• I am an Associate Professor in the Department of Astronomy at Cornell University. I'm also affiliated with the Cornell Center for Astrophysics and Planetary Science and the Carl Sagan Institute.
  • My curriculum vitae (PDF, April 2024).
  • A full curriculum vitae, including publications (PDF, April 2024).
  • My current contact information.
• 2009-2025: I was a Principal Research Scientist (and before that, a Senior Research Associate and a Research Associate) at the Cornell Center for Astrophysics and Planetary Science. I was also a Research Professor in the Department of Astronomy from 2022 to 2025.
• 2008-2009: I was briefly a Research Scientist and Queen Elizabeth II Fellow at the Australia Telescope National Facility.
• 2006-2008: University Postdoctoral Fellow at the University of Sydney, Australia.
• 2003-2006: Jansky Fellow at the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA, and the National Radio Astronomy Observatory in Socorro, NM.
• 2003: Ph.D. in Astronomy at Cornell University, where I worked with Jim Cordes.

• My CV (PDF) includes a list of high-impact publications; or see a full list of publications here.
• I am a member of the NANOGrav collaboration. With our 15-year data release, we reported evidence for a stochastic background of gravitational waves at nanohertz frequencies, as detected using pulsars as precise astrophysical clocks. (Articles in the New York Times, Washington Post, Scientific American, and more.)
• I gave a talk about pulsar timing arrays and the NANOGrav project as part of the Talks at Google series, which you can watch on YouTube:
  "Building a Galaxy-Scale Gravitational Wave Detector".

• We found a fast radio burst (FRB 121102) at Arecibo - a millisecond flash of radio waves coming from beyond our Galaxy, and showed that unlike all the previously discovered FRBs, this one was a repeating source.
  (Spitler et al. 2016, Nature; articles in Scientific American, National Geographic.)
• With incredibly data-intensive observations at the Very Large Array, we pinpointed the source of the fast radio burst FRB 121102, and showed that it is located in a distant dwarf galaxy about a billion parsecs away.
  (Chatterjee et al. 2017, Nature; Tendulkar et al. 2017, Astrophysical Journal Letters; a gorgeous Nature cover image, and articles in the New York Times, Washington Post, National Geographic, CNN, etc.)
• In a twist to the story, we used observations at Arecibo to show that the radio waves in the bursts were twisted (i.e., the polarization showed extreme Faraday rotation) by their passage through an intensely magnetized region. The bursts must originate in the environment of a massive black hole, or in an unprecedented pulsar wind nebula / supernova remnant.
  (Michilli et al. 2018, Nature; another gorgeous Nature cover image, and articles in the New York Times, Washington Post, Scientific American, BBC, etc.)
• A hammer and a feather fall at the same rate under gravity (in a vacuum). But is this Principle of Equivalence true even if the objects are massive enough to have significant self-gravity? We found a pulsar orbiting in a triple system with two white dwarfs, which enables such a test.
  (Ransom et al. 2014, Nature.)
• Our searches for pulsars with the Arecibo radio telescope have involved major technical advances and revealed some other extraordinary systems:
  • An eccentric binary pulsar in the Galactic plane (Champion et al. 2008, Science).
  • A binary neutron star pair with extremely asymmetric masses, that points to a progenitor population for LIGO-detected neutron star mergers with significant electromagnetic counterparts (Ferdman et al. 2020, Nature).
  • Thousands of volunteers from 192 countries around the world have helped us find pulsars at Arecibo as part of the Einstein@Home project! (Knispel et al. 2010, Science.)
• The ultra-high velocity pulsar B1508+55 is escaping our Milky Way at over 1000 km/sec!
  (Chatterjee et al. 2005, in the Astrophysical Journal Letters; articles in New Scientist, Discover magazine, and even Slashdot!)
• The gorgeous Guitar nebula is a bow shock nebula produced by another ultra-high velocity pulsar, B2224+65.
  (Chatterjee & Cordes 2002, Chatterjee & Cordes 2004.)
• I run the FRB Community Newsletter with Emily Petroff. You can sign up for the (approximately monthly) mailings at this subscription form.
• I maintain a list of all reliably-measured neutron star parallaxes (or here). If you're starting out on a pulsar-related research project, I also maintain an introductory reading list for pulsars.

Courses I have taught recently:

• Astronomy 1102: Our Solar System. (Recently: Spring 2025)
• Astronomy 1199: Are We Alone? The Search for Life in the Universe.
• Astronomy 2201: The History of the Universe.
• Astronomy 2299: The Search for Life in the Universe.
• Astronomy 4523 / 6523: Modeling, Data Mining, and Machine Learning in Astronomy (Next: Fall 2025)
• Astronomy 6525: Techniques of Optical/Infrared, Submillimeter, and Radio Astronomy.

• I put together a Cornell letterhead LaTeX template that complies with the official Cornell style guide.
• A long time ago I helped assemble The Graduate Student's Guide to Cornell Astronomy.
• Back in the days of film, I scanned in some of my photographs from New Mexico, Puerto Rico, Crete and Athens, Beijing, and wiping out while skiing, as well as some of our telescopes.
• We had a blog about our life in Sydney, including vital information about how to eat passionfruit and how to handle a baby wombat.
• I occasionally post to my Instagram feed, and I sometimes log my solutions to various computer and software issues.