Eliza Kempton

(formerly: Miller-Ricci)
Assistant Professor of Physics
Grinnell College
Department of Physics
1116 8th Ave.
Grinnell, IA 50112

Eliza Kempton

Office: Noyce Science Building Room 1034 Email: kemptone (at) grinnell (dot) edu Phone: (641) 269-9803

Bio

I’m Eliza Kempton, but I used to be Eliza Miller-Ricci. I am an assistant professor of physics at Grinnell College in Grinnell, Iowa.

I graduated summa cum laude from Middlebury College in 2003 with a B.A. in physics. I received my Ph.D. from Harvard University in 2009 in astronomy. The title of my Ph.D. thesis was “Towards Detecting and Characterizing Earth-like Extrasolar Planets”. After completing my doctoral degree I spent several years as a Sagan postdoctoral fellow at U.C. Santa Cruz.

My research centers on planets orbiting distant stars, known as extrasolar planets or exoplanets for short. I am particularly interested in some of the smallest exoplanets that have been detected so far. These planets, known as super-Earths, are intermediate in size and mass between the rocky and gas giant planets in our solar system, and therefore represent a fundamentally new class of planets for astronomers to study. I perform theoretical calculations of the structure and observable properties of exoplanet atmospheres. I also have an observational program to confirm and characterize transiting exoplanets using the telescope at Grinnell's Grant O. Gale Observatory.

Current Research Students

  • Andrew Baldrige Andrew Baldrige – B.A. Physics 2017 (expected)
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
  • Sunny Zhao Yun (Sunny) Zhao – B.A. Biology 2018 (expected)
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
  • Jisheng Zhang Jisheng Zhang – B.A. Physics 2016.5 (expected)
    Project: Emission Spectra of Hot Jupiters from 3-D General Circulation Models

Former Research Students

  • Rostom Mbarek – B.A. Physics & German 2016
    Project: Clouds in Super-Earth Atmospheres: Chemical Equilibrium Calculations
    Project: Challenges to Recovering the Mass of Super-Earths from their Transmission Spectra
    Current Position: Ph.D. student, University of Chicago (Astronomy) – starting fall 2016
  • Jack Muskopf – B.A. Physics 2016
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
  • Patrick Slough – B.A. Physics 2015
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
    Project: Exoplanet Transmission Spectrum Modeling with Exo-Transmit
    Current Position: Software Developer
  • Bryson Cale – B.A. Physics & Mathematics 2016
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
    Current Position: Masters student, Missouri State University (Astronomy) – starting fall 2016
  • Albert Owusu-Asare – B.A. Physics 2016
    Project: Exoplanet Transmission Spectrum Modeling with Exo-Transmit
  • Julia Sauerhaft – B.A. Physics 2015
    Project: Exoplanet Observations with Grinnell's Grant O. Gale Observatory
  • Roman Grigorii – B.A. Physics 2015
    Project: Opacity Data for Exoplanet Atmosphere Models
    Current Position: Ph.D. student, Northwestern University (Mechanical Engineering)

Overview

  • Over the past two decades the number of known solar systems has gone from one (our own) to thousands. One of the most startling aspects of the discovery of these “exoplanet” systems is that most of them bear no resemblance to our solar system. Among the new classes of planets astronomers have discovered are “super-Earths” – planets with sizes and masses intermediate between Earth’s and Neptune’s – and “hot Jupiters” – massive gas giant planets orbiting their host stars at distances only a few percent of the Earth-Sun distance. In my research, I endeavor to understand these exoplanet systems from both an observational and a theoretical perspective through the study of exoplanet atmospheres and contributions to the detection of new planets.

    Exoplanets
    Exoplanets discovered as of the end of 2014 with well-characterized masses and orbital periods. Regions of the plot corresponding to "super-Earths" and "hot Jupiters" are indicated. The locations of the Earth and Jupiter are shown with blue symbols. Other solar system planets would be located beyond the edges of this plot. Planets discovered by the transit method are shown in red, the radial velocity (or Doppler) method in black, and the microlensing method in green. (Data via www.exoplanet.eu)

Theoretical Work:

  • Much of my research involves developing computational models of the atmospheres of exoplanets, in order to predict and diagnose their atmospheric structure and chemistry. These models are used to to aid in planning of future observations and instruments for exoplanet characterization, and to interpret observations of exoplanet atmospheres.

