Exoplanets

Seminar Date:

Friday, May 23rd, 2014
3:15-4:15, Large Conference Room

Speaker:
Dr. Nick Cowan
CIERA - Northwestern University

Title:
Planetary Science from the Top-Down: the Exoplanet Opportunity

Abstract:
What started as a trickle in the mid 1990's is now a torrent, with over one thousand extrasolar planets currently known, and thousands of candidates awaiting confirmation. The study of exoplanets has already revolutionized our view of planet formation, and will soon do the same to our understanding of planetary atmospheres and interiors.  The diversity of exoplanets gives us the leverage to crack hard problems in planetary science: cloud formation, atmospheric circulation, plate tectonics, etc.  However, the characterization of exoplanets presents a challenge familiar to astronomers: our targets are so distant that we only see them as unresolved dots.  I will describe how we can extract spatially-resolved snapshots of planets from such observations. These data are sufficient to constrain low-order climate models and therefore give us insight into the effects of clouds, heat transport, and geochemical cycling. Coarse measurements for a large number of planets is the perfect complement to the detailed measurements possible in the Solar System.  That is the exoplanet opportunity.

Orbits and Atmospheres of Directly Imaged Exoplanets

Seminar Date:

Wednesday, March 12, 2014

Speaker:
Dr. Quinn Kanopacky
Dunlap Institute, Toronto 

Title:
Orbits and Atmospheres of Directly Imaged Exoplanets

The first image of an extrasolar planetary system was obtained in 2008. Since then, there have been nearly a dozen gas giant planets directly imaged. These directly imaged exoplanets offer a new window into the rapidly evolving field of planet formation and evolution.  The ability to separate the light of the planet from its host star is extremely advantageous for studying Jovian planetary atmospheres.  The wide projected separations (~15 to 100 AU) of these planets provide insight into the orbital dynamics of long period objects.  The combination of dynamical and atmospheric characterization can give clues about how these objects form and evolve.  To demonstrate this new insight, I will discuss our team's results from an ongoing monitoring campaign of the HR 8799 directly imaged multi-planet system using the Keck Observatory adaptive optics system.  High precision astrometry has provided constraints on the orbital properties of the four HR8799 planets.  Moderate resolution spectroscopy has given precise estimates of the planets' effective temperature, surface gravity, and composition, leading to tantalizing clues about their formation.  I will also discuss the successful first light runs of the Gemini Planet Imager (GPI), and instrument designed specifically to image and characterize young, widely separated Jovian planets.  I will highlight some early results with GPI and describe the upcoming GPI Exoplanet Survey (GPIES), a three year campaign that will revolutionize our understanding of this fascinating planet population.

To Build an Elliptical Galaxy

Seminar Date:

Monday, Jan 20th, 2014 

Speaker:
Dr. Jenny Greene
Princeton University

Title:
To Build an Elliptical Galaxy

I discuss two essential aspects of elliptical galaxy formation: how they get their stars, and how they lose their gas. For the former, I use integral-field observations of local massive galaxies to study the stellar populations and kinematics of stars at large radius, to understand the origin of the size growth of elliptical galaxies. 

Then I focus on black hole feedback as a means of clearing gas from massive galaxies. I show that luminous obscured quasars have ubiquitous, round ionized outflows with very high gas dispersions of nearly 1000 km/s out to 20 kpc. 

Finally, if time permits I will combine these two themes and present our recent search for sub-pc supermassive black hole binaries. 

Monsters in the Mid-Plane: Galactic Accelerators in the Gamma-Ray Sky

Seminar Date:
November 7th, 2013 
from 3:30-4:30 in the LCR
(Note the special date and time)

Speaker:
Dr. Jack Hewitt
NASA Goddard

Title:
Monsters of the Mid-plane: Galactic Accelerators in the Gamma-Ray Sky

Critical Gameplay

Special Seminar Date:
Friday, October 4th, 2013 
Special Seminar Time:
4pm. 

