Astronomical News DOI: 10.18727/0722-6691/5182

Fellows at ESO

Rosita Kokotanekova Rosita Kokotanekova

My path in began before I can remember, and it has led to my becom- ing an ESO Fellow thanks to the support of a long list of teachers, mentors, and friends. However, in the first place, I owe my inspiration to be an astrophysicist to my parents, Joanna Kokotanekova and Dimitar Kokotanekov. They have devoted their lives to outreach and teaching extra- curricular astronomy classes to high- school students in Haskovo and Dimitro- vrad in .

When my brother Georgi and I were little, our parents took us along to almost every observation they organised: astrophoto­ graphy sessions, observations of partial After my second year at Jacobs Univer- and Akos Bogdan. This project was a and total solar and lunar eclipses, meteor sity — in 2011 — I joined the Laboratory continuation of my work with Elke showers, Venus and Mercury transits — of (LASTRO) at the École ­Roediger and would not have been pos- you name it. Later, I participated in the Polytechnique Fédérale de Lausanne sible without her generous efforts to Bulgarian National Astronomy Olympiad, (EPFL) in Switzerland where I worked with expand my skill set and to develop my as well as in two International Astronomy Frédéric Courbin, Cécile Faure and resumé. My work at CfA was extremely Olympiads in Crimea (2004) and China Georges Meylan on a six-week project to interesting and introduced me to X-ray (2005). I also completed my first small discover strong gravitational lenses in and radio observations of cluster research projects and had my first con- optical images from the Wide Field Cam- centres. In addition to the amazing sci- tact with ESO, both through the Catch a era 3 (WFC3) on the Hubble Space Tele- ence environment at CfA, that summer Star contest 1. scope (HST). I greatly enjoyed the friendly also brought me many wonderful experi- environment at LASTRO and the Obser- ences which I shared with old and new These experiences convinced me that vatory of Geneva, as well as living so friends in Boston. I would like to become an astrophysicist close to the Alps, so I decided to go back and in my bachelors degree I chose for another two-month project the year The next step of my career was deter- to study Earth and Space sciences at after. mined by a lucky coincidence. Straight Jacobs University Bremen, . after the internship at CfA, I started look- This programme was a great choice Straight after completing the second ing for PhD positions. While I was fasci- because it allowed me to learn more internship, I joined the AstroMundus nated by extragalactic astronomy, and in about geosciences and environmental ­Masters Course in Astrophysics. This particular by X-ray observations of galaxy studies alongside astrophysics. Besides, program took me on a two-year journey clusters, I was not looking forward to the education at Jacobs University had through four different countries, at the yet another relocation. This motivated me a hands-on approach and prepared me University of , the University to keep my eyes open for other PhD very well for a research career. of Padua, University and opportunities that would let me stay in ­Göttingen University. After three semes- ­Göttingen or at least in Germany. Then After only my first year at Jacobs, I con- ters of courses covering almost every suddenly, in November 2013, the press tacted Marcus Brüggen and Elke area of astronomy, I spent the final was filled with reports about the unex- ­Roediger to ask whether I could work semester of the programme researching pected complete disintegration of comet with them on a small research project X-ray weak quasars with Wolfram ISON. This got me very intrigued because over the summer. During this summer ­Kollatschny at Göttingen University and up to that point I had not had any courses project and my subsequent bachelors Luka Popović in Belgrade. This project in Solar System science and I naively thesis research, Elke taught me a great gave me my first experience of spectros- thought that small bodies were very well deal about galaxy clusters and hydro­ copy and taught me how to work inde- studied, and that their behaviour could be dynamical simulations, but most impor- pendently — a skill that has come in predicted with great accuracy. tantly introduced me to the research handy during my PhD, and especially ­process — how to start with an idea and during the ESO fellowship. That same week, a friend sent me a link find the right collaborators, and how to to the home page of Pedro Lacerda who complete it and produce a high-quality I had reserved the AstroMundus summer was looking for PhD students to join his scientific publication. break in 2013 for a three-month intern- newly formed research group in Come- ship at the Harvard Smithsonian Center tary Science at the Max Planck Institute for Astrophysics working with Ralph Kraft for Solar System Research in Göttingen.

