Discussions on Comets - Heat transport phenomena in the outer layers of cometary nuclei [mehr]

MPS Seminar: Reflecting MHD waves in hot coronal loops observed by SDO/AIA (P. Kumar)

  • Datum: 25.07.2014
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Pankaj Kumar
  • Korea Astrononomy and Space Science Institute (KASI), Deajeon, Korea
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Hardi Peter
Reflecting MHD waves in hot coronal loops observed by SDO/AIA [mehr]

Planetary Group Seminar: "The search for life on Mars, a search on two planets" (A. Steele)

"The search for life on Mars, a search on two planets" Abstract: The search for life on Mars is a journey involving high resolution analysis of meteorites on earth and highly capable robotic packages sent to the surface of Mars. The lecture will review how these two approaches are revealing new insights into the search for life elsewhere and the origin of life on earth. [mehr]

Planetary Group Seminar: The Flybys of Comets Tempel 1 and Hartley 2 (J. Sunshine)

The Flybys of Comets Tempel 1 and Hartley 2 Abstract: The flybys of comets T1 and H2, while short-lived, provide new insights and questions about cometary formation and evolution. The major results from the imager and IR spectrometer will be discussed, with particular emphasis on compositional inferences. [mehr]

Rosetta Seminar: 67P Dust environment from GIADA and OSIRIS data (M. Fulle)

67P Dust environment from GIADA and OSIRIS data Abstract: GIADA is continuously collecting dust since 11 August 2014. Although designed to work at comet distances much closer than those actually planned, thanks to dust loss rates higher than predicted, GIADA is measuring the impact momentum of about a dust grain per day. For the biggest samples, the grain cross section, bulk density and velocity vector has been also determined. These observations have been complemented by 48 OSIRIS single grain detections performed on 4 August 2014, allowing us to complete the dust size distribution up to the largest ejected sizes (actually, some cm). I will discuss results, dust-to-gas ratio and cross section distribution, with comparisons of predictions by the GIADA dust model (2010). [mehr]

MPS Seminar: Asteroseismology, Exoplanets, and Galactic Archaeology: intriguing matches along the (Milky) way (V. Silva)

Asteroseismology, Exoplanets, and Galactic Archaeology: intriguing matches along the (Milky) way [mehr]

Discussion on Comets: Bound grains orbiting 67P: are we sure of that ? (M. Fulle)

Bound grains orbiting 67P: are we sure of that ? [mehr]

MPS Seminar: Magnetic fields of stars and their influence on the habitability of Exoplanets (T. Lüftinger)

Magnetic fields of stars and their influence on the habitability of Exoplanets [mehr]

Discussions on Comets: A Meteorite Science View of Comets and the Rosetta Mission (M. Izawa)

A Meteorite Science View of Comets and the Rosetta Mission [mehr]

MPS Seminar: Evolution of the Solar Luminosity During Solar Cycle 23 (L. Vieira)

Evolution of the Solar Luminosity During Solar Cycle 23 [mehr]

MPS Seminar: The Constant Sun: Measuring the Solar Radius and Oblateness with the Helioseismic and Magnetic Imager (R. Bush)

MPS Seminar: High resolution spectropolarimetric study of sunspot light bridges (L. Bharti)

High resolution spectropolarimetric study of sunspot light bridges [mehr]

MPS Seminar: Fast magnetic reconnection in the solar chromosphere mediated by the plasmoid instability (L. Ni)

  • Datum: 23.10.2014
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Lei Ni
  • Yunnan Observatories, Kunming, China and University Potsdam, Germany
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Hardi Peter
Fast magnetic reconnection in the solar chromosphere mediated by the plasmoid instability [mehr]
The solar butterfly diagram: from a low-dimensional model to new proxies of solar activity [mehr]
Separable solutions of force-free spheres and applications to solar active regions [mehr]

Planetary Group Seminar: Using oxygen isotopes in planetary sciences (A. Pack)

Using oxygen isotopes in planetary sciences [mehr]

Planetary Group Seminar: Titan’s chaotic upper atmosphere (I. Mueller-Wodarg)

Titan’s chaotic upper atmosphere Abstract: Saturn’s largest moon Titan has been observed systematically since the arrival of Cassini/Huygens in 2004. While the landing of the Huygens probe in January 2005 provided amongst other a continuous, yet single vertical profile of atmospheric properties from the thermosphere down to the surface, regular in-situ observations by the Cassini orbiter’s Ion Neutral Mass Spectrometer (INMS) above 950 km provided information on global and time variations in Titan’s thermosphere. Infrared remote sensing onboard Cassini provided further details on Titan’s stratosphere and troposphere, while UV occultations measured the mesosphere and lower thermosphere.   After 10 years of regular observations, Titan has proven to possess one of the most enigmatic atmospheres explored to-date. Density variations observed in the thermosphere show dramatic variations by orders of magnitude between observations and temperatures can vary by 100 K from one flyby to another - rates which are difficult to interpret physically. Equally, horizontal structures are counter-intuitive, suggesting a slightly hotter dayside than nightside on Titan. Work over the past years has attempted and largely failed to systematically correlate these atmosphere structures with changing conditions in Saturn’s magnetosphere, another potential energy source.  Most recently, our work has explored the potential influence of vertical coupling in the atmosphere, of Titan’s lower atmosphere driving changes above. By coupling the Titan WRF stratosphere model with our Titan Thermosphere General Circulation Model, we have found small and short term variations in the stratosphere to drive considerable variability in the thermosphere as well, remarkably consistent with observations. Our findings highlight the broader principle of processes which play a secondary role in atmospheres of bodies closer to the Sun becoming primary in nature in atmospheres further out in the solar system where solar heating is no longer a dominant thermal energy source. [mehr]