Speaker:
Lindsay Grace
American University School of Communication

Title:
Alternative Play & Critical Gameplay

Abstract:
Dr. Grace will provide an overview of games as well as the movement toward alternative play and Critical Gameplay. For more details, visit his website or watch his recent presentation at Games for Change.

A Long Time Ago in Galaxies Far, Far Away

Seminar Date:
Wednesday, September 4th, 2013

Speaker:
Dr. Amanda Bauer
Super Science Fellow at the Australian Astronomical Observatory
Sydney, Australia.

Title:
A Long Time Ago in Galaxies Far, Far Away

Abstract:
Galaxies found in the distant, early universe look and behave differently from those in our local universe.  In this talk, I investigate the build up of stars in galaxies over time, which depends strongly on the galaxies and the neighborhoods in which they live. 

Science & Integrated Strategies at the Museum of Science and Industry

Seminar Date:
September 25th, 2013

Speaker:
Dr. Rabiah Mayas
Director of Science and Integrated Strategies,
Museum of Science and Industry

[Addendum: Click here for Dr. Mayas' slides from her seminar talk.]

Title:
Your Title is What?? Science and Integrated Strategies at MSI

Abstract:
Since the formation of the Center for the Advancement of Science Education at MSI several years ago, there have been several organizational changes designed to more strategically and effectively advance the Museum's mission and vision. Among these was the formation of the Science and Integrated Strategies department in 2010, which absorbed a number of existing initiatives and was charged with developing several new ones. 

In total, the department focuses on five primary areas: public programming, engineering and innovation education, evaluation and research, STEM professionals engagement, and interdisciplinary science learning.  The department's initiatives are almost exclusively collaborative (internally and externally), experimental and exploratory, and connected directly to scientific research and practice.  

This talk will highlight the the programs, initiatives, and studies currently underway, the Museum context within which they sit at MSI, and plans for the future, including possible opportunities for partnerships with Adler and other science centers.

Star Formation & Protoplanetary Disks

Seminar Date:
Wednesday, October 2nd

Speaker:
Dr. Neal Evans
Centennial Professor in Astronomy
The University of Texas at Austin

Title:
Low Mass Star Formation

Abstract:
I will review recent progress in understanding the formation
of individual low mass stars and their planetary systems.  In
particular, I'll focus on recent results from Spitzer and Herschel.

Disk-Driven Migration in Hot Jupiters

Seminar Date:
Wednesday, October 16th, 2013

Speaker:
Dr. Konstantin Batygin
Institute for Theory and Computation
Harvard - Smithsonian Center for Astrophysics

Title:
Disk-Driven Migration in Hot Jupiters

Abstract:
The existence of gaseous giant planets whose orbits lie in close proximity to their host stars (“hot Jupiters") can naturally be accounted for by protoplanety disk-driven (type-II) migration, associated with viscous evolution of the nebulae. Recently, observations of this effect during planetary transits have revealed that a considerable fraction of detected hot Jupiters reside on orbits that are misaligned with respect to the spin-axes of their host stars. This observational fact has cast significant doubts on the importance of disk-driven migration as a mechanism for production of hot Jupiters, thereby reestablishing the origins of close-in planetary orbits as an open question. Here we show that spin-orbit misalignment is a natural consequence of disk-driven migration. 

Collisions in the Early Solar System

Seminar Date:
November 13th, 2013

Speaker:
Dr. Fred Ciesla
Geoscience Faculty,
University of Chicago

Title:
Collisions in the Early Solar System

Abstract:
Meteorites provide us with important clues about the conditions present and processes that occurred during the birth of our Solar System.  Deciphering these clues, however, requires a detailed understanding of how the meteorites would have been shaped by the various events known to have occurred during these stages of evolution.  I will discuss recent work we have carried out to understand the roles that collisions among meteorite parent bodies would have played in shaping the specimens in our collections, and how this could relate to understanding of planet formation in general.

Cultural Heritage Experiences through Socio-personal interactions and Storytelling

Seminar Date:
July 2nd at 2-3pm (note the different time!)

