A Trip inside the Desert: Understanding Some of the Most Extreme Worlds in the Galaxy

by Prof. James Jenkins (Universidad Diego Portales)

Thursday 18 Jan 2024, 10:00 → 11:00 Asia/Shanghai

TDLI Meeting Room N601 (East Wing of Floor 6, North Building)

Abstract

In this talk I will discuss our efforts to better understand the nature 

of the Neptunian Desert, one of the features most prominent in the 

radius-period-mass diagram for exoplanets.  Large-scale transit surveys, 

coupled with follow-up radial-velocity measurements, have revealed a 

large population of hot, rocky super-Earths orbiting very close to their 

host stars (orbital periods < 4 days), adding to the already known 

population of hot Jupiters.  However, it quickly became apparent that 

there exists very few Neptunes at the same orbital periods, giving rise 

to the Neptune Desert.  Models that incorporate photoevaporation and 

planet migration can mostly explain this feature, yet other processes 

may be at play, particularly for those with the shortest orbital 

periods, Roche Lobe Overflow or Tidal Disruption for example.  I will 

explain our efforts to discover new hot Neptunes located in the Desert, 

and our follow-up programs to understand their atmospheric chemistries 

and physical processes, providing ways to unlock their formation and 

evolution histories.  I will focus mostly on the LTT9779 system, 

arguably the best laboratory we have for studying the atmosphere of a 

Desert Neptune, showcasing results from ground- and space-based 

facilities that we have used to gain a deeper insight into the Neptune 

Desert.

Biography

James Jenkins is a Full Professor at the Institute of Astrophysical 

Studies (IEA), part of the Universidad Diego Portales in Santiago, 

Chile.  After obtaining his Ph.D from the University of Hertfordshire in 

the UK studying extrasolar planets and their host stars, James took up a 

postdoctoral position at Penn State University in the USA, before 

arriving to the Department of Astronomy at the Universidad de Chile in 

2008.  The university then awarded him an Assistant Professorship in the 

department in 2014, becoming the first non-Chilean to hold such a 

position.  He then moved to the IEA in 2021 to take up his current role, 

helping to expand the institute's efforts to search for and characterise 

extrasolar planets.  In his time as a researcher, James has published 

over 180 papers in internationally recognised journals on the subject, 

has been features in numerous national and international press releases 

to describe his results, and is currently a Principal Investigator of 

the largest science project in Chile, CATA.

Chair

Fabo Feng

Division

Astronomy and Astrophysics

Other information

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Meeting ID: 462147259