MPS Seminar: Fragmented currents induced by shear flows as heating and dissipation mechanisms in flares and the quiet solar atmosphere (D. Nickeler)

Fragmented currents induced by shear flows as heating and dissipation mechanisms in flares and the quiet solar atmosphere [mehr]

Video-Seminar: Magnetic Islands and Singular Currents at Rational Surfaces in Three-dimensional MHD Equilibria (J. Loizum)

Magnetic Islands and Singular Currents at Rational Surfaces in Three-dimensional MHD Equilibria [mehr]

MPS Seminar: SOFIA - past, present, and future (H. Zinnecker)

SOFIA - past, present, and future Abstract:SOFIA, the Stratospheric Observatory for Infrared Astronomy, has reached full operational capability in April 2014 and has since undergone a major overhaul at Lufthansa Technik in Hamburg. Cycle 3 observing time has been awarded and some 80 flights will be carried out in 2015, including a southern deployment to New Zealand. In this talk we will summarize the current status of SOFIA, its instrument suite, and some of the recent science highlights of Cycle 1 and 2 (e.g. star formation and astrochemistry). After a difficult year in terms of NASA support, SOFIA is getting back into gear poised to continue delivering unique mid- and far-infrared science, in the post-Spitzer and post-Herschel era. [mehr]

MPS Seminar: Primary cause of the extended cycle 23 minimum (J. Jiang)

Primary cause of the extended cycle 23 minimum [mehr]

MPS Seminar: Spectropolarimetry for solar magnetometry (R. Manso Sainz)

Spectropolarimetry for solar magnetometry [mehr]

Planetary Group Seminar: Rocks from Vestas: Implications for understanding Earth’s evolution (K. Mengel)

  • Cancelled!
  • Datum: 06.05.2015
  • Uhrzeit: 10:00 - 11:00
  • Vortragende(r): Kurt Mengel
  • University of Technology, Clausthal, Germany www.ielf.tu-clausthal.de
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall

S3 Seminar: Correlation of Magnetic Field wiht Chromospheric Features (K. Barczynski)

MPS Seminar: A Closer Look at Sunspot Oscillations with IRIS (C. Madsen)

  • Datum: 07.05.2015
  • Uhrzeit: 14:30 - 15:30
  • Vortragende(r): Chad Madsen
  • Harvard-Smithsonian Center for Astrophysics, Cambridge and Boston University
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Hardi Peter

Solar Group Seminar: How deep are sunspots? (B. Beeck)

MPS Seminar: Spring in Martian polar areas (G. Portyankina)

Spring on Mars is a time of active changes in polar areas, at latitudes covered by seasonal CO2 ice. The High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter (MRO) has imaged five southern and four northern spring seasons. This temporal coverage allows studying seasonal changes in details, comparing phenomena in the south to the north, and one spring to the next. The volatile nature of the CO2 sublimation in spring leads to erosion and local redistribution of loose material on the surface. The best known and one of the most enigmatic examples of resulting terrain are so called araneiforms (shown in Fig. 1). Araneiforms are observed in southern polar areas only. They are believed to be troughs carved in the substrate by gaseous CO2, with the CO2 ice layer subliming from its bottom. In the northern hemisphere seasonal activity is mostly concentrated on the circumpolar dunes. When gaseous CO2 travels between seasonal ice layer and the dune surface, it creates furrows – channels so small, they get erased in summer by sand movement and created again in spring. The dark and bright fans, observed in both north and south polar areas (an example from the north is in Fig. 2) are a representation of the same phenomena. The fans are results of outbursts of CO2 gas coming from below CO2 ice layer dragging dust and sand with it. A hypothesis for creating the observed phenomena was proposed by H. Kieffer. It is based on the solid-state green house effect acting in the seasonal CO2 ice layer. The diversity of observed features in seasonal polar caps of Mars are produced when this process interacts with water ice, dust, and/or sand grains of the surface and the atmosphere. Most recent observations as well as modeling of spring activity on Mars and related experimental investigations will be discussed in the talk. [mehr]

S3 Seminar: Fast Solar Polarimeter: First Results and Future Work (F. Iglesias)

Planetary Group Seminar: At the heart of Jupiter's aurora (D. Grodent)

  • Datum: 21.05.2015
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Denis Grodent
  • Laboratory for Planetary and Atmospheric Physics Université de Liège, Belgium
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall

