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Abstract
Exoplanets are the planets that orbit stars other than the Sun. As of today, roughly 4900 exoplanets have been discovered in our Milky Way galaxy alone. NASA’s statistics state that each of the 300 billion stars in our galaxy has at least one planet orbiting it. This mind-blowing study compels us to ask one of the most famous questions: Are we alone in the Universe? The exoplanet discoveries made so far are already helping us to understand how planets form and evolve and what the atmospheres of exo-worlds look like, however, finding signs of life outside of Earth is still an unachievable feat.
One way to search for life elsewhere from Earth requires big telescopes (30-meters+), which need to be equipped with exoplanet finding instruments. One of the techniques that I work with is called direct imaging, which translates into taking family portraits of extra-solar systems using the current big telescopes (8-10-meters). Exoplanets are roughly thousand to ten billion times fainter than their stars and finding such a dim signal in the presence of an overwhelmingly bright star is technically challenging. Moreover, the light of a star-planet pair that traverses through the Earth is affected by atmospheric layers of different temperatures, humidity and wind speeds which blurs out the signal captured by scientific cameras. The huge structure of telescopes also vibrates due to the motor’s motion and local wind, which collectively, makes it impossible to separate out signals from exoplanets. This makes direct imaging biased towards finding exoplanets that shine their own light and reside far away (farther than Sun-Saturn distance) from their parent stars. The first and foremost requirement for capturing signs of life is to find closer-in exoplanets by overcoming the technical challenges faced by state-of-the-art direct imaging instruments.
In this talk, I will introduce two main technologies: Adaptive Optics, the art of reshaping the star-planet light and Coronagraphy: the art of blocking the starlight, which we direct imagers use to address the above-stated challenges.
Bio
Garima Singh is a postdoctoral fellow at HAA. She is specialized in developing instruments that take direct images of exoplanets. She completed her Ph.D. in 2015 in collaboration between Subaru Telescope in Hawaii and Paris Observatory in France. Before moving to Canada, a year ago, she worked as a postdoctoral fellow with NASA’s Jet Propulsion Laboratory and Paris Observatory where she continued improving the wavefront sensing capabilities of exoplanet imaging instruments.
Read more on Garima Singh's work on her website.