Each month, we’ll be spotlighting members of the Mauve Science Programme, sharing insights into their research, scientific journeys, and how Mauve supports their work.
We begin the series with a Q&A featuring Christopher M. Johns-Krull, Professor of Physics and Astronomy at Rice University and an early member of the Mauve Science Programme. In this Q&A, he reflects on his research, the value of long-term observational data, and how Mauve is helping advance our understanding of stellar and planetary systems.
Can you please introduce yourself?
“I am an astronomer studying star and planet formation. I am primarily an observational astronomer who uses high-resolution spectroscopy to study newly formed stars, their near-circumstellar environments, how they accrete and/or throw off matter, and to look for evidence of forming planets around these stars. Most of my work utilizes UV, optical, and near infrared spectra from a mixture of space and ground-based observatories.
A key aspect of our current models for how newly formed stars interact with their circumstellar disks relies on a direct magnetic connection between the star and the disk, and these models suggest that these young stars must possess strong, globally organized magnetic fields. I pioneered the measurement of magnetic fields on young, roughly solar-mass stars (the so-called T Tauri stars) in order to test and refine these models.
I am now working to expand these studies to both higher mass young stars (the Herbig Ae/Be stars) as well as to newly formed very low mass objects, including brown dwarfs and very young giant planets.”
What inspired you to pursue research in your field?
“I first looked through a telescope at a friend’s birthday party when I was about 9 years old. I saw Saturn for the first time – not just an image in a book but right there in front of me. I was captivated, and fortunately, my parents bought me my own telescope for my birthday later that year. I fell in love with astronomy and charted my course through school to become an astronomer.
When I entered graduate school, I knew I wanted to actually use telescopes – to go out to dark starry skies and see the stars for myself. I was fortunate enough to find an advisor where I could do that, and his area of work was on studying young stars using time series spectroscopy, and this is how I first became interested in the study of young stars.”
“This is a new capability, and with all new capabilities that get deployed, exciting new science becomes enabled. I am looking forward to being part of the discoveries Mauve will produce.”
Professor Christopher M. Johns-Krull
How does your involvement in Mauve align with your research interests?
“As mentioned above, one of my current interests is to move my work to the study of higher mass young stars – the Herbig Ae/Be stars. Mauve’s sensitivity, broad spectral coverage, and operational mode are well matched to perform studies of the temporal variability of the spectra of Herbig stars, which will provide a new understanding of how these stars are interacting with their surrounding accretion disks and their near stellar environment.”
Could you describe the science theme you are working on with Mauve?
“Studies of the temporal variability of accreting T Tauri stars have played an important role in developing our understanding of these newly formed stars and their interactions with their environment. Because Herbig stars are more massive than T Tauri stars, their internal structure is different, and this is expected to result in much weaker stellar magnetic fields.
If our understanding of the accretion processes in young stars is correct, this will change how accretion occurs onto Herbig stars. This difference is also expected to have a major effect on the ability of these young stars to produce strong outflows. Mauve time series spectroscopy will allow us to explore and test for these differences.”
What aspect of Mauve are you particularly excited for?
“I am excited to get my hands on the data. Mauve will consistently deliver high-quality spectral data with a cadence ideally suited for our studies of young stars. This is a new capability, and with all new capabilities that get deployed, exciting new science becomes enabled. I am looking forward to being part of the discoveries Mauve will produce.”
What synergies do you see between Mauve and other ground-based/space-based telescopes?
“My own interests with Mauve center on time series studies of young stars, which have very natural synergies with satellite missions such as Kepler, K2, and TESS. While these were essentially transiting planet-finding missions, they have made a huge impact in variability studies of all classes of stars, including very young ones.
Mauve will add a spectral component that was missing from these earlier missions that will greatly expand its impact. While Mauve’s spectroscopic capabilities are exciting, it will operate at low spectral resolution, so there are additional synergies with ground-based telescopes that can study accretion and wind-related spectral lines at high spectral resolution that will nicely complement the data that Mauve will obtain.”
How has your experience been working with the Mauve Science Collaboration?
“Working with the Mauve collaboration has been a lot of fun. The folks at Blue Skies Space have been great. It is amazing what they have been able to accomplish. I have also very much enjoyed working with other members of the science team and learning from their projects. In particular, several people are pursuing flare star research.
Flares, of course, are driven by stellar magnetic fields and the young stars I study also show flaring activity because of their strong magnetic fields. Understanding the different sources of variability in young stars, from accretion and wind variability to flaring, is critical, and so I have been very excited to learn from my colleagues with complementary expertise.”