MPS Seminar: Short-period free oscillations of the atmosphere (S. Ermolenko)

Planetary Group Seminar: Waves in terrestrial and planetary atmospheres (E. Yigit)

Atmospheric gravity waves are basic features of all planetary atmospheres. But what is their importance? In Earth's atmosphere they are primarily generated by various meteorological processes, propagate upward, produce substantial dynamical and thermal effects and variability in the mesosphere and thermosphere, and thus vertically couple the lower and upper atmosphere. Similar gravity wave processes are increasingly encountered in other planetary atmospheres. In this seminar, I will introduce how small-scale gravity waves are represented in global models and present a snapshot of recent progress in modeling their effects, specifically, in Earth and Martian atmospheres. Gravity wave processes in the context of NASA’s MAVEN mission are discussed. [mehr]
I will present first results obtained from a combined dataset of 700 red giant stars in two fields of the Galactic disc which have been co-observed by the CoRoT satellite and the APOGEE spectrograph. We have measured chemical abundance patterns and ages of field stars over a large radial range of the Milky Way's disc, and present recent results on the dependence of abundance distributions on age and position in the disc. A particularly intriguing result is that the tight correlation between age and chemical abundances previously seen in the Solar vicinity does not seem to be valid for the inner Galactic disc: [alpha/Fe]-rich stars are not necessarily old. [mehr]

S3 Seminar: The Activity of Comet 67P / CG (S. Höfner)

S3 Seminar: Formation of Comets by Gravitational Collapse of Pebble Clouds (S. Lorek)

Planetary Group Seminar: AIDA: Asteroid Impact & Deflection Assessment (J.-B. Vincent)

The AIDA mission will be the first space experiment to demonstrate asteroid impact hazard mitigation by using a kinetic impactor to deflect an asteroid. It consists of ESA's orbiter AIM which will orbit the binary asteroid Didymos in 2022, and NASA's DART projectile scheduled for impact on the secondary in October 2022, while Didymos is at its closest approach to Earth. Both AIM and ground based telescopes will measure the change of orbit of the secondary. AIDA will return vital data to determine the momentum transfer efficiency of the kinetic impact and measure key physical properties of the target asteroid. Additionally, a lander and a full suite of instruments will give us the first tomographic map of an asteroid interior. [mehr]

Planetary Group Seminar: A tale about dwarfs (M. Hoffmann)

The Dawn spacecraft has visited asteroid Vesta and is now in orbit around dwarf planet Ceres. Its data revealed quite individual bodies despite similar size and similar location in the solar system. These “minor planets” are new milestones on the way to a revised view onto the planets: Classification as “planets”, “comets”, “satellites” becomes more misleading than describing. A comparative view on the former “asteroids” Vesta and Ceres will demonstrate this. [mehr]

S3 Seminar: Coronal Active Region Modelling based on SDO Data (S. Barra)

Solar Group Seminar:Polarisation in Astrophysics (S.K. Solanki)

S3 Seminar: Heliseismologiy of Subsurface Flows (Z. Ferret)

S3 Seminar: Linear Simulations of Acoustic Waves in Spotted Stars (E. Papini)

S3 Seminar: Observing and Modelling the Dust Mantle Activity on Comet 67P / C.-G. (X. Hu)

S3 Seminar: Photometric Calibration of Historical SHGs (T. Chatzistergos)

S3 Seminar: Anomalous Reversed Evershed Flow in a Sunspot Penumbra (A. Siu)

MPS Seminar: THOR: Turbulent Heating ObserveR (E. Kronberg)

Rosetta Seminar: Sunset Jets (X. Shi)

MPS Seminar: Understanding comets with Rosetta (M. A'Hearn)

Planetary Group Seminar: The Heavy Bombardment Eon of the Earth-Moon-System (V. Assis Fernandes)

