Erika Pakštienė is a full-time faculty member in the Institute of Theoretical Physics and Astronomy at Vilnius University. She graduated from Vilnius Pedagogical University (now Vytautas Magnus University) Department of Physics & Chemistry, followed by a master's in the same university's Physics and Astronomy department. After these, she pursued a Ph.D. at Vilnius University's Institute of Theoretical Physics and Astronomy with the title “Extinction of the Earth's atmosphere in multicolour photometry”. Throughout this period, she worked as a physics teacher in a secondary school, an engineer, and a researcher.
Her main research field is asteroseismology – the study of stellar interiors through their pulsations. She began her scientific career investigating pulsating white dwarfs and, in recent years, has focused on stars with solar-like oscillations, using them to determine stellar ages and evolutionary stages and to improve our understanding of the evolution of the Milky Way Galaxy.
She has participated in numerous international observing campaigns, including the Whole Earth Telescope (WET) network. Her scientific interests also include eclipsing binary stars and exoplanets. She was the first researcher in Lithuania to initiate observations of exoplanet transits.
Alongside her research, she has been actively involved in education and science outreach. She has served as an evaluator at the International Physics Olympiad, developed astronomy assignments for the distance-learning physics school FOTONAS, contributed to the development of two STEAM educational activity methodologies for the STEAM Centre in Vilnius, co-authored educational materials for physics teachers, contributed astronomy chapters to educational publications, and authored numerous popular science articles on astronomy.
She was also among the five Lithuanian scientists nominated for the 'Honour of Lithuania' award for her involvement in the exoplanet discovery by microlensing (AT2021uey, paper).
The asteroid 270903 Pakstiene (2002 TO303, JPL Small-Body Database) discovered by Kazimieras Černis was named in her honour in 2021.
1- You have extensive experience with telescope observations, teaching how to utilize it, and processing its signal. What are your
a. The most memorable experience during your observation campaigns,
It is difficult for me to identify a single most memorable observing experience. There have been many of them, because I started my first scientific observations almost thirty years ago. Many of my first experiences in observational astronomy remain among my strongest memories. One of them was my first observing run with the 165 cm telescope at the Molėtai Astronomical Observatory, when I felt both pride and responsibility as I operated such a large scientific instrument for the first time. Similar feelings accompanied my first observing campaigns at the Teide and La Palma observatories in the Canary Islands, where I had the opportunity to work in an international environment, meet colleagues from different countries, and observe the sky from some of the best observatories in the world. Another memorable aspect of observing campaigns was the strong sense of cooperation in observatories around the world. In the years before long-term space-based photometry became available, continuous observations were possible only through international collaborations. Many observers, often separated by thousands of kilometres, worked together as one team, each contributing a small part to a much greater scientific effort. This shared purpose made such campaigns especially rewarding. However, sometimes the most memorable moments are not the observations themselves but unexpected natural phenomena. One such event happened in 2023 at the Molėtai Observatory. While preparing for remote observations, I noticed unusually bright patches in the sky on the observatory webcams. At first, I did not understand what I was seeing. After reviewing a time-lapse video, I realized that they were very bright aurorae. Such events are relatively rare in Lithuania, and on that occasion the aurora was visible across almost the entire sky. It was one of the most impressive natural phenomena I have ever observed at Molėtai Observatory. I also clearly remember my surprise during a night observing run at the Teide Observatory when my car became covered with ice while the air temperature was still +8°C. As a physicist, I can explain the process, but even for a physicist, it was quite unexpected.
b. The one that taught you the most
In reality, the greatest lessons are learned not when everything goes smoothly, but when you face unexpected situations; new instruments, new observing techniques, technical failures, or unfavorable weather conditions. Over the years, I have learned that successful observations depend not only on astronomical knowledge but also on discipline and careful work. One of the most important lessons I have learned, and one that I always pass on to beginning observers, is the importance of having a clear checklist. This is especially important at the end of an observing run, when observers are often tired, and it becomes easy to forget an important step. For example, someone may forget to stop telescope tracking or overlook another procedure required for the safe shutdown of the system. Such mistakes may put expensive observatory equipment at risk and can create unnecessary problems for the next observing session. Perhaps the most important lesson I learned is that successful observations depend as much on practical experience and attention to detail as on scientific knowledge. Many problems cannot be solved by theory alone and require quick decisions based on experience gained at the telescope.