Speaker:
Dr. Maria Roussou
Virtual Reality Designer and Researcher

Title:
The CHESS Project [Cultural Heritage Experiences through Socio-personal interactions and Storytelling]

Abstract:
Cultural heritage institutions nowadays face the important challenge of making their collections more engaging to visitors, especially the young ‘digital natives’, while exploiting, in new forms of cultural interactive experiences, the recently developed digital libraries. An approach for cultural heritage institutions (e.g. museums) would be to capitalize on the pervasive use of interactive digital content and systems in order to offer experiences that connect to their visitors’ interests, needs, dreams, familiar faces or places; in other words, to the personal narratives they carry with them and, implicitly or explicitly, build when visiting a cultural site.

Investigations of Lava Flows on Earth and Mars

Seminar Date:
July 24, 2013

Speaker:
Dr. David Crown
Senior Scientist,
Planetary Science Institute

Title:
The Geologic Histories of Mars, Venus, and Io

Abstract:
The Tharsis volcanic province on Mars contains vast lava plains surrounding the largest shield volcanoes in the solar system. Current research examines the styles and sequences of volcanism in southern Tharsis using imaging, topographic, and compositional datasets acquired by recent spacecraft missions. This work combines traditional geologic mapping with detailed flow field mapping to document observations important for interpreting volcanic processes and geologic history. The morphology of lava flow lobes reveals the nature of flow emplacement processes and is used to assess flow field development and stratigraphy. Populations of small, superposed impact craters are used to derive relative and absolute age constraints for individual flows and flow sequences.

Accurate interpretations of volcanic processes on other planets are dependent upon field and remote sensing analyses of terrestrial analogues. New capabilities for field analyses of active lava flow emplacement are being utilized to qualitatively and quantitatively characterize lava flows in order to directly link surface morphology to observed emplacement processes, providing a robust foundation for interpretations of planetary volcanic features. A combination of ground-based scanning LiDAR, thermal imaging, and high-definition video and time-lapse photography provide rapid acquisition of high-resolution spatial and high-precision thermal datasets for advancing tube-fed pahoehoe flows in Hawaii. High-definition video and time-lapse photography document the nature and changes in flow behavior and are used for interpretation and analysis of thermal and topographic data. The thermal data show the distribution of lava surface temperatures and are used to identify new lava breakouts and to define and chart the evolution of discrete lava units. Repeat LiDAR scans at regular intervals during flow emplacement are used to document morphometric characteristics of individual flow elements and compound lobes, directly link quantitative morphometric measurements to flow characteristics such as flow morphology and temperature, and calculate flow volumes and advance rates.

Greek Letter Stars at Milli-arcsecond Resolution

Seminar Date:
June 26, 2013

Speaker:
Dr. Bob Zavala
Astronomer,
U.S. Naval Observatory, 
Flagstaff Station

Title:
Greek Letter Stars at Milli-arcsecond Resolution

Abstract:
The brilliant colors of the double star Albireo are often shown to students in introductory astronomy courses. The color differences elicit a "Wow" from the viewer, and this is usually followed by an explanation of colors and temperatures of stars. I'll attempt to re-create some of the "Wow" feeling as I present results of bright Greek letter stars (and one without a Greek letter) resolved on milli-arcsecond scales. Most observations were obtained with the Navy Precision Optical Interferometer (NPOI), a 6-element optical interferometer located in Flagstaff, AZ.

The NPOI resolves close stellar systems and our visual orbits are often combined with other datasets to provide a fairly detailed picture of the components. I'll show results on systems such as a massive O star binary, evolved mass-transferring systems and radio stars. I'll also present radio VLBI observations on similar spatial scales and show how they complement the astrophysical understanding of the sources. I will also discuss how our narrow-angle astrometry supports the Naval Observatory's bright star catalogs.