  • Datum: 03.09.2015
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Vera Assis Fernandes
  • Museum für Naturkunde, BerlinLeibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin The Centre for Earth Evolution and Dynamics, University of Oslo, Oslo
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall
Introduction: The impact cratering shaped Moon’s landscapes offer a fossil record of the Near Earth Object populations. This record goes back to the formation and cooling of the lunar crust [1-3] when the crust was sufficiently viscous to retain the cratering “scars”. The crater densities of highland and mare surfaces testify a substantially higher impact flux rate during the first ~1.5 Ga compared to that for the last 3 Ga of our Solar System. The temporal evolution of the impact flux (i.e., the bombardment timeline) is the topic of intense scientific debate for at least the past 40 years. The end-member interpretations are 1) the “Early Heavy Bombardment” (EHB) that assumes an exponentially declining impact flux rate until it oscillated around a much lower value during the last 3 Ga, and 2) the “Late Heavy Bombardment” (LHB) referring to a brief “terminal lunar cataclysm” with a sharply rising and falling peak centered around 3.9 Ga ago [1,2]. On current state of concepts: While the EHB may still be considered the least assumptions model consistent with our fuzzy sample-based knowledge of the bombardment timeline, it lacks a proper physical (orbital) explanation. In light of the recent knowledge from lunar, terrestrial and asteroid belt samples, the classical LHB scenario is no longer attractive [1,2]. In addition, it appears highly inconsistent with orbital models [4-5]. This particularly stems from the difficulty or even impossibility to properly correlate the Apollo and Luna samples to their bedrock or crater ejecta source. However, present re-interpretation of old data together with acquisition of new data from Apollo and Luna samples suggest that intermediate views that consider a complex bombardment timeline with moments of heavy bombardment are a better venue to consensus. Two events able to initiate moments of heavy bombardment are: 1) The giant Moon forming impact event created an extremely massive heliocentric debris disk; meaning a new projectile population with high impact probability onto the Earth and the Moon for the following few hundred million years [6-7]. 2) The reorganization of the planetary system architecture as proposed by the updated “Nice”-model basically explains the extended tail-end of the heavy bombardment as testified by the crater density on mare basalts and possibly the Archean spherule layers on Earth [4]. However the level of resolution in dynamical models is not yet equal to data from samples. 3) Other impactor populations (planetary left overs, comets, debris discs, asteroid belts) that resulted from single events or dynamical processes leading to additional spikes in the impact flux cannot be excluded. One should be aware that “you don’t know what you don’t know”. Therefore, additional work on current samples and/or new samples is required. Acknowledgments: All this work has been carried out in collaboration with Jörg Fritz and Stephanie Werner. References: [1] Fernandes V. A. et al. 2013. MaPS 48:241–269. [2] Fritz J. et al. 2014. PSS 98:254–267. [3] Werner S.C. et al. 2002. Icarus 156:287-290. [4] Werner, S.C. 2014. EPSL 400:54–65. [5] Morbidelli A. et al. 2012. EPSL 355:144–151. [6] Schlichting H. et al. 2012. Astroph. J. 8:8. [7] Jackson A.P. and Wyatt M. 2012. Month. N. R. Astron. Soc. 425:657–679. [mehr]

MPS Seminar: Probing Solar Magnetic Fields at the Base of Convection Zone (D. Chou)

Rosetta Seminar: First touch down of Philae - an update (R. Roll)

MPS Seminar: Numerical simulation modelling of convection and pulsation (F. Kupka)

Solar Group Seminar: Eruptions at Sun and in the Laboratory (J. Büchner)

MPS Seminar: Asteroseismology: Observations of solar-like pulsators (G.Davies)

Göttinger Literaturherbst: Auf der Suche nach den ältesten Sternen (A. Frebel)

Anna Frebel ist der Shootingstar unter den Astrophysikern. Als sie Mitte zwanzig war, mitten in ihrer Promotion, entdeckte sie den bis dato ältesten bekannten Stern. Dass das nicht nur einem Zufall geschuldet war, beweist ihr zweiter Fund kurz darauf: ein noch älterer Stern, etwa 13 Milliarden Jahre alt. Inzwischen ist die „Archäologin der Sterne“ Physikprofessorin am renommierten MIT in Massachusetts. In Göttingen stellt Anna Frebel ihre Arbeit vor, die sie in dem Buch Auf der Suche nach den ältesten Sternen (S. Fischer 2012) anschaulich erklärt. Im Gespräch mit Prof. Sami K. Solanki (Max-Planck-Institut für Sonnensystemforschung) gibt die Wissenschaftlerin einen Einblick in die Entstehung des Universums, der ersten Sterne und berichtet über ihre Arbeit als stellare Archäologin. [mehr]
Assumptions on the early evolution of the Asteroid Vesta include a combined (i) ordinary plus carbonaceous chondritic bulk composition, (ii) complete melting of the silicate fraction within tens of Ma after CAI, (iii) equilibration of silicate material and FeNiS-core, as well as (iv) formation of an ultramafic (peridotitic/pyroxenetic) lower crust and upper mantle plus a basaltic crust. There is, however, little consensus about the volume proportions within the silicate components. Estimates of the thickness of the basaltic crust depend on crystallization models of the bulk silicate composition. The diogenitic component of DAG 779 (believed to originate from Vesta) reveals temperatures of orthopyroxene (opx) formation from 1450 and 1200 °C measured for bulk exsolved opx and for host regions between exolution lamellae , respectively. This range coincides with calculated temperatures of opx formation by equilibrium and fractional crystallization sequences for Vestas silicate shell. Calculations of the thickness of the remaining basaltic (eucritic) crust and the onset of the ultramafic interior suggest depths of 20 to 40 km. The early large impacts that produced the Veneneia and Reasilvia basins most probably excavated rocks from this depth but did not produce large amounts of olivine-rich rocks on Vestas surface. In the light of the above mentioned crystallization models, an orthopyroxenite-rich layer can be assumed to depth of up to 80 km; olivine-dominated rocks are probably restricted to Vestas deeper mantle. [mehr]

Kometenfieber: Kometenforschung von Giotto bis Rosetta (E. Grün)

Öffentliche Vortragsreihe

MPS Seminar: Seismic investigations of the Lithosphere (J.L. Dimech, New Zealand)

