Add to Calendar 2026-02-23T16:00:00 2026-02-23T17:00:00 Astronomy from the Stratosphere with Balloon-borne Telescopes Event Information: Abstract: Stratospheric balloon telescopes offer a near space-quality platform for astrophysical research at a small fraction of the cost of an equivalent satellite telescope. Helium balloons can lift scientific payloads of up to 3500 kg to altitudes of up to 48 km above the Earth’s surface on flights ranging from a few hours to weeks. By operating above more than 99.5% of the atmosphere balloon telescopes can achieve much better sensitivity than ground-based telescopes, particularly in the far-IR, sub-mm and mm regimes of the electromagnetic spectrum.In this talk I will discuss challenges of designing, building and operating stratospheric balloon-borne telescopes.  I will also discuss two different high frequency balloon-borne radio astronomy applications. The first is THz detections of linearly polarized thermal dust emission to trace magnetic fields in star-forming regions with the Balloon-borne Large Aperture Sub-mm Telescope for Polarimetry (BLASTPol).  Data from BLASTPol’s 2012 Antarctic flight have shown that magnetic fields can play an important role in shaping regions of star-formation, and have led to a re-examination of models of interstellar dust.  I will finish by discussing a Queen’s led project to demonstrate that stratospheric balloon telescopes can be used in “Earth-sized” telescopes, such as the Event Horizon Telescope, using the technique of Very Long Baseline Interferometry (VLBI).  We built and launched a pathfinder 22 GHz Balloon-borne VLBI Experiment (BVEX) from Timmins, Ontario in August 2025, though the flight was hindered by a leak in the launch balloon, and we are now preparing for a second BVEX flight from Palmas, Brazil in 2027.  Future mm- and sub-mm VLBI observatories that include balloon-borne telescopes have the potential to advance our understanding of jet launching from supermassive black holes and to improve the current resolution limit in astronomy.  Bio: I am an astrophysicist in the Department of Physics, Engineering Physics and Astronomy at Queen's University. My research focuses on understanding how stars and planets from out of interstellar gas.  I am particularly interested in studying whether the magnetic fields that thread through star-forming regions significantly slow down or halt the gravitational collapse of dense gas. For my research I both use extremely powerful ground-based telescopes (such as the Mopra telescope in Australia, the Atacama Large Millimeter Array (ALMA) in Chile, and the Large Millimeter Telescope in Mexico) and work with international teams of astrophysicists to build stratospheric balloon-borne telescopes.  Balloon-borne telescopes operate above 99.5% of the Earth's atmosphere, allowing us to observe colours of light that would otherwise require a much more expensive space telescope.  Our most recently constructed balloon-borne telescope, BLAST-TNG, measures polarized light from dust grains in order to construct incredibly detailed maps of magnetic fields in star-forming regions.  BLAST-TNG launched in January 2020 launching from McMurdo Station, Antarctica.  My group is also working to demonstrate that balloon telescopes can be used in global arrays of telescopes using a technique called Very Long Baseline Interferometry (VLBI).  We will be launching a pathfinder balloon telescope, the Balloon VLBI Experiment (BVEX), in 2025. I received my PhD from the University of Toronto in 2013, where I worked with Barth Netterfield on building BLASTPol, an extremely sensitive balloon-borne sub-mm polarimeter that mapped magnetic fields in nearby star forming regions.  Since then I have worked as a CIERA/NSERC postdoctoral fellow at Northwestern University in Evanston, IL and as a Jansky postdoctoral fellow at the National Radio Astronomy Observatory in Charlottesville, Virginia.  I have been an assistant professor at Queen's University since September 2019.  Resources: See Laura's faculty webpage at Queen's University here and her Research Group webpage here Watch an introduction to Laura and her research on Youtube here Access Laura's talk: "A BLASTPol Study of Magnetic Fields in Vela C", from the conference: Star Formation, Magnetic Fields, and Diffuse Matter in the Galaxy: A Conference Honoring the Contributions of Richard Crutcher & Carl Heiles, May 23-26, 2016, Madison, WI, USA (website: http://www.astro.wisc.edu/ch16/)  Event Location: HENN 318