The Messenger 178 – Quarter 4 | 2019 67 Astronomical News Kokotanekova R., Facchini S., Hartke J., Fellows at ESO

After reading his webpage and meeting Stefano Facchini him in person, I was captivated by his way of thinking and his approach to doing research. He also managed to convince me that minor planets in the Solar System hide many unanswered questions.

I joined Pedro’s research group in Octo- ber 2014 and chose to work on his large observing programme with ESO’s New Technology Telescope (NTT) at La Silla. The programme was awarded 40 nights with the ESO Faint Object Spectrograph and Camera 2 (EFOSC2) to study the rotational light curves and surface col- ours of up to 60 Trans-Neptunian Objects (TNOs). In only the third week of my PhD, I went for my first observing run at ­thesis. At ESO, I chose to take up sup- Stefano Facchini La Silla with my other PhD advisor Colin port astronomer duties on VLT/UT3 as Snodgrass. This was the first time I had my functional work and now, after four Since I was a kid, I have had a passion the chance to spend time with Colin, and shifts in Paranal, I have finally completed for science — in, I would say, two differ- I quickly became convinced that my PhD my extensive training as a support ent flavours. First of all, I have always was going to lead to many exciting pro- astronomer. My duties in Paranal are very been touched and fascinated by the jects and fun trips. Soon after that run, I challenging but extremely rewarding. On beauty of nature, by the constantly vary- enrolled as a PhD student at the Open the one hand, the trips to Chile are physi- ing shades of colour in the sea, by the University, UK and Simon Green joined cally exhausting, but on the other hand I powerful heights of the Alps during a the supervision team as a third advisor. have become part of the amazing Paranal hike in the summer, or by the fragility of While most people are lucky to find community, and I have already learned field flowers in my grandparents’ farm. I one good advisor, I was fortunate to work even more about the telescopes­ and strongly believe that my sense of awe in with three great mentors on my PhD. instruments than I had hoped. front of the beauty and apparent order of nature is one of the main driving forces Like most PhDs, mine did not go as As this is the first year of my first postdoc, that led me to become a scientist. Sec- planned. The data from the large pro- the past twelve months have been full ondly, I have always been interested in gramme turned out to be very challeng- of many new adventures in the world of and fascinated by mathematics, show- ing to analyse, and instead I focused research. Probably the most rewarding ing a strong propensity towards scientific on publishing our side projects on photo- one of them was mentoring a talented topics since my first years at school. metric observations of Jupiter-family and enthusiastic summer student — comet (JFC) nuclei. This led to many new Abbie Donaldson — during the first ESO My passion for the night sky grew later, ideas and accepted observing proposals Summer Research Programme (see during the first years of high school. I on nine different telescopes. The work on page 57). For the coming year, I have an have a clear memory of one evening that project did not always go smoothly ambitious plan, which among other being in the countryside close to Lake either, but in the end resulted in a coher- things includes: completing a few pro- Como in with a friend of mine and ent PhD thesis, which I managed to write jects on TNOs and JFC nuclei; organising his father. His dad started pointing at mainly during an eight-week window while the second ESO Summer Research Pro- the sky and naming the constellations being stuck at home with a broken foot. gramme together with the other fellows; that were visible during that summer securing more observing time for the evening. What impressed me the most is Ever since my first trip to La Silla, I had ideas I developed over the past year; four that he had a familiarity with the beauty been hoping to follow in Colin’s footsteps trips to Paranal; many important confer- of the sky we were looking at; he could to become an ESO Fellow. When the time ences and meetings; more time spent recognise and name stars, whereas for came, and I was about to look for post- working with collaborators; and last but me everything was beautiful but totally doc positions, my advisors encouraged not least, a couple of vacations that my unknown. From that evening, I started me to put my ideas together and design husband and I have been looking forward studying the constellations of the north- a research programme to propose for the to for years. ern hemisphere, and I developed an ESO fellowship application. enthusiasm for getting to know and being able to describe the beauty of the sky. This led to an offer from ESO and I Links started my fellowship in November 2018, I continued to follow my passion for 1 ESO Catch a Star contest: http://www.eso.org/ two months after I defended my PhD public/outreach/eduoff/cas/ ­natural sciences, and I started attending

