Final Report Summary - SAS-RRL (Space AsteroSeismology & RR Lyrae stars) The focus of the Marie Curie project “SAS-RRL” lies in “SpaceAsteroSeismology” and “RR Lyrae Stars”. In the framework of this project, Dr. Katrien Kolenberg has spent nearly three years (06/2011-04/2014) at the Harvard-Smithsonian Center for Astrophysics in Cambridge MA, USA, and the return phase (05/2014-04/2015) at the Institute of Astronomy of the KU Leuven, in Belgium. The data gathered with the Kepler (2009-2013) satellite have not only boosted the discovery of planets orbiting other stars, including those resembling Earth, but they have also opened a window into the inner workings of the parent stars themselves. In particular, stars that oscillate -- and it turns out many do -- yield clues that allow us to probe their structure with a set of research tools called asteroseismology. At the Harvard-Smithsonian Center for Astrophysics (CfA), the location of the outgoing phase, a large group of scientists is working on the analysis and interpretation of Kepler data. Their principal aim is planet detection. However, the signals of a planet and its variable host star are intricately interwoven. The applicant has been working in the field of asteroseismology for about a decade. Her focus has been on photometric and spectroscopic studies of pulsating stars, in particular RR Lyrae stars, and techniques to unravel the pulsations of stars. She has been chairing the Kepler RR Lyrae working group of the Kepler Asteroseismic Science Consortium, working on the analysis, interpretation, and publication of the Kepler data for this type of variable stars. Her visit to the CfA has facilitated collaboration between scientists in the USA and Europe. In Europe, asteroseismology has grown into a blossoming research field, indispensable for assessing the properties of stars, also those harboring planets. Therefore, her return to the KU Leuven, which hosts one of the world’s excellence centers in asteroseismology, has been well-timed and very fruitful.Complementary to the research connected to the Kepler and other space missions, the applicant has continued her research on RR Lyrae stars, through a multidisciplinary, multifaceted approach. Through interaction with scientists at the CfA she has gained expertise in neighbouring research fields, in particular X-ray studies and model atmospheres used for spectroscopic analysis. The acquired skills are being passed on to students currently working under the mentorship of Dr. Kolenberg in Belgium and abroad.The following paragraphs highlight some of the obtained scientific results.Dr. Kolenberg has obtained groundbreaking results for the study of RR Lyrae stars in the course of this Marie Curie project. She has also successfully worked on other types of variable/pulsating stars observed with the Kepler mission.The Kepler data of RR Lyrae stars have led to some groundbreaking new insights into the inner workings of these astrophysically important objects. The list of publications concern the discovery of period doubling in RR Lyrae itself and its implications for our understanding of long-standing mysteries concerning the RR Lyrae stars, the multiperiodicity of first-overtone RR Lyrae stars, multiple modulations and the discovery of higher-order radial overtone pulsations and additional, probably non-radial modes. Just like the outgoing phase, the return phase of the project “SAS-RRL” has been very successful. The skills gathered during the stay at CfA were applied and used to prepare publications during the return phase.Concerning the impact of the Marie Curie project for the field of research and the career development of Dr. Kolenberg, we can conclude the following:• This Marie Curie fellowship has allowed her to significantly expand the scope of her research. At the CfA, she has gained new insights into stellar modeling and X-ray spectroscopy techniques, while at the same time contributing her knowledge of asteroseismology to the Kepler mission. Dr. Kolenberg has not only gained interdisciplinary knowledge but also a greatly enhanced publication record. The value of the proposed training/mobility period in the US are greatly appreciated by her European collaborators. The increased interaction between American and European teams is beneficial for all the research groups involved. Moreover, the training the applicant has received has made her uniquely competent in a fast-growing field of astrophysics. In summary, the proposed project has given the applicant the final boost to become an independent and internationally competitive researcher in her area of interest. • The Kepler project provides an ideal opportunity for cross-Atlantic collaboration. The expertise of European asteroseismologists has been indispensable for the interpretation of stellar data resulting from the Kepler mission, including the characterization of stars harbouring planets. This fellowship has been a conduit between US and European researchers with complementary expertise that is likely to last for many years to come. • This Marie Curie project fits tightly with Europe's research interests. It includes all the major aims specified in the Work Program for “Structuring the European Research Area”, i.e. (I) transfer of research competencies, (II) consolidation and widening of researchers’ career prospects, and (III) the promotion of excellence in European research. The CfA hosts a flourishing community of astronomers specialized in an unusually diverse array of disciplines. Dr. Kolenberg’s star at this renowned institution has strengthened the network of institutions across Europe and the US, connecting EU member states and the US, and accordingly provided an excellent base for high-quality research. • With the acquired skills and an enhanced publication record, the applicant has returned for the return phase to the Instituut voor Sterrenkunde at the K.U. Leuven, Belgium, which hosts a renowned asteroseismology center, one of the largest worldwide, where she has continued research and started new fruitful collaborations.• As an example of an additional benefit, at the time of writing (June 2015), Dr. Kolenberg is organizing a visiting program for exchange of researches. This has only been possible thanks to the networking done in the framework of the Marie Curie grant.• Dr. Katrien Kolenberg was recently selected to become co-chair of the RR Lyrae and Cepheid working group for the upcoming (2017 launch) TESS mission (TESS Asteroseismic Science Consortium), in many ways a continuation of Kepler (with its Kepler Asteroseismic Science Consortium). This Marie Curie fellowship has raised the visibility of European expertise amongst the global scientific community. The scientific output of this project so far has been published in international peer-reviewed journals and presented at international meetings by the researcher and her collaborators. Considering that it addresses questions that are of great interest to the international scientific community, the outcome of our work has not gone unnoticed (e.g. participation and first prize in EURAXESS North America Science Slam 2013, YouReCa Science Slam winner 2014, FameLab Belgium finalist (2nd prize) 2015). Thus, the project is also helping to attract and educate a new generation of scientists in Europe, thus aiding the development of the European Research Area. Added to this, Dr. Kolenberg was shortlisted for the Marie Curie actions Prize for Nurturing Research talent (2014).In June 2015, Dr. Katrien Kolenberg was appointed as a faculty member (Associate Professor 20%) at the University of Antwerp in Belgium.Dr. Kolenberg is very grateful for the opportunities and successes that the exceptional opportunity of the Marie Curie Fellowship has brought to her.
