CfA SSP Seminar<br><a href="http://cfa-www.harvard.edu/events/calendar/latest.html">http://cfa-www.harvard.edu/events/calendar/latest.html</a><br><br><br>DATE: MONDAY, September 24<br>TIME: 12:00<br>ROOM: Pratt Conference Room, 60 Garden St.
<br>SPEAKER: Ruth Murray-Clay (U.C. Berkeley)<br><br>"Three Problems in Planet Formation: The Kuiper Belt, Hot Jupiters, and<br>Transitional Disks"<br><br>Abstract<br><br>The past 15 years have produced a plethora of observations that address
<br>the question of how planetary systems form. I will discuss clues to<br>planet formation in three settings:<br><br>(1) Nearly a quarter of the ~500 Kuiper belt objects with securely<br>determined orbits are in mean-motion resonance with Neptune. The planet
<br>likely captured these KBOs as it scattered planetesimals and migrated<br>outward. Does the noise inherent in migration driven by discrete<br>scattering events interfere with a planet's ability to capture bodies<br>
into resonance?<br><br>(2) About 1 in 5 of the ~200 extrasolar planets discovered to date are<br>hot Jupiters, which likely migrated from their birthplaces to distances<br>less than 0.05 AU from their host stars. Photoionization heating from
<br>UV radiation incident on the atmospheres of hot Jupiters drives<br>planetary mass loss in the form of hydrodynamic winds. What are the<br>properties of these winds, and how much mass will a hot Jupiter lose<br>over its lifetime?
<br><br>(3) Approximately 10% of the disks around young stars have inner holes<br>but are still accreting. These transitional disks are likely in the<br>process of dissipating. What drives disk accretion in these systems?
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