixed either against and in the flow direction, and the results are compared with those from a horizontal side weir crest (θ = 0°). In total there were seven models. The results show that the De Marchi assumption of constant energy for all side weir crested angles is acceptable, and thus that the calculated weir discharge value can therefore be undertaken. An equation for the discharge coefficient was obtained for an inclined side weir, so the value of Cd for crest angle θ = 12° increased by 13.6% with respect to the value for θ = 8°, by 29% with respect to that for θ = 4°, and by 39% with respect to that for the horizontal case (θ = 0°), for a crest inclined against the flow direction, while when the crest was inclined in the flow direction all those values exceed, to 14.5%, 31.0%, and 40.7%, respectively. This means that the discharge increases with increasing side weir crest angle, so when we want uniformity in the flow direction and exceed discharge we need to make the side weir crest incline against the flow direction while when we want furthermore discharge we need to make the side weir crest incline in the flow direction.

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Dessy Rutten, Tim Ganzeman, Bart Schellekens, Wessel Hijman, Jorg van der Burgt, Luuk van der Geest, Hidde Ceelen, Colin Tan, Khetab Mashhadi, Femke Janssen, Sam Niesten, Koen van Rixtel, Rick Bos, Amber Meijering

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Freiburg, Germany

Bairisch-Kölldorf, Austria

Tokyo (Japan)