Brett M. Morris

Characterizing exoplanets and their host stars

I am a fifth year PhD candidate in the dual-title PhD Astronomy and Astrobiology Program at the University of Washington in Seattle. My research interests sit at the intersection characterizing exoplanets and their host stars. I work with ground and space-based observations to measure the properties of planet-hosting stars, the compositions and structures of exoplanet atmospheres, and exoplanet masses.

You can find my CV in PDF form here, or you can scroll down for an abridged web version.


Starspot Mapping of HAT-P-11

Spot occultations of HAT-P-11

We only know as much about an exoplanet as we know about its host star, which is why I collaborate with Professors Leslie Hebb (HWSC), Suzanne Hawley (UW) and Dr. James Davenport (WWU) on Kepler observations of spotted host stars of transiting planets. Transits allow us to break degeneracies and locate star spots on the surface of the star with precision from photometry alone.

The K4 dwarf HAT-P-11 hosts a hot Neptune planet, which we use as a mini-coronograph to study the starspots of the host star. The spots are distributed in latitude similar to sunspots at solar activity maximum, though the area covered by spots is 100x greater than the typical solar spot coverage. Our analysis of starspots on HAT-P-11 has been published in the Astrophysical Journal, read the paper here.

Chromospheric Activity

CaII H chromospheric activity of HAT-P-11

HAT-P-11 seems to have a Sun-like spot distribution, but is the overall amount of activity on HAT-P-11 normal among stars of its mass and rotation period/age? To find out, I calibrated the APO Echelle Spectrograph to measure Mount Wilson S-indices of chromospheric activity. It seems HAT-P-11 is more active than planet hosts of similar mass and rotation period, and we suggest that the tides induced by the close-in planet may be to blame.

Our analysis of the chromospheric activity of HAT-P-11 has been accepted for publication in the Astrophysical Journal, read the preprint here.

Exoplanet Characterization

Transit Timing Variations


I work with Professor Eric Agol (UW) and Dr. Carolina von Essen (Aarhus University) on characterizing exoplanet systems with transit timing variations with Kepler and ground-based observations from the ARC 3.5m telescope at Apache Point Observatory.

The transit at left is the Earth-sized exoplanet TRAPPIST-1 c, observed with the ARC 3.5 m Telescope at APO with the ARCTIC imager and holographic diffuser.

Transmission spectroscopy

Keck Observatory

I also collaborate with Dr. Avi Mandell (NASA GSFC) on characterizing giant exoplanet atmospheres with transmission spectroscopy in the near-infrared using my own observations from Keck/MOSFIRE (PI Morris, 2014).

Mentorship: Planet hunting

Ada Beale, Doug Branton

I founded and lead the Search for Planets Around post-Main Sequence stars (SPAMS) group at the University of Washington, an undergraduate effort to use small aperture ground-based telescopes to find transiting planets/debris orbiting white dwarfs at short periods.


As a dual-title PhD in astronomy and astrobiology, I am privileged to work with interdisciplinary scientists. For my astrobiology research rotation, I am developing a comprehensive data reduction and analysis pipeline with Professor Jody Deming (UW) on the Submersible Holographic Astrobiology Microscope with Ultraresolution.

I am learning to reconstruct phase and intensity images from a digital holographic microscope, and to develop analysis software scalable to high-throughput computing facilities. The reconstruction pipeline I built, called shampoo, is in active developement and is being used by our research group.


Here's some open source software I wrote to make your day better:

  • astroplan: astropy-affiliated observation planning for astronomers
  • shampoo: digital holographic microscopy and life detection
  • arces_hk: measure chromospheric activity with the ARC 3.5 m Telescope at APO
  • Pre-MAP: my intro to Python curriculum for the 2016 Pre-Major in Astronomy class lots more contributions on GitHub!


I am co-founder/co-organizer/emcee of the popular Astronomy on Tap Seattle public astronomy talk series.

Beginning in 2016, I am a Pacific Science Center Science Communication Fellow

I have been the instructor (2016) and academic mentor (2015) for the UW's Pre-MAP program for freshmen undergraduates with interests in astronomy who are traditionally underrepresented in astronomy. We set them up with (1) computer programming skills, (2) research skills, (3) a research project in their first quarter of their first year with attentive mentorship and peer support.

For fun (and for science!) I maintain a small army of Twitter Bots that do science outreach at all times while I do other things. The army consists of:

  • @planetTVguide: Accounting for light travel time between planets, it tells you when premiere TV broadcasts of historic shows reach known exoplanets in real time
  • @transitingnow: Demonstrating the vast number of transiting exoplanets with real-time tweets when each transiting exoplanet appears to pass in front of its star
  • @farawayplanets: If observers on distant planets had telescopes that could see what is happening on Earth and they looked right now, this is what they would see

In the press: the bots have gotten some attention lately from Popular Mechanics and Vocativ.


See my full list of publications and proceedings here.

First Author

nth Author

You can find my CV in PDF form here.

Selected Proceedings and Proposals