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Researching atoms sheds light on stars and galaxies


Malmö University researchers have made a breakthrough in understanding how atoms interact with light.

Carina Nebula. Photo by Nathan Smith, University of Minnesota/NOAO/AURA/NSF.

Henrik Hartman and Per Jönsson are two of the physicists working on mapping the chemical elements found in stars. They are joined by PhD students Asli Pehlivan and Madeleine Burheim.

“Our research merges atomic physics with astronomy. We map different elements; essentially, we look at atoms to see how the electrons inside them structure around the nucleus. Atoms are sensitive to different colours of light, so by finding out more about their structure, we can learn what type of light they emit and absorb,” explains Hartman.

“The ultimate aim of our research is to provide knowledge about the constituents of the universe; how stars and galaxies are formed and where all the chemical elements, which are also found in our own bodies, come from.”

Supernovas and star deaths

The four-year research project, titled Experimental and computational atomic astrophysics, is backed by funding from the Swedish Research Council.

“It’s been a year since we started and we have already made some milestone discoveries,” Hartman says.

Specifically, the team has completed the mapping of two particular elements: magnesium and silicon. This means they now understand how electrons form around the nucleus of the atoms in these elements and can determine the balance of magnesium and silicon in stars.

The research is based on calculations as well as experiments, using a light measuring facility called a spectrometer.

“What’s wonderful is that when you know a lot about atoms, you can interpret stars in detail. Understanding the atom can take the observation of stars to a new level. For example, it can allow us to map a single supernova or death of a star and see what elements are contributed to the next generation.”

Thinking big

Hartman is also interested in looking at elements produced in big stars.

“My favourite star — Eta Carinae — is one we also work on. It’s one of the largest stars in the universe with a luminosity five million times greater than the light of the sun. There are many different types of elements produced in these kinds of massive stars.”

In the future, the research team hopes to tackle the more heavy, complex elements such as titanium, nickel and gold.

“Applying physics to astronomy is fascinating because it removes the limitations of radiation, velocity, temperature and pressure. You can find some odd things in space,” Hartman adds.

Text: Maya Acharya

Last updated by Maya Acharya