2- How was your experience working on the “Whole Earth Telescope” network studies?
The Whole Earth Telescope (WET) network was my gateway into asteroseismology. Although my PhD research was related to atmospheric extinction, during a summer school organized by our institute, Prof. Jan-Erik Solheim from the University of Tromsø in Norway suggested applying the atmospheric extinction correction method I had developed to WET observations. That became my first step toward asteroseismology. In 2002, I participated in the WET conference in Naples, Italy, where I presented my method. I became fascinated by variable stars, the diversity of their pulsations, and the possibility of studying stellar interiors through asteroseismology. This field later became one of my main scientific interests. I participated in WET campaigns in several different roles. I carried out observations both at the Molėtai Astronomical Observatory and with the Nordic Optical Telescope on La Palma. I also had the opportunity to work at the WET headquarters in Ames, Iowa, USA, where I became familiar with the coordination of an international observing campaign, real-time data processing, and the organization of a global observatory network. Later, I also organized two WET observing campaigns dedicated to the DAV white dwarf PG 2303+243. I subsequently performed the asteroseismic analysis of the data collected by multiple observatories worldwide. This allowed me to experience WET not only as an observer and campaign participant, but also as a campaign organizer and principal investigator. This experience showed me how observatories around the world can operate as a single instrument in order to achieve continuous observations. Although today we receive a large amount of high-quality data from space missions such as TESS, international observing campaigns remain important. The main difference is how they are organized has changed. Today, coordination, communication, and data exchange are mostly done remotely, allowing researchers from different countries to collaborate efficiently.
3- You worked on many different types of astronomical objects. What are the hurdles, remarks, your favourite among them, and especially if there was a challenge after changing the type of astronomical object to study?
Yes, during my career, I have observed many different types of astronomical objects, including pulsating white dwarfs, eclipsing binary stars, exoplanet transits, artificial Earth satellites, rotating asteroids, and others. Some of these observations were related to my own research, while others were part of projects led by other researchers. I always find it exciting to start working with a new type of object because each raises different scientific questions and requires understanding different physical processes. If I had to choose a favourite group of objects, it would be objects with variable brightness. When an object does not vary, a single observation is often enough. When it varies, every new observation can provide additional information. Whether it is a pulsating white dwarf, an eclipsing binary, or an exoplanet transit, changes in brightness over time contain valuable information about the physical properties and internal structure of these objects. For this reason, light-curve analysis has always been one of my favourite areas of astronomical research. If I had to mention one specific object, I would choose an eclipsing binary system discovered at the Molėtai Astronomical Observatory in 2019. It is a particularly complex system. The stellar orbits are eccentric; the stars experience tidal distortions when they approach each other, and one of the components is a pulsating Delta Scuti star. As the stars periodically approach each other, their gravitational interaction distorts their shapes, and we observe changes in the system's brightness. Such systems are not easy to study, but they can provide very accurate results because we obtain additional information both from the orbital geometry of the eclipsing binary and from asteroseismology. We are still studying this system. The biggest challenges usually come not from the type of object itself but from observing conditions and technical limitations. For example, when observing geostationary satellites or space debris, the calculated position is often not accurate enough. If the field of view of a telescope is too small, the object has to be searched for in neighbouring sky fields around its predicted location. Such observations sometimes resemble a game of hide-and-seek. Another constant challenge is the weather. Even carefully planned observations can fail if clouds arrive at the most important moment. Astronomers cannot control the weather or the behaviour of the objects they observe. Astronomical objects do not follow a work schedule. Eclipses, transits, and other short-lived events occur whenever nature decides they should occur, regardless of weather, weekends, or holidays. We sometimes say that astronomers do not work according to a schedule; they work according to the sky. As a result, this profession teaches patience, flexibility, and the ability to adapt. It is also common for astronomers to end their messages with the traditional wish: “Clear skies.”
