The prints are also helping us to distinguish different types of substructures. For instance, if you’re looking at a filament in two spatial dimensions, it might actually be a two-dimensional sheet that you’re just looking at on its side. And that’s hard to make out in a flat picture — or even a computer simulation. But with the 3D prints, we’re able to see these sheetlike structures extending through the clouds, and this raises tantalizing possibilities. Maybe some of the filaments we see are actually sheets, or perhaps a sheet is sort of a precursor to a filament. We’re really interested in piecing together all of the stages that lead up from the formation of a molecular cloud to the birth of a star.
Lately, we’ve seen one of these star-forming regions in a new light with the James Webb Space Telescope. What was your reaction to the Carina Nebula photo?
The JWST image of the Carina Nebula is stunning — so beautiful. It is images like these that make me keep falling in love with astronomy. I often tell students that the space between stars is not empty, and a picture like this really tantalizes the imagination when looking at the night sky.
It’s interesting to compare this new image of Carina to the previous Hubble image of the same region. The new image reveals so much of the internal structure of the cloud: We see gas, faint young stars and proto-stellar jets where we didn’t before. With near-infrared eyes, we begin to peer closer into the hearts of stellar nurseries.
In addition to studying star formation, you also helped discover the first candidate planet outside the Milky Way last year. How did that happen?
The vast majority of known exoplanets have been discovered by inferring their presence from variations in the light of their host star. We see the star’s light dip in brightness when a planet crosses in front of it, or shift in frequency if a planet’s tugging on it. Our group, led by Rosanne Di Stefano, decided to take a new approach to searching for exoplanets. Rather than optical light, we looked for bright X-rays given off by a certain type of compact binary star, where one of the companions is a neutron star, white dwarf or black hole. Because this X-ray emission is so intense and so compact, when a planet passes in front, it should produce a pretty noticeable signal. A nice consequence of this technique is that it could make it possible to detect these signatures at much greater distances, which is how we discovered the first exoplanet candidate in another galaxy — too far away to detect using traditional methods.
Why bother studying planets in other galaxies when there are so many nearby?
We can never make assumptions about the entire universe based on what’s happening in our own backyard. In addition to being much farther from Earth than all known exoplanets, this candidate was also detected around a star that’s at a much later stage in its evolution than we’re used to. That’s a situation we might not have accounted for if we used observations only from our own galaxy.
Similarly, we don’t want to have a theory of star formation just for the Milky Way — we want a universal theory. I like studying dwarf galaxies because not only are they the most common type of galaxy in the universe, they’re also excellent astrophysical laboratories for star formation in environments different from the Milky Way. Dwarf galaxies have a lower abundance of heavy elements compared to more massive galaxies like the Milky Way. In this respect, we think they may be similar to some of the universe’s earliest galaxies, which may have had a dearth of heavy elements.
Your research has centered on studying astronomical processes that are notoriously difficult to visualize. How does your identity as an artist affect the way you ask and answer scientific questions?
I have this sketch I drew years ago — a self-portrait of myself touching a star. Imagination is a huge part of what it means to do science, and I often imagine what it would be like to be up close to these environments. As both an artist and an astronomer, you have to be a careful observer of what’s happening in nature and really try to understand what things look like. I think that my affinity for images and my desire to visualize things definitely feed into my scientific curiosity. After all, astronomy is really the science of light and images.
Ultimately, art is just another dimension of my identity — and it probably influences my work in ways more mysterious than I understand.
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