Planetary Group Seminar: Deep subsurface radio probing of the icy moons: what can we expect from it? (Y. Ilyushin)

Icy moons of giant planets are now known to have liquid water oceans beneath their icy mantles. Deep radio probing is the only chance to get immediate proof of that now. In the presented talk, issues of deep radio probing of icy moons are addressed. Previously developed theoretical background of Martian GPR exploration is reviewed. A new type instrument concept -- a passive radio wave sounder -- is introduced. Utilization of Jovian natural radio emissions as a sounding wave allows to create a low mass and weight radio instrument exceeding active radars in sounding capabilities. Comparative analysis of both active and passive instrument types and simulation results supporting feasibility of the new instrument are presented. [mehr]
Recent surface processes on Mars are dominated by aeolian and ice-related activity controlled by seasonal atmospheric cycles. For the Martian past, it has become widely accepted that cyclic changes in the planet's orbital configuration has been causing changes on much larger temporal and regional scales leading to re-distribution of polar ices and deposition of ice-rich so-called mantling deposits. While some observational evidence indeed points towards links between extensive mid-latitude glaciation and climate cycles on Mars, questions related to the origin of ice remain unanswered. In this talk, some of these links based on geomorphic observations are discussed. [mehr]

MPS Seminar: Observing Cycles, Seasons, and Storms (S.W. McIntosh)

Recent observational findings suggest that the 11(-ish) solar sunspot cycle is a pattern resulting from the interaction, or interference, of large scale magnetic field bands that evolve within the Sun’s convective interior over it’s 22-year magnetic polarity reversal cycle. These toroidal magnetic bands are anchored deep in the solar convection zone and migrate from high latitudes to the equator over 22 years, and new analysis techniques have allowed us to trace their migration from birth to death. We will see that the spatio-temporal interaction of these magnetic bands helps us frame the landmarks of the sunspot cycle with a surprising realization that, once considered, permits a deeper look into the gross energetics of the star, its radiative, particulate and eruptive output and how they vary with time. It is possible that, with refinement and an ongoing commitment to synoptic observational programs, these results offer greatly improved forecast skill on monthly, annual and decadal timescales while a comprehensive physical model can be developed. Finally, we'll think about what observations are required to "close the loop" and drive that modeling effort. [mehr]

Planetary Group Seminar: Are HED meteorites from asteroid (4) Vesta? (G. Thangjam)

Meteorites are often used as ground truth for celestial bodies for which we have no samples. For the Moon the link between lunar samples and their origin has been proven. Among the achondrites, HED meteorites are one of the most abundant population. The hypothesis that HED meteorites have originated from Vesta has generally been accepted. However, recently this assumption has been questioned in the literature. Because of the relevance of this hypothesis for the analysis of remote sensed data from Vesta, we review the pros and cons of the ongoing debate in the scientific community. [mehr]

Planetary Group Seminar: The study of the global Heliosheath using Energetic Neutral Atom measurements obtained by the Cassini/INCA imager (K. Dialynas)

  • Datum: 25.11.2015
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Kostas Dialynas
  • University of Athens Department of Physics Section of Astrophysics, Astronomy and Mechanics GREECE
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall
Energetic Neutral Atoms (ENAs) result from Charge Exchange (CE) interactions between energetic, singly charged particles and cold neutral gases that co-exist in a plasma environment. Although the Ion and Neutral Camera (INCA), as part of the Magnetospheric Imaging Instrument (MIMI) suite on board Cassini, is designed to perform ENA measurements originating from the vicinity of Saturn (the Cassini s/c is in orbit around Saturn since 2004), imaging of the Heliosphere (in Hydrogen ENAs) lies well within the instrument capabilities. After 11 years of imaging the heliosphere with INCA, the ENA observations together with the Voyager-LECP in-situ measurements (in overlapping energy bands), have already revolutionized our notions about the formation and interactions of the global heliosphere, providing insights on the plasma processes at ~100 AU that were substantially at variance with previous theories and models. Although the question of how the HS responds to the variability of solar wind conditions and in what manner this response is connected to solar activity through the solar cycle has been addressed partly through modeling, the true manifestation of the HS (moreover in a global scale) to the solar activity have not been directly measured to date. Assessing any proposed interpretation of the HS requires the evaluation of the physical properties of the underlying source proton population in the broad context of the solar wind. Our current analysis on yearly averaged all sky ENA maps over the time period 2003-2014, show that ENA intensities decrease during the declining phase of SC23 by ~x3 from 2003 to 2011 but recover through 2014 (SC24). Similarly, V1,2 ion intensities also decrease and then recover through 2014. The similarity of time profiles of remotely sensed ENA and locally measured ions show that (a) ENA originate in the HS, and (b) the global HS responds promptly (within ~1-1.5 years) to outward-propagating solar wind changes throughout the SC. Further, recovery of the HS during SC24 proceeds asymmetrically from south to north in the general direction of the nose, which may be related to the non-symmetric evolution of solar coronal holes during SC recovery. [mehr]

