KOLOKVIJI ZAVODA ZA FIZIKU DEPARTMENTAL COLLOQUIUM

22 October 2008, 13:00, room 11 CoRoT - IN SEARCH FOR TERRESTRIAL PLANETS Günther Wuchterl, Thüringer Landessternwarte Tautenburg, Germany Abstract: The space telescope CoRoT was successfully launched in December 2006 from Baikonur and is the first astronomical instrument developed to detect terrestrial planets. It continuously and simultaneously records the brightness of 12000 stars to catch planetary transits. During such events when a planet passes through the line of sight between its host star and the Earth, a small decrease in the stars apparent brightness lasting for a few hours signals the existence of another world. Stars with planetary suspects are then investigated from the ground to determine their properties and those of their companions. So far four planets an a very strange object, right in the gap between planets and Brown Dwarfs have been secured and fully characterised. The long, uninterrupted lightcurves of CoRoT are also used for Asteroseismology and open up planetary studies that up to now were only possible inside the solar system. The CoRoT-astronomy is explained and its latest results are discussed.

In collaboration with Info zona - informativni centar za mlade 23 October 2008, 20:00, Jerina 1 (iza Sv. Frane) HOW MANY STARS CAN WE STILL SEE? A global survey of night sky brightness in the International Year of Astronomy 2009 Günther Wuchterl, Thüringer Landessternwarte Tautenburg, Germany Abstract: A global survey of night sky brightness in the International Year of Astronomy 2009 asks people to look at their sky near home to asses the state of the world's night skies by simple naked eye observations of Umi and Ori taking a few minutes. The campaign relies on regional (multi-languages and -cultures) public communication and support centres aided by a self-propagating centralised web-infrastructure. Eye-estimates are anchored in a network of low cost luxmeters, capable of automatically and continuously recording all natural night-illumination levels. The goal is to make 1000 million people look at their home skies, collect a million observations of visual limiting magnitude and create the first global assessment of the state of the night sky by anchoring the estimates in the thousand luxmeter network distributed to (public) observatories, planetariums, astronomy clubs and schools. In short: 1 Bio people, 1 Mio observations, 1000 luxmeters for a year. A call for a 2009 participation is made and the "how to" is explained including a demonstration of one of the Luxmeters.

29 October 2008, 13:00, room 11 HOW STARS DIE: EXPLOSIONS, EJECTIONS, AND STELLAR ART Bruce Balick, University of Washington, Seattle, USA Abstract: Using spectacular Hubble Space Telescope images to illustrate our understanding of the physics of stellar evolution and to guide our thinking where theory clearly fails, we will explore the future of the Sun and many stars like it: how they grow, shrink, flash, and enrich the Milky Way with carbon and nitrogen. The talk includes a description how expected changes in the Sun will affect the fate of our planet over the course of the next 5-10 billion years.

In collaboration with Info zona - informativni centar za mlade 06 November 2008, 20:00, Jerina 1 (iza Sv. Frane) THE HUBBLE SPACE TELESCOPE AT 20: LIFE AND REBIRTH IN 2009 Bruce Balick, University of Washington, Seattle, USA 2009 is the year of the telescope: 400 years ago Galileo observed the Moon and established modern astronomy, and for 20 years the Hubble Space Telescope observed the cosmos and revolutionized our understanding of how the Universe works. Hubble has produced a spectrum of exciting results in its lifetime -- findings that have thrilled the public and the science community alike. Next February the next and final shuttle servicing mission to Hubble will add two new cameras, repair two others, and replace many of the components that should extend Hubble's science capabilities for another ten years. Bruce Balick, a user of the Hubble since 1996 and a member of one of its instrument design teams, will present a brief history of Hubble and describe the renovations planned for 2009. He will also illustrate the highlights of Hubble research in modern astrophysics with some of the most spectacular images obtained in the past ten years.

05 November 2008, 13:00, room 11 THE LARGE SYNOPTIC SURVEY TELESCOPE: The Next Generation Astronomical Survey Chuck Claver, National Optical Astronomy Observatory, USA Abstract: In the history of astronomy, major advances in our understanding of the Universe frequently arise from dramatic improvements in our ability to accurately record, measure, and catalog astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. The Large Synoptic Survey Telescope (LSST) promises the great leap in optical astronomical survey capability. LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. The project is scheduled to have first light in 2014 and the beginning of survey operations in 2015. The LSST data products will be available to the public and scientists around the world -- everyone will be able to view and study a high-definition color movie of the deep Universe.

12 November 2008, 13:00, room 11 MASERS IN THE SKY: FROM STAR FORMATION TO BLACK HOLES Moshe Elitzur, University of Kentucky, Lexington, USA Abstract: The name MASER is an acronym for Microwave Amplification by Stimulated Emission of Radiation (lasers, which have become ubiquitous in everyday life, operate on the same principles as masers, only involving visible Light instead of Microwave radiation.) While the construction of a laser or maser device requires special effort on Earth, somehow the effect occurs naturally in interstellar space. Masers are observed in a variety of astronomical sources, ranging all the way from nearby comets to faraway galaxies. When detected, maser radiation provides information, unavailable otherwise, regarding small details in the structure of the emitting astronomical source. Intense H2O maser emission has been used for the first detection of a supermassive black hole at the center of an active galaxy. This talk will provide an overview of the maser phenomenon and present a number of examples of fascinating maser sources.