Star Formation and Jet Interactions near Sgr A*

Seminar Date:
May 13th, 2013

Speaker:
Dr. Farhad Yusef-Zadeh
Faculty
Northwestern University

Title:
Star Formation and Jet Interactions near Sgr A*

Abstract:
There are several sources of interest in the unique region of the Galaxy surrounding Sgr A*. I will focus on two topics related to the supermassive black hole Sgr A* which lies at the dynamical center of the Galaxy. One relates to a three earth mass gas cloud called G2 which is on a collision course with Sgr~A*. We consider the possibility that the gas cloud G2 approaching Sgr A* may encounter a relativistic jet-driven outflow. We present the light curves of Sgr A* at X-ray and radio wavelengths during which G2/Sgr A* interact with each other. I will argue that the origin of how young stellar disks are formed in the context of the passage of a giant molecular cloud interacting with Sgr A*. I will also present ALMA measurements supporting on-going star formation near Sgr A*.

Kepler: Behind Every Planet is a Star

Seminar Date:
March 22nd, 2013

Speaker:
Dr. Lucianne Walkowicz
Henry Russell Norris Fellow
Princeton University

Title:
Kepler: Behind every planet is a star.

NASA: Science with Hubble, JWST, and other NASA Astrophysics Missions

Seminar Date:
February 25th, 2013

Speaker:
Dr. Amber Straughn
Astronomer & EPO Specialist
NASA Goddard

Title:
NASA: Science with Hubble, JWST, and other NASA Astrophysics Missions

Abstract:
In 2009, the complete refurbishment of Hubble gave new life to the telescope, equipping it with powerful new instruments and capabilities. Dr. Straughn will discuss some of the recent highlights from the Wide Field Camera 3 ranging from star formation in nearby galaxies to the most distant galaxy candidates discovered. Hubble has proven to be an outstanding success not only in astronomers' eyes, but also in the public, setting the stage for exciting E/PO and Communications programs in all of NASA's Astrophysics missions. Straughn will outline some of the ongoing and future work NASA is doing with JWST and also within the Astrophysics Science Division at Goddard.

Vampire Stars and the (Re)Birth of Blue Stragglers

Seminar Date:
October 25th, 2012

Speaker:
Dr. Aaron Geller
Lindheimer Fellow
Northwestern University

Title:
Vampire Stars and the (Re)Birth of Blue Stragglers

Abstract:
Blue stragglers are stars that somehow maintain a "youthful", bright and blue appearance while their counterparts of similar mass grow old and die.  Current formation hypotheses for blue stragglers include mass transfer in binaries, mergers of binaries, and stellar collisions.  The origins of blue stragglers tie together many fundamental areas of stellar astrophysics.  Therefore blue stragglers are ideal test subjects to verify the accuracy of binary evolution models and star cluster simulations.  However despite the more than 50 years of research on blue stragglers, their dominant formation mechanism(s) remains a matter of debate, in part due to a lack of direct observational evidence that can distinguish between the formation channels.  In this talk, I will present our detailed observations coupled with N-body numerical models of the blue stragglers in the old open cluster NGC 188. Our results point to a blue straggler origin in "stellar vampirism".  

This research also offers fantastic opportunities for visualizations. The detailed theoretical models and simulations are both educational and visually engaging (and well suited for Planetarium shows!).  I will present a sample of the visualizations that I have developed and used to educate students and the public about blue stragglers, binary stars, stellar evolution and the dynamical evolution of star clusters.

The E-Nova Project: A Multi-Wavelength Initiative to Probe the Ejecta and Environments of Novae

Seminar Date: 
September 27, 2012

Speaker:
Dr. Tommy Nelson
University of Minnesota

Title:
The E-Nova Project: A Multi-Wavelength Initiative to Probe the Ejecta and Environments of Novae

Abstract: 
Novae are the most common stellar explosions in the universe, and an important stage in the evolution of some Type Ia supernova progenitors.  However, important questions remain unanswered about the accretion-ejection cycle in these objects, and the long-term evolution of their white dwarf components.  I will discuss the E-Nova Project, a new observational program designed to probe the ejecta and environmental properties of a diverse sample of novae using a combination of radio, X-ray and optical data. I will focus on some recent results, including an extensive multiwavelength study of the recurrent nova T Pyx, and ongoing observations of two new novae that were unexpectedly detected in GeV gamma rays by the Fermi LAT.