Assistant Professor of Astronomy Seth Redfield will be observing “cool stars” through the Hubble space telescope, thanks to a generous grant awarded by the Space Telescope Institute last month. Redfield sat down with The Argus to discuss the grant, mapping the interstellar medium, and the possibilities of extraterrestrial life.
The Argus: So congratulations on your recent success—what sort of research are you planning to use the grant for?
Seth Redfield: Well, the Space Telescope Science Institute is an institution built around running the Hubble space telescope, so the grant is tied to observations with the Hubble itself. The project I received the grant for is a large international collaboration that has received a total grant of something like $750,000, of which I’ve received something around $50,000. It’s a big grant for me, but it’s also a really amazing observation opportunity as well. Hubble only has so much time each year to look at objects in the cosmos, and there are about 10 times more requests to use the telescope than there are opportunities available. It’s a very competitive process! All told, this whole program has received about 156 orbits with the Hubble, which is about six percent of all the time it has this year, which doesn’t seem like a ton on its own, but for a single group, it’s pretty extraordinary. The program I’m working with is called a treasury program because it’s a large grouping of people and the goal of the project is to observe about a dozen stars in and about our galaxy. We’re wondering how they work, what their atmospheres are like, how those atmospheres act on the space around them, and so on—they all tie back to how stars evolve over time. Depending on the mass of the star or the different balance of elements, stars can take very different evolutionary tracts, and that’s what we’re exploring.
A: Is there anything special about the stars you’re studying?
SR: These are cool stars—we divide stars based on their temperatures, between cool stars and hot stars. Our sun, for example, is a cool star, meaning that it is relatively small and cold. We’re looking at these stars because it helps to put our own in relative context. The things that we see the sun doing—are they common? Are they rare? It’s these sorts of questions we’re thinking about. We are very much linked to the sun—life itself is dependent on it—so we’re very interested in how these stars interact with the planets orbiting them.
There’s something called space weather—weather that happens on suns that can have effects on planets—things like solar flares, aurora borealis, which are caused by charged particles from the sun. Flares can be harmful to astronauts, space stations, and satellites, so there’s this whole industry about understanding space weather. We can study our sun in extreme detail, but we also need to study other stars in order to put it in some context.
A: Does this relate to your research at the University?
SR: Well, I have two major research areas, the first being on extra-solar planets, which involves understanding how other stars interact with the bodies orbiting them. The other is studying the interstellar medium, which is the gas and dust in between stars. In terms of the treasury project, I’m involved in measuring how the interstellar medium affects the light and compositions of stars.
A: Are you trying to get University students involved with your work?
SR: Well, we have a great graduate astronomy program here, so I have two graduate students working with me, as well as an undergrad who I’m working with on their senior thesis. We just went to the annual meeting of the American Astronomical Society and presented some of the research we had done. While none of these students are directly involved with the treasury project, the next generation definitely will be, once the results of this research start materializing. But these students are working on exo-planet and interstellar medium problems, which are, of course, really important to the work we’ll be doing.
A: What are your plans for the future?
SR: Well, there are always more proposals to write, so the cycle continues [laughs]. But in terms of this project and the interstellar medium, I see this as moving towards fully rendering a three-dimensional characterization of the gas and dust that surrounds our sun and other stars. Right now, we only have glimpses of what’s going on in certain areas. However, with this data set and other sets I’m in the process of acquiring, we’ll start to fill in these gaps and put together a fuller map of the interstellar medium. It’s like making a map before we knew about the Americas. There’s not a lot of information and there are big holes in our knowledge, but it’s very exciting. The other way I see this going is in our understanding of how planets and stars interact. It’s really important in an egocentric way, just in the fact that we are on a planet circling around a star—how they interact is really central to our wellbeing.
We’re also on the cusp of finding all these planets around other stars. About 15 years ago, we didn’t have the technical expertise to discover them, so we presumed they were out there, but we lacked the hard evidence. That’s changing, and today we know of some 500 planets around other stars. We’re going to find a lot more of them and many of them are going to be planets about the size of earth, so understanding how they work and how they’re interacting with their star will be really critical to questions of whether life could exist on them. That’s a really exciting question to be pondering in any context, let alone a scientific one.