4- You have papers with single to several, to multiple, to many authors, and you joined collaborations with different numbers of people. What are your remarks on working in different group sizes?
During my career, I have worked both independently and in small, medium-sized, and very large international research groups. Each type of collaboration has its own advantages and disadvantages. Working alone provides more freedom to make decisions and choose the direction of the research. However, it also means you have to do everything yourself, from observations and data analysis to interpreting the results and preparing the paper. This often makes the research process considerably slower. In addition, there are fewer opportunities for regular discussions and feedback from colleagues. In my opinion, small and medium-sized groups, with roughly 5 to 15 active researchers, are often the most efficient. In such groups, every member can make a significant contribution to the final result. Research decisions are discussed within the team, and results are usually obtained and published more quickly. At the same time, large international projects are also very important. In astronomy, it is often necessary to organize long-term observing campaigns involving many observatories and researchers from different countries. In such cases, a long author list usually reflects not simply formal participation, but the need to combine the efforts of many people to collect the required data. Without this type of collaboration, many studies would simply not be possible. Therefore, I believe that the most important factors are not the size of the group, but clearly defined goals, good communication, and a clear understanding of each person's role within the project. Although large international collaborations are often unavoidable in astronomy, I personally feel most comfortable working in a smaller research group.
5- How can we make science popularization/outreach activities successful?
Although I consider myself primarily a researcher rather than a science communicator, I believe that the public should have the opportunity to learn what scientists do and why their work is important. Over the years, I have participated in various educational activities and have seen that people are usually most interested when they can get a glimpse of real scientific work. In my opinion, successful science outreach should show why science matters and how it is connected to everyday life. Audiences are often more interested in stories, discoveries, and the process of scientific research than in formulas or technical details. Direct involvement is also very important. Opportunities to ask questions, participate in observations, experiments, or other hands-on activities help people stay interested for much longer. When someone becomes part of the process, science becomes more meaningful and easier to understand. At the Molėtai Astronomical Observatory, we organized summer schools dedicated to astronomy outreach activities. Students worked in small groups and prepared short videos on different astronomy topics. It was interesting to see how differently people could present the same scientific information. Each group found its own way of engaging the audience, and the final results were often surprisingly creative. This experience showed once again that successful science outreach requires not only knowledge but also creativity. In addition, the best results are often achieved when several people work together and combine different ideas and perspectives. Today, social media and digital platforms also play a very important role in science outreach because they allow us to reach much larger audiences than traditional events alone.
6- What is your current research interest that intrigues you?
There are many areas of astronomy that interest me. However, throughout most of my career, asteroseismology has remained the field that fascinates me the most. Asteroseismology provides a unique opportunity to study the internal structure of stars through their pulsations, because information about stellar interiors cannot be obtained through direct observations. What I particularly enjoy is that every variable star is like a puzzle. As we analyse its pulsations, our understanding of the star gradually develops, piece by piece, much like solving a jigsaw puzzle. Although modern methods are becoming increasingly automated, the analysis of many variable stars still requires a scientist's experience, intuition, and creativity. I am also very much looking forward to the European Space Agency's PLATO mission. It will provide an enormous amount of high-quality photometric data and open new opportunities not only for asteroseismology but also for studies of exoplanets and other variable objects. More generally, what I find most exciting about astronomy is that there are still so many unanswered questions. The more we learn, the more new questions appear.
7- Do you have any suggestion for astrophysics graduate students?
One of the most important pieces of advice I would give to students today is to learn how to use artificial intelligence wisely. AI has become an easily accessible tool that can help with learning, generating ideas, searching for information, understanding difficult concepts, and even suggesting new research directions. However, it is very important to maintain critical thinking. AI should not replace a student's ability to analyse information, evaluate sources, or solve problems independently. It should be used as a tool and assistant, not as a substitute for your own thinking or as a friend who does your homework for you. My second piece of advice would be to find a topic that genuinely interests you. Scientific research requires a great deal of time, patience, and persistence, so motivation becomes extremely important. If you have a clear goal and are truly interested in what you are doing, it becomes much easier to overcome difficulties.