John R. Weaver
Astronomer. Cosmologist. Science Communicator.

I am a Brinson Prize Fellow at MIT’s Kavli Institute for Astrophysics and Space Research. Previously, I was a postdoc at the University of Massachusetts Amherst in Kate Whitaker’s Group. I received my PhD in 2022 from the Cosmic Dawn Center advised by Sune Toft, and my Masters degree in 2018 from the University of St Andrews with Vivienne Wild.
My research lies at the intersection of cosmology and big data. I use the largest telescopes on earth and in space to study the formation and evolution of the most massive galaxies to ever exist. Doing so requires international teamwork, lots of computing hours, and cutting-edge analytical methods.
Currently, I co-lead the Cosmic Dawn Survey, a core element of ESA’s Euclid Mission. I am also the Principal Investigator of Beasts in the Bubbles, a deep JWST program to unearth the secrets of the first galaxies. My previous work building COSMOS2020 has become a benchmark for theory and for planning next generation surveys.
Beyond academia, I have contributed to popular science publications including the astro-ph digest Astrobites, and volunteered extensively at public observatories. I also built AVSpec, the first amateur variable star spectroscopic database for the American Association of Variable Star Observers as the 2016-2018 Mayall Fellow.
news
May 10, 2025 | I’ve been selected as a 2025 Brinson Prize Fellow! |
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Mar 19, 2025 | Euclid’s Quick Release 1 is now live! |
Jan 12, 2025 | Beasts in the Bubbles went to AAS in Washington! |
Sep 16, 2024 | We made some wacky videos about Euclid’s first galaxies! |