University of Toronto Astronomy Colloquia



	ASTRONOMY COLLOQUIA

Fall 2011

Sep 16

Dr. Sijime-Jan Paardekooper (University of Cambridge)
Migration of rocks, planets and hurricanes in protoplanetary discs
Planets form in discs of gas and dust around young stars. Since the discovery of the first extrasolar planet around a solar type star, a gas giant planet on an orbit of just a few days, it has become apparent that orbital migration should play a major role during planet formation. While planet migration is able to explain this new class of planets, the Hot Jupiters, theoretical migration rates were alarmingly fast, essentially predicting that *all* gas giant planets should be Hot Jupiters. I will discuss the latest insights in planet migration,and show that recent progress allows for slower migration rates. At the same time, new types of migration keep showing up, indicating that all planetary building blocks, from the very small to the very large, are very mobile inside protoplanetary discs.

Sep 23

Dr. Jason Kalirai (Space Telescope Science Institute)
A Deep, Wide-Field, Panchromatic Survey of 47 Tuc and the SMC
Nearby resolved stellar populations such as Galactic star clusters anchor our understanding of the Universe. Clusters are ideal testbeds to advance our knowledge of stellar evolution and structure, and provide a calibration of astrophysical relations that aim to interpret light across the Universe. Yet, over the past century of work, most of this effort has focused on visible light investigations given the lack of a high-resolution, sensitive, and wide-field infrared facility. This talk will highlight the first results from a new HST imaging survey of the best studied globular star cluster in the sky, 47 Tuc. The survey strategy uses 121 orbits with the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) and both the UVIS and IR channels of the newly installed Wide Field Camera 3 (WFC3) instrument. The full analysis of the data set reveals unprecedented panchromatic color-magnitude diagrams exhibiting complete stellar sequences that extend from the hydrogen burning limit, up to the brightest giants, and down to the coolest remnants in the cluster. These observations will enable a new level of calibration for fundamental astrophysical relations. The talk will also describe the unchartered discovery space that JWST will explore through ultra-deep IR imaging and MOS spectroscopy of nearby resolved stellar populations.

Last modified: 07 Sep 2011, 11:33:50

Mike Reid (mreid@astro) / Bob Abraham (abraham@astro) / Mariangela Bonavita (bonavita@astro)

Colloquia are Fridays, at 2 PM, in Cody Hall. They are followed by refreshments in the lounge, AB 201.

Instructions for speakers

Schedule with abstracts

Schedule without abstracts

Student seminars

Physics colloquia

Past colloquia: 2003A, 2003B, 2004A, 2004B, 2005A, 2005B, 2006A, 2006B, 2007A, 2007B, 2008A, 2008B, 2009A, 2009B, 2010A, 2010B, 2011A

Current colloquia: 2011B