68 The Messenger 178 – Quarter 4 | 2019 physics courses at the University of Milan most important thing I learnt is to ask years and to even more exciting in Italy. The choice of the subject of my myself the question that Cathie asked me discoveries! undergraduate studies was the easiest many times: “how do you understand this choice of my life by far! Even though equation empirically?” In other words, I loved many topics, in particular solid how is this mathematical formula describ- Johanna Hartke state physics and statistical mechanics, I ing a physical phenomenon in a simple opted for a masters degree in astrophys- way? This way of looking at the mathe- It is hard to pinpoint exactly when I dis- ics. What attracted me the most is that matical formulation of physics has covered my passion for astronomy. I grew this subject required one to study and changed my way of doing theory forever, up in the northern German countryside, understand many areas of physics: gen- leading me to understand a physical so even though the skies were relatively eral relativity, classical mechanics, quan- ­process with very simple principles. dark, it was often cloudy. My parents tum mechanics, molecular physics, etc. had a small refracting telescope which All aspects had to be taken into account! Towards the end of my PhD, however, I stood forgotten in front of the living room One of the topics I loved the most was felt that I was lacking something, so window, waiting for clear skies. However, compact objects — in particular the book much so that I wondered whether to con- as a child, I was more drawn towards Black holes, white dwarfs and neutron tinue to do research. At some point, I the piano that stood right next to it. One stars: the physics of compact objects by understood that I was missing a closer of my first (of many) career goals was Teukolsky and Shapiro — where the connection to observations, and I tried to to become a pianist, then followed by a three main forces of physics interplay to find a postdoc that could allow me to desire to be a teacher, an actress, produce beautiful objects such as neu- develop this new side of research. I was a mathematician, and eventually, a tron stars and black holes. lucky enough that Ewine van Dishoeck physicist. invited me to join her group at the Max For my masters thesis, I decided to work Planck Institute in Garching, and the Following a summer school on quantum with Giuseppe Lodato, who had recent- three years with her group have been physics for gifted high-school students ly arrived in Milan from the UK. During my key for who I am today as a scientist. In the year before I graduated high school, I thesis, I started working on a research particular, with her I broadened my was convinced my career lay in theo­ topic that is what I still work on seven expertise, and started working on thermo- retical physics. A year later, I enrolled to years later: protoplanetary discs and chemical models of discs, and more study physics at Jacobs University, a planet formation. The thesis project was directly on observations at different small, international university in Bremen. I deeply theoretical, and we were trying wavelengths (from millimetre to ultravio- had a great experience living on campus to answer the question: what would hap- let). Those same years, since 2015, have with students from over a hundred differ- pen if a protoplanetary disc orbits around been transformational in my field. The ent countries, but soon realised that the- a binary that is misaligned with respect ­tremendous capabilities of the Atacama ory was not my calling. While I enjoyed to the disc itself? Developing semi-­ Large Millimeter/submillimeter Array experimental physics lectures, I was also analytical models and hydrodynamical (ALMA), in terms of sensitivity and angular simulations, we figured out that the disc resolution, together with ­high-performance Johanna Hartke can warp, and in some extreme cases, infrared imaging instruments such as it can break into separate annuli. At the SPHERE, completely revolutionised time I approached this as a theoretical the field of planet formation, showing game. How impressed I was years later images of the environments where plan- when high-resolution images of proto­ ets form with unprecedented detail. planetary discs started to be available, in Doing research in a field that was being particular thanks to the VLT instruments transformed every six months by a new NAOS-CONICA (NACO) set of observations has been among and Spectro-Polarimetric High-contrast the most exciting experiences of my life. REsearch (SPHERE), and sig- natures of these broken discs were During the last year, I have been working directly observed as we had predicted! at ESO as a fellow. This has allowed me to move even more towards observa- The masters thesis was such a great tional astronomy, getting even more experience that I decided to keep on involved with ALMA (through my func- doing research with a PhD. To do this, I tional work) and with other instruments managed to go to Cambridge in the UK, on the VLT (such as SPHERE, MUSE, to work with Cathie Clarke on a variety X-Shooter). To me ESO is the perfect of topics, and in particular on the effects environment to do astrophysical research that ultraviolet radiation from massive in the way I love: led by observations, stars can have on the evolution of proto­ but with a strong theoretical background planetary discs in young massive clus- to interpret the data and to predict what ters. The PhD was mostly theoretical; the to expect. I look forward to the next two

