Star Talk: The quest for 1% – the past, present and future for measuring the Hubble Constant and the expansion of the Universe

star_talk_oct “The quest for 1%: the past, present and future for measuring the Hubble Constant and the expansion of the Universe”, presented by Professor Hilding Neilson

Abstract: Almost a century ago, Edwin Hubble discovered that galaxies appear to be moving away from us and that farther galaxies moved at faster rates. This discovery revolutionized our view of the Universe and started the field of modern cosmology. Ever since, astronomers have been trying to better measure the expansion of the Universe, the Hubble constant, using numerous standard candles. In this talk, Professor Neilson will talk about the rich history of measuring the Hubble constant from some of the great arguments to the paradigm shift initiated by the results of the Hubble Space Telescope Key Project. He will conclude by discussing the future for measuring the Hubble constant to 1% precision to shed new insights into the dark matter and dark energy content of the Universe.

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Star Talk: Variable Stars – Action in the Sky

var_stars “Variable Stars: Action in the Sky”, presented by John Percy, Professor Emeritus of the Department of Astronomy & Astrophysics, and Dunlap Institute

Abstract: Stars aren’t changeless and boring. They may eclipse, pulsate (vibrate), flare, erupt, or even explode. These processes cause the stars to vary in brightness over time and, by studying these variations, we can learn about the nature, evolution, birth and death of the stars, and about the physical processes that occur within them. Variable stars help us to understand some of the most exciting and bizarre objects in the sky: exoplanets, supernovas, pulsars, quasars, gamma-ray bursts, and even black holes. I will also explain some of the ways in which Canadian astronomers, and skilled amateur astronomers, and my undergraduate research students are contributing to this research.

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Star Talk: Planets Around Expired Stars

star_talk_sep “Planets Around Expired Stars”, presented by Professor Yanqin Wu

Abstract: Professor Yanqin Wu investigates the formation and evolution of planets, both inside and outside our own Solar System. Her current attention is devoted to a recently discovered puzzle, the presence of planetary systems around white dwarf stars, stars that have lived through their lives and are cooling off quietly in their cemeteries. The observational evidences are difficult to square with our current knowledge about the extra-solar planetary systems, and perhaps a new picture is required.

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Star Talk: Exploring the Ghostly Side of Galaxies with Dragonfly

star_talk_dragonfly“Exploring the Ghostly Side of Galaxies with Dragonfly”, presented by Dr. Roberto Abraham

Abstract: Bigger telescopes are usually better telescopes…. but not always. In this talk I will explore the ghostly world of large low surface brightness structures, such as galactic stellar halos, low-surface brightness dwarf galaxies, and other exotica such as supernova light echoes. These objects are nearly undetectable with conventional telescopes, but their properties may hold the key to understanding how galaxies assemble. I will describe why finding these objects is important, and why it is so devilishly difficult.

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Star Talk: The World Records of the Universe


“The World Records of the Universe”, presented by Dr. Bryan Gaensler

Abstract: We all love it when a world record is broken. But the records set here on Earth are puny and pathetic compared to those set elsewhere in our vast cosmos. What’s the coldest place in space? What’s the fastest object in the Universe? What’s the biggest object we’ve ever seen in space, and the smallest? How weak and how strong does gravity get? Join astronomer Bryan Gaensler for a tour of the extremes of our amazing Universe.

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