S3 Seminar: Magnetic ux supplement to coronal bright points (C. Mou)

S3 Seminar: Comparison of Optical and Radio Observation of Coronal Mass Ejection (L. Lu)

MPS Seminar: Sunspot number series: how can we get out of the current mess? (I. Usoskin)

S3 Seminar: Spherical Couette Dynamos (A. Barik)

S3 Seminar: Non Local Heat Flux in Solar Flares (S. de Souza)

S3 Seminar: In-Orbit Calibration of the SO/PHI Instrument (K. Albert)

S3 Seminar: Constraining Differential Rotation in Sun-Like Stars (M.B. Nielsen)

Kometenfieber: Von Steilhängen und Staubfontänen. Die veränderlichen Landschaften des Rosetta-Kometen (C. Güttler)

Öffentliche Vortragsreihe

S3 Seminar: Sub-Grid Approach of Magnetic Reconnection (F. Widmer)

MPS Seminar: Eruptions driven by magnetic Flux Emergence in a Coronal Hole Environment (K. Galsgaard)

Magnetic flux emergence in to an existing coronal magnetic configuration represents one of the simplest ways to generate fast magnetic energy release processes. When the coronal magnetic field contains the favourable configurations different eruptions may take place forming simple jet like features or ejections of flux robes in the from a CMEs. This talk discusses the evolution of a magnetic flux emergence into a simple unipolar magnetic field using 3D non-ideal MHD modelling. The simple model gives rise to a much more complicated temporal evolution than expected. After a longer steady state jet phase the system reaches a phase where five eruptions take place. These are discussed in terms of the stressing of the system as it approaches the instability and the eruptions impact on the ambient magnetic field. [mehr]

Kometenfieber: Die Rosetta-Landemission aus Sicht der Wissenschaft (F. Goesmann)

Öffentliche Vortragsreihe
Here, we present a study of ionospheric convection at high latitudes that is based on satellite measurements of the Electron Drift Instrument (EDI) on-board the Cluster satellites, which were obtained over a full solar cycle (2001-2014). The mapped drift measurements are covering both hemispheres and a variety of different solar wind and interplanetary magnetic field (IMF) conditions. The large amount of data allows us to perform more detailed statistical studies. We show that flow patterns and polar cap potentials can differ between the two hemispheres on statistical average for a given IMF orientation. In particular, during southward directed IMF conditions, and thus enhanced energy input from the solar wind, we find that the southern polar cap has a higher cross polar cap potential. We also find persistent north-south asymmetries which cannot be explained by external drivers alone. Much of these asymmetries can probably be explained by significant differences in the strength and configuration of the geomagnetic field between the Northern and Southern Hemisphere. Since the ionosphere is magnetically connected to the magnetosphere, this difference will also be reflected in the magnetosphere in the form of different feedback from the two hemispheres. Consequently, local ionospheric conditions and the geomagnetic field configuration are important for north-south asymmetries in large regions of the geospace. The average convection is higher during periods with high solar activity. Although local ionospheric conditions may play a role, we mainly attribute this to higher geomagnetic activity due to enhanced solar wind - magnetosphere interactions. [mehr]

S3 Seminar: Forward and Inverse Problems in Asteroseismology (E. Bellinger)

S3 Seminar: Error Budget for Exoplanet Parameers from Asteroseismology (K. Rodenbeck)

S3 Seminar: Galactic Cosmic Rays Tracing in the Magnetosphere of Saturn (A. Kotova)

MPS Seminar: On-Board Computer System Architecture based on Commercial Off the Shelf components (F. Schön)

  • Datum: 28.01.2016
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Friedrich Schön
  • Frauenhofer-Institut für offene Kommunikationssysteme / System Quality Center, Berlin, Germany
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Patrick Bambach

S3 Seminar: Studying the Small Scale Magnetic Features in the Quiet Sun (F. Kahil)

S3 Seminar: Small Scale Chromospheric Fibrils Observed by Sunrise II (R. Gafeira)

MPS Seminar: Solar flares, current sheets, and finite-time singularities in Hall MHD (Y. Litvinenko)

  • Datum: 04.02.2016
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Yuri Litvinenko
  • Department of Mathematics, University of Waikato, New Zealand
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: -

MPS Seminar: Global Programmes in Astronomy Education and Public Outreach (P. Russo)

MPS Seminar: "Wave phenomena in sunspots" (J. Löhner-Böttcher)

Planetary Group Seminar: Water and ices in protoplanetary disks - links to the Solar System (I. Kamp)

S3 Seminar: The Fast Solar Polarimeter Prototype (F. Iglesias)

MPS Seminar: Modelling solar spectral irradiance with a Monte Carlo simulation of active region decay (C. Bolduc)

Kometenfieber: Rosettas Navigation am Kometen 67P/Churyumov-Gerasimenko: vom Anflug bis zur Landung (F. Budnik)

Öffentliche Vortragsreihe

MPS Seminar: Imaging the Earth from sedimentary basins to the deep mantle (A. Fichtner)