26 November 2008, 13:00, room 11 OILY FINGERPRINT OF THE EARLY LIFE ON EARTH Tanja Bosak, Massachusetts Institute of Technology, USA Abstract: Molecular fossils are remnants of the actual lipid molecules that formed the cell membranes of ancient organisms. Because all organisms have membranes, most old fats may not tell us anything more than that some living organisms were present in the past. Fortunately, relatives of a disreputable lipid cholesterol are more informative and come to the geochemist's rescue. Old fats, it turns out, also contain various cholesterol-like ringed lipids (called polycyclic terpenoids) that are amazingly stable under both acidic and basic conditions, at elevated temperatures, and when faced with other adverse conditions that destroy most organic compounds in sediments. I will discuss current research related to the biochemical, physiological and geochemical mysteries surrounding these modern and fossil fats.

In collaboration with Info zona - informativni centar za mlade 27 November 2008, 20:00, Jerina 1 (iza Sv. Frane) ŽIVOT NA MLADOM PLANETU Tanja Bosak, Massachusetts Institute of Technology, SAD Prvih tri milijarde godina na Zemlji, okoliš na našem planetu nije bio nimalo slican današnjem. Zemljom su vladali mikrobi, a život se odvijao vecinom u morima. Znanstvenici se aktivno bave odgonetanjem kada i kako su razni mikrobijalni procesi poput fotosinteze, stvaranja metana i dobivanje energije iz organske materije i sulfata zauvijek promijenili lice Zemlje. Buduci da mikrobi ne ostavljaju velike i prepoznatljive fosile poput biljaka i životinja, prepoznavanje mikrobijalnih struktura i procesa se zasniva na geokemijskim, fizikalnim, geologijskim i biologijskim metodama. Intenzivna interdisciplinarna istraživanja u tim podrucjima u zadnjih desetak godina su znatno doprinijela otkrivanju mnogih novih tajni zapisanih u starim stijenama.

18 December 2008 OPTICAL PROPERTIES OF BIOMOLECULES-NANOCLUSTERS HYBRID SYSTEMS FOR BIOSENSORS AND BIOCHIPS OPTICKA SVOJSTVA BIOMOLEKULA-NANOKLASTERNIH HIBRIDNIH SUSTEMA ZA BIOSENZORIKU I BIOCIPOVE Vlasta Bonačić-Koutecký, Humboldt-Universität zu Berlin, Germany Abstract: ....

22 December 2008, 13:00, at Kopilica Astronomy seminar: PRVA SVJETLOST SVEMIRA, GLEDANA OKOM LOFAR TELESKOPA Vibor Jelić, Kapteyn Instituut, Groningen, The Netherlands Jedan od glavnih dogadjaja koji je oznacio ranu povijest Svemira (z~1100) predstavlja razdvajanje zracenja od barionske materije. U tom trenutku Svemir postaje providan, te reliktno zracenje iz toga doba danas vidimo kao pozadinsko zracenje svemira (CMB). Obzirom da u svemiru jos nema formiranih izvora zracenja, svemir ulazi u epohu mraka (tzv. ``Dark Ages''). Nekoliko stotina milijuna godina kasnije, formiraju se prvi izvori svjetlosti (npr. zvijezde, mini-kvazari) te pocinju (re)ionizirati medugalakticki prostor (tzv. ``Epoch of Reionization, EoR''). Danas znamo da je vecina medugalaktickog prostora ionizirana, ali i dalje ostaju pitanja: sto?, kada? i kako? je (re)ioniziralo Svemir. U predavanju ce biti objasnjena fizika EoR epohe Svemira, dokazi (re)ionizacije Svemira, te izazovi LOFAR-EoR radio-astronomskog eksperimenta da pomocu vodikove 21-cm linije odgovori na gore navedena pitanja.

22 December 2008, 14:30, at Kopilica Astronomy seminar: COLLIMATION OF JETS FROM YOUNG STELLAR OBJECTS Miljenko Čemeljić, ASIAA (TIARA), Taiwan ...

14 January 2009, 13:00, room #11 ON THE WAY TO FINDING A SECOND EARTH - EXTENDING RADIAL VELOCITY PROGRAMMES INTO THE NEAR INFRARED Andreas Seifahrt, University of Göttingen, Germany Abstract: I will give a short introduction into existing programmes to detect extrasolar planets. A special emphasis will be given to radial velocity (RV) surveys, todays most succesfull method in finding other worlds. I will outline the technical challenges and the prospects for further improvements, both at existing facilities and with new spectrographs, such as CRIRES, a new high-resoluton near-infrared spectrograph at the VLT on Paranal, Chile.