Skip to Local Navigation
Skip to Content
California State University, Long Beach
Print this pageAdd this page to your favoritesSelect a font sizeSelect a small fontSelect a medium fontSelect a large font
Department News and Colloquium

Physics & Astronomy Colloquium at CSU Long Beach

Physics Colloquium

Constraining Planet Formation

with Directly Imaged Exoplanets

Prof. Quinn Konopacky

University of California San Diego

September 18, 2017
Time: 11:00 am
Refreshments will be served at 10:45 am in HSCI-224.

In the past decade, several new jovian exoplanets at wide separations have been revealed using ground based telescopes equipped with adaptive optics systems. These planets, with masses between ~2-14 MJup, remain a puzzle for both major planet formation models – core accretion and gravitational instability. At the same time, they offer a powerful tool in the hunt for observational constraints of formation, as they can be characterized with both imaging and spectroscopy. I will describe our recent efforts to push beyond the discovery phase into the realm of detailed characterization of these planetary systems. Using the Keck adaptive optics instrument suite, we have been targeting the HR 8799 multiplanet system. Astrometric monitoring with imaging over the course of a decade has allowed for orbital constraints in HR 8799 based on a self-consistent data set. This has allowed us to minimize systematic uncertainties and determine that the planets are likely co-planar and have low eccentricities. Spectroscopic observations of HR 8799b and c have yielded the best-ever spectra for any exoplanet. Using these observations, we have measured the C/O ratio in these planets, which can be used as a diagnostic of formation. Finally, I will discuss a new discovery with the Gemini Planet Imager of a substellar companion to a debris disk host star, HR 2562. This object seems to have the mass of a brown dwarf (~30 MJup), but orbits within a cleared inner hole in the debris disk. Future observations of the planet and disk could point to evidence of a “planet-like” formation process for this companion in spite of its high mass.

All Physics students & faculty should attend!

See the colloquium schedule and its archive of previous talks

Colloquia are scheduled to start Mondays at 11:15am sharp in Peterson Hall 1, Room PH1-223. Refreshments are served from 10:45am to 11:05am in Room HSCI-224 (next to the department office) and everyone is invited to mingle with faculty and students!


For information and suggestions about the colloquium please contact the colloquium coordinator:
Prof. Prashanth Jaikumar, Phone: 562-985-5592, Email:

Directions to Campus

  • Access to Campus
  • Campus Maps
  • Parking on campus: contact the coordinator of the colloquium. If not reachable, call the department office (562) 985-7925. If none of these are available at the time you need information, call (562) 985-4146 or go to the drive-through information booth at the main campus entrance (on Beach Drive, near the crossing to Bellflower).
  • Walk (or ask for a ride on an on-campus shuttle) to the department office: Hall of Sciences, Room 220 (HSCI-220). The coordinator will provide the necessary informations.
  • Any question or problem: call the colloquium coordinator or the department office (562) 985-7925.

Colloquia Sponsors:

We acknowledge with gratitude donations and support from the following present sponsors:

  • H.E. and H.B. Miller and Family Endowment
  • Benjamin Carter
  • The American Physical Society
  • Anonymous

We also acknowledge with gratitude our past donors: The Forty-Niner Shops, Inc., The Northrop Grumman Foundation, Sandra Dana, Anonymous.

If you wish to support the Colloquium, please contact the colloquium coordinator or the department chair. Thank you!

Colloquia Schedule

Academic Year 2017-2018

Date Title Speaker and Affiliation
September 11 Physics Department Meet and Mix Faculty and Staff,
California State University, Long Beach
September 18 Constraining Planet Formation with Directly Imaged Exoplanets Prof. Quinn Konopacky,
University of California, San Diego