The Messenger 178 – Quarter 4 | 2019 69 Astronomical News

notorious for clumsy accidents in the lab. Telescope on La Palma. During our five sis. Since the PN.S is a visitor instrument, However, there was one topic I excelled nights at the telescope, we experienced we spent many afternoons leading up to in and that was astrophysics. Unfortu- first-hand how it felt to be an astronomer our observations tuning the filters and nately, the astronomy branch was closed and the patience it required in case of aligning the CCDs in the instrument arms. in my second year of study. The subject bad weather! Yet I had found a new pas- Six months later, I got the opportunity was not uppermost in my mind anymore, sion. It was rewarding to see our project to join my ESO Fellow mentor during his and struggling with the prospect of grow from a little idea in our heads to duties at Paranal observatory. At last I becoming a researcher, I seriously con- typing the coordinates of targets into the was convinced that the next step for me sidered reverting to one of my earlier telescope, and to finally present the sci- would be an ESO Fellowship in Chile career choices: becoming a teacher. I ence to our peers after reducing the data. to get even more exposure to the had just made it to the state final of a One year later, I again found myself on ­forefront of astronomical research and youth music competition in Germany and La Palma, this time observing at the instrumentation. teaching music and physics in high ­William Herschel Telescope for my master school seemed like the perfect combina- thesis project with Eline Tolstoy. And here I am now. I have just completed tion of subjects for me. the first year of my fellowship and there- It was clear that I wanted to pursue a fore the first 80 days and nights as a sup- Everything changed, however, when I PhD in . In the port astronomer on Paranal. It has been was selected for a summer internship at same year, I was accepted into the Inter- an exciting year with a steep learning Mount Stromlo Observatory of the Aus- national Max Planck Research School curve! I am part of the Multi Unit Spectro- tralian National University. For the first (IMPRS) on Astrophysics in Munich for a scopic Explorer (MUSE) instrument oper- time, I got an insight into the day-to-day three-year studentship at ESO under the ations team and currently work on a life of a researcher and could work inde- supervision of Magda Arnaboldi. For my ­project to investigate how well the adap- pendently on a small project on stellar PhD, I investigated how the halos of tive optics improve the image quality. It streams in the . My supervisor early-­type grow through mergers is great working in an international and Ken Freeman introduced me to the beauty and . This is a challenging interdisciplinary team. I particularly enjoy and elegance of galaxy dynamics. All endeavour, as the closest early-type the ritual of watching the sunset from of a sudden, I could appreciate classical ­galaxies are already millions of light-years the platform before the night starts. I also mechanics as a great tool to describe the away, but the faint halos are very recently started to experiment with astro- motions of the stars. After the internship, extended on the sky. I therefore use a photography. I like to share the wonders I abandoned my idea to go to the con- particular type of stars — planetary of the night sky with my friends in the servatory and instead focused on finding ­nebulae — which are like green beacons city, where due to the bright lights, one an opportunity to carry out my bachelor in the sky, and whose velocity can be can barely make out the Southern Cross. thesis research project in astronomy; so measured even at a distance of hundreds When I am not observing or working I found a placement in nearby Groningen of millions of light-years. from Vitacura, one is likely to find me to work with Amina Helmi. rehearsing music. While living in Munich, I enjoyed being in the middle of one of I was a soprano with the Münchner I decided to stay at the Kapteyn Institute the astronomy hubs in and got to Motetten­chor and spent a good part of for another two years to complete my participate in many exciting seminars my leisure time in churches and concert Master of Science, thoroughly enjoying a and conferences that were taking place halls in the region. Now in Santiago, I curriculum centred on astronomy. Soon on campus. I travelled again to La Palma have again taken up singing, although on an opportunity came up to enroll in a to observe the halos of giant elliptical a smaller scale. It is a relaxing balance course on observational astronomy which ­galaxies with the custom-built Planetary to the academic world and a great way to was to take place at the Isaac Newton Nebula Spectrograph (PN.S) for my the- practise my Spanish.

In Memoriam

ESO staff member, Cristian Herrera ator (TIO) in 2001. During his 18 years at 10 years, leading the night crew and González, sadly passed away in August Paranal, Cristian worked on most of the was the coordinator of the Instrument 2019 and will be much missed. He joined telescopes, instruments and subsystems Operations Teams activities for the oper- ESO and the Science Operations Depart- of the observatory. He held the role of ators during his shifts. ment as Telescope and Instrument Oper- nighttime TIO Coordinator for more than

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