    My primary research interest is the study of super-Earth atmospheres. While gas giant planets have atmospheres primarily composed of hydrogen and helium, super-Earths can have far more diverse atmospheric composition. I model the observable signatures of super-Earth atmospheres with a goal of understanding the composition, clouds, and temperature structure of this diverse population of planets.

    MMW
    Transmission spectra for super-Earths with hydrogen-rich (blue), intermediate hydrogen content (red), and hydrogen-poor (green) atmospheres. The depth of spectral features depends inversely on the atmospheric mean molecular weight causing the hydrogen-rich atmosphere to have the largest absorption features. (From Miller-Ricci Kempton, Sasselov, & Seager, Astrophys. Journal, 2009.)
    GJ_1214b
    Model transmission spectra for the transiting super-Earth GJ 1214b. Newer data imply this planet must have a high layer of clouds or haze. (From Miller-Ricci Kempton, Zahnle, & Fortney Astrophys. Journal, 2011.)

    I also produce spectral models of hot Jupiters based on 3-D atmospheric circulation calculations. By modeling the emergent light from the planet self-consistently with the 3-D structure and wind velocities of its atmosphere, we can look for the signatures that atmospheric dynamics imprint on the planet’s emission and transmission spectra. My colleague Emily Rauscher and I have found that both dayside-to-nightside winds and planetary rotation can leave observable signatures in hot Jupiter transmission spectra.

    HJ_spectrum
    Doppler shifted transmission spectra of the transiting hot Jupiter HD 209458b. Strong dayside-to-nightside winds imprint a blueshift on the spectrum as it transits in front of its host star. (From Miller-Ricci Kempton & Rauscher, Astrophys. Journal, 2012.)

Observational Work:

  • Using the Grinnell College Gale Observatory telescope – a 24” (0.6-m) Cassegrain reflecting telescope built by DFM engineering – we can observe transiting extrasolar planets under the dark Iowan skies. Grinnell is a part of the KELT-North collaboration to discover new transiting exoplanets in the northern-hemisphere sky. There are many opportunities for Grinnell College undergraduates to be involved in this work. Please contact me if you are interested.

    TrES3
    A transit of the exoplanet TrES-3b observed by Grinnell College undergraduates using the Gale Observatory telescope.
    Gale telescope
    Grinnell College's Grant O. Gale Observatory at night. (Image source: www.grinnell.edu)

Teaching

  • Teaching students about the laws of physics and how they are expressed in the world around us is one of the most rewarding parts of my job. At Grinnell I have taught courses across the physics curriculum from introductory astronomy through upper-level physics theory classes. Previously I taught in the Harvard astronomy department and summer school as a graduate student teaching fellow. I also taught a series of inquiry-based workshops on transiting exoplanets at Hartnell Community College in Salinas, California as a part of the ISEE Professional Development Program (PDP). In the classroom, I work to engage my students in the science of physics and astronomy by confronting them with the realities of our physical world and the Universe as a whole. I have used clicker technology, peer instruction, group problem solving, independent projects, and inquiry-based instruction techniques as ways to involve my students in the active learning process.

Diversity

  • Like many fields, physics and astronomy would benefit from increased representation of individuals from underrepresented backgrounds, to better reflect the composition of the population as a whole. I participate in a number of groups and programs aimed at supporting diversity and equity within the physical sciences. At Grinnell I take part annually in the Grinnell Science Project (GSP) pre-orientation program. GSP is Grinnell’s award-winning effort to increase the number of students from underrepresented groups earning degrees in the sciences. As a part of the program, each year we invite incoming students from backgrounds traditionally underrepresented in the sciences to participate in a one-week pre-orientation before the start of the fall semester. I also co-lead Grinnell's Women in Physics (WIP) group. We meet several times each semester to eat pizza, chat informally, and discuss issues pertaining to the underrepresentation of women in the physical sciences. Please contact me if you would like to be added to the group mailing list.

Courses Taught at Grinnell College

  • PHY 180 – Bridges, Towers, & Skyscrapers – fall 2015
    PHY 234L – Computational Mechanics Lab – spring 2016
    TUT 100 – First-Year Tutorial: Perspectives on Life in the Universe – fall 2014
    PHY 131 – General Physics I with Lab – spring 2013, 2014, 2015, fall 2014, 2015
    PHY 132 – General Physics II with Lab – fall 2012, 2013, spring 2016
    PHY 395 – Stellar & Planetary Astrophysics – spring 2015
    PHY 314 – Thermodynamics and Statistical Physics – spring 2013, 2014, 2016
    PHY 116 – The Universe and Its Structure – fall 2012, 2013

  • June 2016 – Welcome to this summer’s MAP research students!
    This summer we have three students joining the group for Mentored Advanced Projects (MAPs). Andrew Baldrige, Jisheng Zhang, and Sunny Zhao will be spending 10 weeks working on research projects related to transiting exoplanets.

