mapping the Universe
in search of nearby worlds
I specialize in making and analyzing high-resolution maps from large astronomical survey data sets. Much of my work has focused on processing infrared images from NASA's NEOWISE mission, repurposing this vast asteroid-hunting data set for astrophysics beyond the inner solar system. I am using NEOWISE data to search for cold nearby worlds, including brown dwarfs in the solar neighborhood, wide substellar companions, and the hypothesized Planet Nine. I also play a key role in several wide-area optical imaging surveys, particularly DECaLS and MzLS.
I'm currently a staff astronomer at NSF's NOIRLab (formerly NOAO), where I previously spent a year as a NASA Hubble Fellow. At NOIRLab, I am a member of Rubin Observatory's Community Science Team (CST). I earned a Ph.D. in physics from Harvard University in 2015. Before that I was an undergraduate at Stanford University, where I received a B.S. in physics in 2010.
I'm the PI of this new NASA-funded citizen science project, coming soon to Zooniverse!
I'm a core member of the DESI imaging surveys team, producing optical catalogs 1.5-2 mags deeper than SDSS across 20,000 square degrees of sky.
I was a core member of the Dark Energy Spectroscopic Instrument (DESI) commissioning team. My first-author SPIE paper shows a small sampling of my DESI commissioning work.
I'm the PI of an approved Cycle 2 JWST program to obtain the first spectrum of the coldest known halo brown dwarf (WISEA 1534-1043 a.k.a. "The Accident").
I've reprocessed more than 300 terabytes of WISE images to create the deepest ever full-sky maps at 3-5 microns.
I'm the PI of an approved Spitzer program that has imaged hundreds of extremely cold and fast-moving brown dwarf candidates newly revealed by combining the full WISE and NEOWISE data sets.
I have performed the deepest and widest area WISE-based search for Planet Nine.
We have published the deepest ever 3-5 micron full-sky catalog, featuring over 2 billion unique WISE-selected sources.
A full-sky, time-domain version of the unWISE Catalog.
I created a full-sky, high-resolution map of mid-infrared dust emission.
Accurate motion measurements for more than a billion infrared sources based on my time-resolved WISE coadds.
My work, particularly in relation to citizen science, "big data", high performance computing, and Planet Nine, has been widely featured in local, national and international media. A partial list of articles quoting or mentioning me by name is provided below. I have also discussed my research during a number of radio and television appearances.
Newsweek : What's your moonshot? Aaron Meisner and Backyard Worlds Want to Discover Our Solar System's Ninth Planet
CNN : Citizen scientists help discover 95 brown dwarfs that are neighbors of our sun
CBC Radio One : Amateur astronomers use the 'mark one eyeball' to find brown dwarf stars
NASA Feature : Citizen Scientists Help Create 3D Map of Cosmic Neighborhood
BBC : Backyard Worlds: One hundred new 'cool worlds' discovered
KGUN9 Tucson : Astronomers are trying to measure the effects of dark energy on the expansion of the universe
Berkeley News : UC Berkeley, NASA looking for citizen scientists to help find Planet 9
Scientific American : Looking for Planet Nine, Astronomers Gaze into the Abyss
NASA Feature : NASA-funded Website Lets Public Search for New Nearby Worlds
Berkeley Lab : Attention Earthlings: Help Wanted in Finding a New Planet
USA Today : NASA wants you - to find a missing planet
Daily Cal : Two UC Berkeley Researchers Recognized in Forbes '30 Under 30 in Science' List
HubbleSite : NASA Awards Prestigious Postdoctoral Fellowships
Die Welt : Jeder soll bei der Jagd auf Planet Neun mithelfen
I co-founded Backyard Worlds: Planet 9, a Zooniverse project consisting of an all-sky crowdsourced motion search built around my time-resolved WISE/NEOWISE coadds. Since launching in February 2017, over 150,000 citizen scientists have contributed to our total of more than 8 million classifications. These contributors include residents of all 50 US states and 167 countries. Backyard Worlds now counts 78,000 registered users, and has benefited enormously from the enthusiasm and dedication of our diverse group of volunteers, some of whom have gone on to receive media recognition for their participation. Four citizen scientists are co-authors on the project's first peer-reviewed publication.
Credit: NASA's Goddard Space Flight Center Conceptual Image Lab/Krystofer D.J. Kim
Full-sky WISE/NEOWISE-Reactivation Coadds: unwise.me, portal.nersc.gov, IRSA
Full-sky, Time-domain, Mid-infrared unTimely Catalog, portal.nersc.gov, GitHub
Full-sky, WISE-selected "unWISE Catalog": catalog.unwise.me, Astro Data Lab, IRSA, Vizier
DESI imaging surveys DR1-DR9: legacysurvey.org, Astro Data Lab
Full-sky CatWISE proper motion catalog: catwise.github.io, Astro Data Lab, Vizier
Planck Full-sky Dust Model: planck.skymaps.info
WISE Full-sky 12 micron Dust Emission Map: wise.skymaps.info
DECam Galactic Plane Survey (DECaPS): decaps.skymaps.info, Astro Data Lab
NOIRLab Source Catalog: datalab.noirlab.edu