Add to Calendar 2026-03-09T16:00:00 2026-03-09T17:00:00 Cosmological constraints from the Dark Energy Survey Event Information: Abstract: The Dark Energy Survey (DES) imaged 1/8 of the full sky 10 times in each of 5 optical/NIR filters over the course of 6 years.  I will describe the survey, and the results of the recently completed primary cosmological analysis using the weak gravitational lensing and clustering measured from  ~150 million galaxies.  These measurements, combined with the Hubble diagram derived from ~1600 DES Type Ia supernovae, and other state-of-the-art optical/NIR surveys, offer the most stringent tests to date of whether the low-redshift universe we see could have evolved from its early state, as observed via the cosmic microwave background, under the baseline “LCDM” cosmological model.  I will describe how advances in methodology, as well as larger surveys, should yield more-stringent tests in the coming few years. Bio: Gary Bernstein’s research is focused on the use of gravitational lensing—the deflection of light by gravity as predicted by general relativity. His current work consists of large astronomical survey projects from space and ground that will use this lensing effect to measure as-yet-unexplained dark matter and dark energy. His past projects have included surveys of the solar system beyond Neptune and construction of one of the first mosaic CCD cameras to be placed on a large telescope, which was used to measure many of the high-redshift supernovae that provided early evidence of the accelerating universe. The recipient of a CAREER Faculty Award from the National Science Foundation, Bernstein received his doctorate from the University of California, Berkeley, and his bachelor’s degree in physics from Princeton University. He taught at the University of Michigan before joining the Penn faculty in 2002. Bernstein is co-creator of the popular Penn physics course Energy, Oil, and Global Warming. Resources: View Gary's University of Pennsylvania faculty page and personal website Read UPenn article "Gary Bernstein Honored for Extraordinary Achievement and Service" Watch his video on the evidence for Dark Matter: Gary Bernstein - The evidence for Dark Matter  Event Location: HENN 318

Add to Calendar 2026-03-16T16:00:00 2026-03-16T17:00:00 A Galactic Exoplanet Census with the Roman Space Telescope Event Information:   Abstract: NASA’s Nancy Grace Roman Space Telescope, with a planned launch in late 2026, will open up unprecedented discovery space in the infrared universe. Combining Hubble-like sensitivity and resolution with a field of view 100 times larger and a sky-mapping speed 1,000 times faster, Roman will conduct panoramic, high-resolution surveys that will transform our understanding of dark energy, exoplanetary systems, galactic structure, the solar system, and star formation — all while producing an enormous data set that will be analyzed for decades to come. One of Roman’s Core Community Surveys is the Roman Galactic Bulge Time Domain Survey (RGBTDS), an ambitious program that will monitor 1.7 square degrees toward the crowded Galactic center with unprecedented precision and cadence. Over 440 days across six observing seasons, Roman will repeatedly image the same stars every 12 minutes, enabling the detection of planetary systems by using microlensing to reveal thousands of cold planets and elusive free-floating worlds, and transits to discover tens of thousands of hot and warm planets, including Earth-sized and larger worlds orbiting their stars. Together, these observations will deliver the first comprehensive galactic census of exoplanets, spanning all major stellar populations and probing planets with radii or masses above ~2× Earth’s at all separations, from hot Jupiters to icy wanderers beyond the snow line. I will highlight Roman’s revolutionary capabilities, preview its expected scientific yield, and describe the efforts of the Roman Galactic Exoplanet Survey Project Infrastructure Team (RGES-PIT), which is developing the framework, tools, and strategies to maximize the scientific return from the RGBTDS.  Bio: A member of the faculty since 2006, Prof. Gaudi is a leader in the discovery and statistical characterization of extrasolar planets using a variety of methods, including transits and gravitational microlensing. In 2008, he and his collaborators announced the discovery of the first Jupiter/Saturn analog. Prof Gaudi is deeply immersed in analytic and numerical techniques for assessing the yield, biases, and discovery potential of current and next-generation surveys to determine the demographics of exoplanets. More broadly, his interests revolve around the information content of large datasets. Prof. Gaudi is a member of the Science Definition Team for NASA’s Wide-Field Infrared Survey Telescope (WFIRST), and is the chair-elect for the NASA Exoplanet Exploration Analysis Group. Widely recognized within the community for his work, Prof. Gaudi was the 2009 recipient of the Helen B. Warner Prize of the American Astronomical Society, received NSF CAREER and PECASE awards, was named a University Distinguished Scholar in 2016, and in 2017 he was awarded the NASA Outstanding Public Leadership Medal in recognition of his "outstanding leadership as the ExoPlanet Program Analysis Group Chairperson having significant impact on NASA's search for exoplanets and life in the universe." Learn More: View his webpage from Ohio State here: https://www.astronomy.ohio-state.edu/gaudi.1/index.html About the Nancy Grace Roman Space Telescope: https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telescope About the Roman Galactic Bulge Time Domain Survey (RGBTDS): https://science.nasa.gov/mission/roman-space-telescope/galactic-bulge-time-domain-survey/ About Prof. Gaudi's areas of expertise: Extrasolar planets: https://science.nasa.gov/exoplanets/ About Starlight suppression technology: https://science.nasa.gov/astrophysics/programs/exep/technology/starshade/ About Astrobiology: https://astrobiology.nasa.gov/  Event Location: HENN 318

Add to Calendar 2026-03-23T16:00:00 2026-03-26T17:00:00 ASTRO Colloquium with Alex Pope Event Information: This page will be updated with the speaker's information, presentation abstract and resource links, soon! Event Location: HENN 318