Astrophysicist Thomas Bensby is an observational astronomer of stars and the director of graduate studies at Lund University’s department of physics. Thomas uses spectroscopy, a technique used to analyze a star’s spectrum, to trace where stars come from or if they were born together.
As a child, Thomas Bensby didn’t know his current profession would be researching the studying stars of the Milky Way. Although he enjoyed astronomy and space, his family didn’t have a strong academic background, and he ended up working at construction sites.
– I was working as a supervisor at construction sites in the early 90s, but then in the bad times, the construction crashed in Sweden in ‘91. I was just starting my career into that, and everyone who had just started had to go, says Thomas Bensby.
Thomas decided to enroll in math courses at Lund University to earn certificates within the construction business to work on more advanced projects, hoping that Sweden would recover from the construction crash. However, the crash continued, and Thomas returned to the university to study more courses.
While finishing the math courses, Thomas began taking physics and astronomy courses in the evenings. Thomas wrote his master’s thesis in astronomy but received a degree in physics since the university did not offer an official astronomy program. He also received a master’s degree in Education after completing a one year program.
–Then I worked as a teacher for a year, and I realized that maybe I want to do astronomy instead. So, then I started my PhD here in Lund.
– So if there had not been bad times in the construction business in the early 90s, I would probably not be an astronomer, says Thomas.
After completing his PhD in 2004, Thomas went to Ann Arbor, Michigan in the United States to complete a three year postdoctoral fellowship. Upon completing that fellowship, he did another three year fellowship in Chile with the European Southern Observatory (ESO). Occasionally while in Chile, visiting astronomers get mixed results due to uncontrollable factors.
– I worked as a support astronomer down there, helping visiting astronomers, who came there, preparing their observations for the night. Spending the night in the control room together with them, sometimes just waiting for the clouds or the wind to go away so we could start observing. It might never happen, and then they went back home either with or without data, says Thomas Bensby.
In 2010, Thomas returned to Lund from his ESO fellowship and has remained here ever since. He is currently using spectroscopy to study the stars of the Milky Way. Using spectroscopy to understand the spectrum of stars allows researchers to study the process of light splitting into wavelengths, making small dips visible to learn the elemental composition within each star. Measuring the strengths of wavelengths can identify how much of each chemical element is present in each star.
– With that we can try to trace or figure out where stars come from and where they belong. If they have been born together they have very similar chemical compositions, says Thomas Bensby.
Using spectroscopy allows Thomas to specialize in understanding where all the stars in the Milky Way came from. A new instrument known as 4MOST, 4-meter Multi-Object Spectrograph Telescope, at the European Southern Observatory in Chile will allow more observational astronomers to further expand their research.
4MOST will allow researchers to observe a greater number of stars at once while also monitoring the spectrum and DNA samples of those stars. Over a five-year period, researchers study these stars to construct a chemical map that allows astronomers to match the family’s sub-stars within the Milky Way and identify their origins.
– Having a good map, the structure of the Milky Way is a very important first step in order to try to understand how the Milky Way formed and where it came from. And ultimately, we want to understand how spiral galaxies like the Milky Way in general form, as the Milky Way is just one of billions of spiral galaxies in the universe, says Thomas Bensby.
As exciting as results and new advancements are, mapping the galaxy is a long and slow process. Although there may not be as many challenges in research, observational astronomers experience delays from various factors.
– If you’re an observational astronomer, you’re applying for observing time with the big telescopes on the Canary Islands or down in Chile. It might be that you get observing time, you do preparations for a few weeks, you travel down to Chile, you have your two nights of observing, but it’s cloudy. You spend a few nights on the mountain getting nothing and then you travel back home. And that’s it, so that has happened, says Thomas Bensby.
Another challenge, specific to Thomas, is balancing administrative work and research time. Besides working as a researcher, Thomas is also the director of graduate studies at the department of physics, and he has to split his time between both. Although balancing research time can be challenging, Thomas finds it rewarding to be able to contribute to shaping future researchers.
– I’m the director of graduate studies here at the physics department, so that takes 40 percent of my time. The physics department has 160 PhD students, so that is occupying a lot of time. And then we have teaching, and we have supervision of bachelor students and master students.
– It’s becoming more and more difficult to have the undisturbed research time that you might need and that you want. Even if you have a few free time slots during the day, it’s not that you can just sit down for that hour and say, now I shall do research. You cannot just go from one thing to another, says Thomas Bensby.
Although setbacks in research may be irritating, pursuing a passion is achievable even if it takes time. Thomas encourages people to pursue their interests and anything that excites them.
– I would suggest to do it and whatever interests you should do. You should not listen to those that say it’s not a good time to be an astronomer because there are no jobs. If you’re good at something, I think eventually you will get into that field, says Thomas Bensby.
