Ohio State nav bar

Astronomy Colloquium

OSU Astronomy Colloquium (Image Source: NASA)
November 17, 2017
3:00PM - 4:00PM
1080 Physics Research Building

Date Range
Add to Calendar 2017-11-17 15:00:00 2017-11-17 16:00:00 Astronomy Colloquium Planets around A-stars as Anchors for Planet Migration George Zhou - HarvardVery few planets have been confirmed around early type main sequence stars, since these are often too rapidly rotating for precise radial velocities to be obtained. Of the ~1900 transiting planets known today, only six have been confirmed to transit stars hotter than T>7000K. However, planets around high mass stars are key pieces of the planet formation puzzle, they are important to understanding giant planet formation and migration. For example, the protoplanetary disk mass around A-type stars should be significantly higher than that around solar-type stars, leading to a higher planet occurrence rate, and dynamically hotter systems. The stellar multiplicity rate is also higher for higher mass stars. Will the dynamically hotter environment around A-type planet-hosting stars result in different hot-Jupiter migrational pathways than around solar-type stars? We are using the Doppler tomography technique to confirm and characterise these planets around A-stars. I will detail our recent discoveries with the K2, KELT, and HAT surveys, and describe the next steps in defining the planet migration pathways that lead to these hot-Jupiters in the context of TESS. Coffee and Donuts served at 2:30pm in 4054 McPherson Lab.  1080 Physics Research Building Department of Astronomy astronomy@osu.edu America/New_York public

Planets around A-stars as Anchors for Planet Migration 

George Zhou - Harvard

Very few planets have been confirmed around early type main sequence stars, since these are often too rapidly rotating for precise radial velocities to be obtained. Of the ~1900 transiting planets known today, only six have been confirmed to transit stars hotter than T>7000K. However, planets around high mass stars are key pieces of the planet formation puzzle, they are important to understanding giant planet formation and migration. For example, the protoplanetary disk mass around A-type stars should be significantly higher than that around solar-type stars, leading to a higher planet occurrence rate, and dynamically hotter systems. The stellar multiplicity rate is also higher for higher mass stars. Will the dynamically hotter environment around A-type planet-hosting stars result in different hot-Jupiter migrational pathways than around solar-type stars? We are using the Doppler tomography technique to confirm and characterise these planets around A-stars. I will detail our recent discoveries with the K2, KELT, and HAT surveys, and describe the next steps in defining the planet migration pathways that lead to these hot-Jupiters in the context of TESS. 

Coffee and Donuts served at 2:30pm in 4054 McPherson Lab.