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The Dynamics of the Local Group: Challenges to Convention in the Era of Precision Astrometry

Event Details

Event Dates: 

Monday, December 5, 2016 - 4:00pm

Seminar Location: 

  • JILA Auditorium

Speaker Name(s): 

Gurtina Besla

Speaker Affiliation(s): 

University of Arizona
Seminar Type/Subject

Scientific Seminar Type: 

  • Astrophysical & Planetary Sciences Seminar

Event Details & Abstract: 

Our understanding of the dynamics of our Local Group of galaxies has changed dramatically over the past few years owing to significant advancements in astrometry and our theoretical understanding of galaxy structure. I will provide an overview of key contributions by the Hubble Space Telescope to this evolving picture. In particular, I will highlight the HSTPROMO team’s proper motion measurements of key players in the Local Group, such as the most massive satellites of the Milky Way (the Large and Small Magellanic Clouds), the first ever direct proper motion measurement of M31 and an implied new orbital history for M33. These results have met with controversy, challenging preconceived notions of the orbital dynamics of key components of the Local Group. I will further highlight the importance of HST’s continued role in this field in the era of Gaia.