  • June 2016 – Two Kempton group alumni headed to graduate school in astronomy & astrophysics
    Graduation is always bittersweet as we say goodbye to former students. This year two graduating Kempton group MAP students will be continuing their studies in astronomy and astrophysics in graduate school. Rostom Mbarek will pursue his Ph.D. in the Department of Astronomy & Astrophysics at the University of Chicago. Bryson Cale will pursue his masters in astronomy at Missouri State University. We wish them the best of luck!

  • Feb. 2016 – Eliza Kempton wins Cottrell Scholar Award
    Eliza was one of 24 early career academic scientists awarded this year’s Cottrell Scholar Award. The award will provide $100,000 in funds to support Eliza’s research and teaching. Eliza’s Cottrell Scholar research program is entitled “Atmospheric Structure and Emission Spectrum Calculations for Extrasolar Super-Earths: Looking Toward JWST and Beyond.” She will also develop a spatial reasoning course for students with a low level of STEM preparation and a peer mentoring program for STEM students from traditionally underrepresented groups. This was the first year that the Cottrell Scholar award was open to faculty from primarily undergraduate institutions, and Eliza was one of 5 such individuals to be awarded the grant.
    http://rescorp.org/awards-database/awardee/atmospheric-structure-and-emission-spectrum-calculations-for-extrasolar-sup

  • Dec. 2015 – Eliza Kempton awarded Grinnell’s Harris Faculty Fellowship
    Eliza is one of two Grinnell College faculty members awarded this year’s Harris Faculty Fellowship – a 1-year pre-tenure research leave. Eliza will spend the year working on radiative transfer calculations of super-Earth atmospheric structure. She will be housed in the Department of Physics and Astronomy at Iowa State University for the year, and she will also travel to work with collaborators around the country.

  • Feb. 2015 – Eliza Kempton wins Cottrell College Science Award
    Eliza is a recipient of this year’s Cottrell College Science Award, which supports the research activities of early-career faculty at primarily undergraduate institutions. Eliza’s successful proposal is entitled “Exoplanet Science with Grinnell’s Grant O. Gale Observatory."
    http://rescorp.org/awards-database/awardee/eliza-kempton

  • Jan. 2015 – Rostom Mbarek receives honorable mention for American Astronomical Society (AAS) Chambliss Student Poster Prize
    Research student Rostom Mbarek was one of 7 undergraduate students awarded honorable mentions for their poster presentations at the AAS winter meeting in Seattle. Rostom’s poster presentation was entitled "Clouds in Super-Earth Atmospheres: Chemical Equilibrium Calculations.”
    https://aas.org/posts/news/2015/01/chambliss-student-poster-awards-aas-225

Full Curriculum Vitae: CV.pdf (Updated June 2016)

Education

  • Harvard University – Ph.D. Astronomy (2009)
    Dissertation: Towards Detecting and Characterizing Earth-like Extrasolar Planets
    Advisors: Dimitar Sasselov & Sara Seager
  • Middlebury College – B.A. Physics, summa cum laude (2003)

Appointments

  • Assistant Professor of Physics – Grinnell College (2012 - present)
  • Sagan Postdoctoral Fellow – UCSC, Department of Astronomy & Astrophysics (2009 - 2012)

Research Interests

  • Theoretical models of planetary atmospheres
  • Detection and characterization of extrasolar planets
  • Transiting extrasolar planets

Honors and Awards

  • Grinnell College Harris Faculty Fellowship (yearlong sabbatical fellowship) (2016 - 2017)
  • Cottrell Scholar Award (Research Corporation) (2016 - 2019)
  • Cottrell College Science Award (Research Corporation) (2015 - 2017)
  • Kavli Frontiers Fellow (National Academy of Sciences) (2010 - 2012)
  • Sagan Postdoctoral Fellowship (2009 - 2012)
  • Harvard University Teaching Certificate of Distinction (2006)
  • Phi Beta Kappa (2003)
  • NSF Research Fellowship Honorable Mention (2003)