Above: Images of nearby galaxies taken from the Hubble Space Telescope and the James Webb Space Telescope.
Astronomy professor Anne Jaskot ’08 uses the James Webb Space Telescope to explore previously unknown details about the universe.
The James Webb Space Telescope—the largest ever sent into space—launched in December 2021 and took a month to reach its orbit position 1 million miles from Earth. With its ability to detect light beyond what’s visible to the human eye, its first images stunned and captivated people worldwide when they were released on July 12, 2022.
Scientists the world over submitted nearly 1,200 proposals to conduct research using the Webb. Among the 266 approved projects was one from Williams astronomy professor Anne Jaskot ’08, who is studying six nearby galaxies in hopes of under-standing how stars, black holes and supernovae lit up the gas in early galaxies.
The Webb telescope “is suddenly opening a new window on the universe that we didn’t have access to before,” Jaskot says. “This is the first time I can see galaxies like this glowing in infrared and get that piece of the puzzle.” Jaskot was awarded 24 hours on the telescope, distributed between March and June. Her research is supported by a three-year, $82,150 grant from the Space Telescope Science Institute and includes funds for an undergraduate assistant.
By studying the nearby galaxies, Jaskot hopes to gain a better understanding of our own galaxy as well as the conditions of the early universe. Her research might also lead to more knowledge about how stars form, evolve and die.
“One of the cool things about astronomy is that you can look back in time,” she says. “If you look far enough away, light has taken so long to reach you that you actually see the universe as it looked billions of years ago.”
Since childhood, Jaskot has been interested in the ability to look deep into the past, whether at a billion-year-old fossil or using a telescope orbiting the Earth. She majored in anthropology and astrophysics at Williams, where she first studied galaxy gases and used spectroscopy—the science of decoding the atomic makeup of objects and gases from the light detected with a telescope.
She still recalls her first time using the Hubble Space Telescope as a graduate student at the University of Michigan. Located outside the Earth’s atmosphere, Hubble offered a much clearer view than telescopes on the ground.
“It was so exciting to see something that had been just a blur from the ground suddenly crystallize,” Jaskot recalls. “One of the things we learned was how compact and tiny the galaxies were. They were these tight knots of actively forming stars. I remember being surprised with how things were so much tinier than I expected them to be.”
Unlike ground telescopes, Hubble and Webb are more reliable. Rather than a telescope user adjusting for, say, the challenges of a cloudy night, Jaskot receives an email notification from Webb that a galaxy she’s interested in has been observed and that the data is available for download.
The datasets show a spectrum of light split into varying colors, each coming from a different atom, which “would tell you about the composition of the galaxy,” Jaskot says. The patterns reveal not only the presence of elements like neon and sulfur, which could result from star gases turning into stars, but also the specific kinds of elements.
“We’re looking for—and we think we might see—quadruply ionized neon,” Jaskot says. “Kicking four electrons off an atom requires energies so high that stars can’t produce them. Something like supernova explosions or black holes would have to be present in our galaxy to give us that type of neon.”
Jaskot says she chose the six galaxies she’s studying because “they’re similar in their composition, but they also show some interesting differences in terms of what energies of light seem to light up their gas. We’ll compare our findings with some of the model predictions to see which scenarios match what we’re observing. Do we see the energies we would expect if it were just hot stars? Or if the energy is from material heated by a black hole?”
As she awaits the last datasets from all six galaxies, Jaskot says she is immersed in the magic and mystery of a previously unseen corner of the universe.
“It’s always fun when you’re not doing any scientific measurements—when you’re just looking for the first time to see what you have,” she says. “There are things you expect to see and things that you weren’t looking for but which will now become a part of the story.”