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KIS Research Plan 2009-2013

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KIS Research Plan 2009-2013 Understanding the Sun Kiepenheuer-Institut fur¨ Sonnenphysik Research Plan 2009 – 2013 Es gibt wenig Menschen, die ein gescheites Gesicht machen konnen,¨ wenn sie nach der Sonne sehen. Georg Christoph Lichtenberg (1742–1799) November 2009 Kiepenheuer-Institut fur¨ Sonnenphysik Schoneckstraße¨ 6 D-79104 Freiburg Tel. +4976131980 Fax +497613198111 email [email protected] URL www.kis.uni-freiburg.de Editors: S.V. Berdyugina, O. Steiner Cover picture: GREGOR, the new 1.5 m solar telescope that is being set up in Tenerife by a consortium of German research institutes. The Kiepenheuer-Institut coordinates the construction and future operation. Photo R. Volkmer (KIS) Back cover: telescope design of GREGOR as shown on the cover page of the KIS research plan 2002–2007 Summary UNDERSTANDING THE SUN is the key to understanding the stars and the habitability of planets. Thanks to its close vicinity to Earth, the Sun is the only star that can be scrutinized in detail. On the Sun we see a wealth of structure and activity, far beyond of what can be studied in the laboratory. On the other hand, the Sun is our home star. It is a source of energy for life on the Earth, and its radiation and activity directly influences the conditions on our planet. While solar physics undergoes an unprecedented development, the following major issues remain unsolved: ∙ Origin, structure and evolution of the Sun’s magnetic field ∙ Hydrodynamic structure of the convection zone and operation of the dynamo ∙ Heating of the outer atmosphere ∙ Coupling between the Sun and Earth The Kiepenheuer-Institut fur¨ Sonnenphysik conducts research on fundamental astrophysics, with a particular emphasis on the Sun, and focuses its activity at solving the major issues in solar physics. Research projects of the Kiepenheuer-Institut are organized into three main areas. The solar magnetism is the common thread through and link between these research foci: RESEARCH FOCI FINE STRUCTURE of the PHOTOSPHERE and CHROMOSPHERE: This focus aims at understanding the granulation, magnetic structure formation, magneto-convective processes in sunspots as well as structure and dynamic of the chromosphere and heating processes in the outer atmosphere. GLOBAL MAGNETIC ACTIVITY: This research focus deals with the origin, evolution, and energetics of magnetic fields in the Sun and stars and the coupling of the Sun-Earth system. HIGH-RESOLUTION SPECTRO-POLARIMETRY: This research focus aims at the elaboration of high-sensitivity techniques for imaging, spectroscopy and polarimetry of the solar surface structures. The institute operates the German solar telescopes on Tenerife, Spain, and provides a strong theoretical foundation for interpretation of data and modeling physical processes in the solar interiors and up to the upper atmosphere. With the 1.5-m telescope GREGOR, to be completed in 2010, the Kiepenheuer-Institut will have one of the world’s most powerful solar telescope. The Kiepenheuer-Institut cooperates with German partner institutes, as well as with leading research institutions in the US, Europe, and elsewhere. Its research program is consistent with the strategic plan Perspektiven der Erforschung von Sonne und Heliosphare¨ in Deutschland, formulated in 2003 by the German research community of solar and heliospheric physics. Summary 3 RESEARCH TOOLS Research in the Kiepenheuer-Institut relies on the cooperation between experimental and theoretical physicists, and on the expertise in the instrumental development. Theoretical research as well as data analysis is supported by the computer facilities of the institute, including a net of workstations and PCs and a Linux cluster. External computing resources are being used additionally. Instrument development at the Kiepenheuer-Institut focuses on ground-based telescopes. In addition, the KIS participates in balloon and space projects. The main facilities and projects include: ∙ The 1.5-m telescope GREGOR, a technological challenge, with the first multi-conjugated adaptive-optics system. GREGOR will provide observing conditions superior to all present solar telescopes. ∙ The Vacuum Tower Telescope (VTT) on Tenerife with Echelle spectrograph, Fabry-Perot interferometers, polarimeters, and an adaptive-optics system. ∙ The 10-cm telescope ChroTel, which portrays the chromosphere of the Sun simultaneously in three spectral lines. ∙ The European Solar Telescope (EST), the next-generation solar telescope in Europe, for which KIS leads several work packages in the design study. ∙ The 4-m Advanced Technology Solar Telescope (ATST). The Kiepenheuer-Institut will contribute to this US project with the experience gained from GREGOR and intents to build a Visible Tunable Filter (VTF) for ATST. ∙ The 