Planetary Group Seminar: Constraints on the solar system origin from Galileo, Cassini and Rosetta missions (O. Mousis)

  • Datum: 22.02.2016
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Prof. Olivier Mousis
  • Laboratoire d'Astrophysique de Marseille, Aix-Marseille Université, Institut Universitaire de France
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall

Planetary Group Seminar: Chemistry at the dawn of star formation and links to our Solar System (P. Caselli)

  • Datum: 24.02.2016
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Paola Caselli
  • Max Planck Institute for Extraterrestrial Physics, Garching
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall

Kometenfieber: Kometen und das frühe Sonnensystem (H. Böhnhardt)

Öffentliche Vortragsreihe

MPS Seminar: Looking Back by Looking Up: (Exo)planets and the Earliest History of Earth and Life (E. Gaidos)

Rosetta Seminar: Comparative study of icy patches on comet nuclei (N. Oklay)

Rosetta Seminar: 67P Outbursts (J.B. Vincent)

MPS Seminar: Stellarators, fusion energy, and the Wendelstein 7-X experiment (P. Helander)

The Princeton astrophysicist Lyman Spitzer famously figured out how a magnetic field can be used to confine a fully ionised plasma in steady state. His solution, the so-called stellarator, involves a counter-intuitive twisting of the field without employing an electric current. Six decades later, Spitzer’s idea is put to a billion-euro test in the Wendelstein 7-X experiment of the Max Planck Society. This talk will describe some basic physics and mathematics underpinning stellarators, including the use of “hidden symmetries” to improve plasma confinement. An overview will also be given of Wendelstein 7-X, which after a decade of construction started operation in December 2015 and has already produced plasmas with electron temperatures exceeding 100 MK. If successful, it should produce steady-state plasmas under conditions suitable for extrapolation to a fusion reactor. [mehr]

Public Talk: ESA, die europäische NASA? (J.-D. Wörner)

Planetary Group Seminar: On the characterization of exoplanets with optical phase curves (A. García Muñoz)

S3 Seminar: Characterizing Plasmoid Reconnection by Turbulence Dynamics (F. Widmer)

S3 Seminar: Examination of Historical Ca II K Archives (T. Chatzistergos)

MPS Seminar: Einstein for everyone: a common sense approach (N. Dadhich)

S3 Seminar: Peakbagging of red giants in eclipsing binary systems (N. Themeßl)

Planetary Group Seminar: Debris disks: Comets, asteroids, and dust around stars (A. Krivov)

  • Datum: 10.05.2016
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Alexander Krivov
  • Astrophysical Institute and University Observatory Friedrich Schiller University Jena
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Urs Mall

S3 Seminar: Anomalous Evershed flows: observations and simulations (A. Siu)

Planetary Group Seminar: The chemical heritage of protoplanetary disks (C. Walsh)

S3 Seminar: Modelling of the Protoplanetary Disc (C. Walsh)

Solar Group Seminar: Active region emergence: passive or active? (H. Schunker)

Solar Group Seminar: Coronal abundances by remote sensing: numerical experiments (H. Peter)

MPS Seminar: Stellar Evidence of a Transitional Sun (T. Metcalfe)

S3 Seminar: Analysis of MIRO / Rosetta Data (D. Marshall)

Rosetta Seminar: 67P Microscopic particle morphology (S. Merouane)

S3 Seminar: Inverse Methods for Helioseismology (M. Pourabdian)

S3 Seminar: Stereoscopy of Helioseismic Holography: A Toy Model Study (D. Yang)

S3 Seminar: Flux-flux relations in the solar atmosphere (K. Barczynski)

Rosetta Seminar: 67P Sublimation of dust grains (A. Giquel)

S3 Seminar: Helioseismology of Supergranulation (Z. Ferret)

S3 Seminar: Rotational Lightcurves of Comets and Kuiper Belt Objects (R. Kokotanekova)

Google X-prize: Join a team which participates in the Google X-Prize to land on the Moon

Rosetta Seminar: Alkali metals in 67P dust particles (O. Stenzel)

MPS Seminar: The hydrogen ionization front/stellar photosphereinteraction in Cepheids and RR Lyraes (S. Kanbur)

Solar Group Seminar: Response functions and node-based inversion for NLTE lines (I. Milic)

S3 Seminar: In-situ detectability ofEuropa's water vapour plumes (H. Huybrighs)

Rosetta Seminar: Philae Dust Measurements at 67P (H. Krüger)

Rosetta Seminar: 67P Volatiles as seen by ROSINA (U. Mall)

Rosetta Seminar: The Electric Charging of Nanoparticles AroundSolar-Type Stars (H. Kimura)

Solar Group Seminar: The Sun’s Radiant Energy - Measurements, Models,Mismatches, and Merging (G. Kopp)

Solar Group Seminar: In search of coronal loop footpoints (P. Chitta)

MPS Seminar: Solar Cycle Prediction Using a Surface FluxTransport Model (P. Bhowmik)

Sun Climate Seminar: The contribution of energetic particleprecipitation to ozone and surface climate trends (E. Rozanov)