1-m balloon-borne telescope SUNRISE. KIS contributed to this international cooperation the image stabilization and telescope alignment system. ∙ The SOLAR ORBITER. This ESA-F2 mission will get closer to the Sun than all previous space probes. KIS plans to contribute to the image stabilization system. EDUCATION and PUBLIC OUTREACH KIS represents astrophysics in the curriculum of the Faculty for Mathematics and Physics of the Albert-Ludwigs-Universitat¨ Freiburg. Teaching includes lecturing, practical training at the Schauinsland Observatory, student seminars, and research trainee positions. The KIS conducts an undergraduate and graduate program at the institute that attracts a steady influx of young researchers funded through various third-party sources. Public outreach activities include tours at the Schauinsland Observatory and at the VTT, information days for high school students, a teacher’s seminar, contacts with amateur astronomers, public lectures, press releases, and the World Wide Web. 4 Summary Project schedule for the instrument developments at the Kiepenheuer-Institut: 2009 2010 2011 2012 2013 German Telescopes at the Teide Observatory Telescope GREGOR 2nd gen instruments GREGOR@night Standard operation VTT LFC, helioseismology ChroTel Participation in Next Generation Ground Based Facilities Design Studies EST (Phases 1 and 2) FPI development Visible Tunable Filter ATST FDT Contribution to Airborne and Space Based Facilities Balloon Flights Sunrise CWS Supos Phase A Study SO-PHI FS Unit design development construction commissioning science operation Summary 5 Contents Understanding the Sun 9 Research Capacities 11 Research Foci 13 FineStructureofthePhotosphereandChromosphere 13 Global Magnetic Activity 19 High-Resolution Spectro-Polarimetry 24 Instrument Development 29 Telescopes and Instrumentation 29 Relation with Science Goals 33 Research Service 35 Operation of the Tenerife Observatory 35 Education and Public Outreach 37 Education and Training 37 Public Outreach 38 Index of Abbreviations 39 Understanding the Sun Solar physics deals with the internal and atmo- the convection zone. The rotation stimulates the spheric structure, evolution, and dynamics of the solar dynamo which builds up the global magnetic Sun. The light and warmth of the Sun are the foun- field of the Sun in an 11-year activity cycle with dation for the habitable zone of our solar system in alternating polarity. which life on our planet can flourish. Beyond the knowledge of the Sun as an astrophysical object, The solar magnetic field manifests itself in a variety it is for this reason that understanding the Sun is of phenomena in which magneto-convection – the significant for life on Earth, similar to the way dynamic interaction between convective flows and geoscience, meteorology, or climatology are. Our the magnetic field in an electrically conducting deep interest in exploring the Sun roots in its direct fluid (plasma) – plays an outstanding role. The influence on Earth and its habitability. The Sun spectrum of the magnetoconvective processes in is the primary source of energy for the multitude solar physics extends from the creation of magnetic of terrestrial life forms yet to be discovered in fields in the dynamo process, its rise through the the distant universe. Furthermore, solar physics convection zone and emergence in the solar atmo- is a fundamental component in the education of sphere, the formation of concentrated magnetic astrophysicists. It comprises the foundation of structures in the photosphere, to the magnetically general astrophysical research, due to the fact that induced transport of mechanical energy into the the Sun, as a result of its proximity to us, is the outer atmosphere where it contributes to the only star that can be studied in detail. heating of the corona and the acceleration of the solar wind. The Sun shows a much more complex behavior than would be expected from an ideal model of a The magnetic field and its structure can be gas sphere in the hydrostatic equilibrium. This can observed most precisely in the photosphere and the be attributed first of all to the convective gas flow chromosphere. There it appears in the form of, e.g., that takes place over the outer 29 % of the Sun’s sunspots, pores, magnetic knots, and small-scale radius and is visible as granulation on the surface magnetic flux elements. The spatial dimensions of the Sun, as well as to the rotation of the Sun. of these phenomena extend over several orders of magnitude, from more than 100 000 km to less The interaction of the two motions causes the than 100 km. Consequently, surface magnetism rotation to become differential, i.e., it varies with takes on a prominent role in the research of the the heliographic latitude and with the depth in Kiepenheuer-Institut. Time instant of a three-dimensional
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