S3 Seminar: Mineralogy and Geology of the Dantu Crater on Dwarf Planet Ceres (J. Kallisch)

S3 Seminar: Instabilities of the spherical Couette flow (A. Barik)

MPS Seminar: Flux Transport Dynamo Models: Understanding theSolar Magnetic Field generation process (G. Hazra)

The solar cycle is the magnetic cycle of the Sun. Inorder to understand the solar cycle and its properties, we need to understandhow the Sun is generating its own magnetic fields and organizing them. The FluxTransport Dynamo model is the most successful model to understand the solarmagnetic field generation process. But it has some inherent limitations. Inmost of the dynamo models, a single cell meridional circulation is used butthere is some recent observational evidence that the meridional circulation ofthe Sun may not have a single cell structure rather it might have a double cellor multi-cell structure. I shall discuss that the new observations are notimposing any serious threat and our model works perfectly fine. Many processesin this models are inherently 3D. In 2D we can model them very crudely by usingsome simple parametric form. So I shall explain the next generation 3D Flux TransportDynamo model which will be more realistic. The build up of solar polar fieldsusing this model will also be discussed. Apart from that I shall discuss thathow inclusion of observed high resolution non-axisymmetric convective flows inour model from SDO Dopplergram data affects the behaviour of theBabcock-Leighton process and helps us to put a better constraint on the surfacediffusivity. [mehr]

MPS Seminar: Information Transfer - from the Solar System to Exoplanets (L. Kaltenegger)

MPS Seminar: Formation of comets, planets, moons in our solar system (O. Mousis)

MPS Seminar: Effects of Coronal Eruptions Observed in the Chromosphere (M. Kirk)

Planetary Group Seminar: Exploring the Perimeter of the Heliosphere using IBEX and Voyager Observations (G. Glöckler)

Forty-five years after they were launched, the two deep space probes of the Voyager Interstellar Mission are now exploring the distant nose region of the heliosphere in two different directions at distances from ~85 to ~135 astronomical units from the sun. Voyager 1 (V1) measurements of the magnetic field, plasma waves and energetic particles, have revealed numerous surprises, forcing a rethinking of our concepts of the heliosphere and its interaction with the local interstellar medium. Most heliospheric researchers now believe that V1 entered interstellar space in late August 2012 and are constructing models based on this assumption. However, we find, using pressure balance and measurements of the low energy neutral hydrogen atoms spectrum, that the strength of the magnetic field that VI is currently observing is only half of the strength of the local interstellar field. This and other observational evidence leads us to conclude that Voyager 1 is not yet in interstellar space but rather remains in a most unusual region of the heliosheath. [mehr]

S3 Seminar: Reconstructions of Solar Irradiance on the Millennial Timescale (C. J.Wu)

MPS Seminar: Seismic investigations of the Lithosphere, western North Island, New Zealand (J. L. Dimech)

MPS Seminar: Plasma-Neutral Interaction - Conductivity and Field-Aligned Currents (A. Otto)

MPS Seminar: Introduction of NICT space weather researchactivities (M. Ishii)

  • Datum: 14.11.2016
  • Uhrzeit: 11:00 - 12:00
  • Vortragende(r): Mamoru Ishii
  • National Institute of Information and Communications Technology (NICT), Japan
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Hardi Peter

MPS Seminar: The VO And Why It Matters To You (M. Demleitner)

MPS Seminar: Why does the solar wind turn the wrong way, sometimes? (A. Otto)

MPS Seminar: High-precision spectroscopy and fundamental parameters of stars (M. Bergemann)

MPS Seminar: Observing stellar dynamos in action (T. Hackman)

MPS Seminar: Vortex flows and magnetic fields in the quiet Sun (I. Requerey)

S3 Seminar: Slender Ca II H fibrils observed by Sunrise / SuFi (R. Gafeira)

S3 Seminar: Supergranular waves (A. Barekat)

Solar Group Seminar: tba (A. Künstler)

Solar Group Seminar: How investigating shear-driven turbulence helps to understand stellar interiors (V. Witzke)

MPS Seminar: Solar Limb Oscillations as Rotation Tracers and the Near Surface Shear (J. Kuhn)

  • Datum: 05.01.2017
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Jeff Kuhn
  • Institute for Astronomy, University of Hawaii, Maui, Hawaii, USA
  • Ort: MPS
  • Raum: Auditorium
  • Gastgeber: Aaron Birch
The HMI limb data pipeline is creating new information about the outer few hundred km of the solar atmosphere. The high signal to noise limb displacement and brightness oscillation data have yielded some surprising results. One of these is evidence of the largest rotation shear in the sun in the photosphere. This radial gradient is evidence of a stress that seems only possible from the radiated photon angular momentum. This seminar describes the limb oscillation data and the physical arguments that support a "photon brake" acting in the solar photosphere. [mehr]

MPS Seminar: Exploring the Diversity of Planetary Magnetospheres (E. Bunce)

MPS Seminar: Space Missions and Future Challenges (H. Dittus)

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