John R. Weaver

Astronomer. Cosmologist. Science Communicator.

prof_pic.jpg

I am 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

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!

selected publications

  1. COSMOS2020: A Panchromatic View of the Universe to z∼10 from Two Complementary Catalogs
    J. R. Weaver, O. B. Kauffmann, O. Ilbert, H. J. McCracken, A. Moneti, and 53 more authors
    The Astrophysical Journal Supplement Series, Jan 2022
  2. A&A
    2023A&A...677A.184W/2023A&A...677A.184W.jpg
    COSMOS2020: The galaxy stellar mass function. The assembly and star formation cessation of galaxies at 0.2< z ≤ 7.5
    J. R. Weaver, I. Davidzon, S. Toft, O. Ilbert, H. J. McCracken, and 28 more authors
    Astronomy & Astrophysics, Sep 2023
  3. The UNCOVER Survey: A First-look HST + JWST Catalog of 60,000 Galaxies near A2744 and beyond
    John R. Weaver, Sam E. Cutler, Richard Pan, Katherine E. Whitaker, Ivo Labbé, and 41 more authors
    The Astrophysical Journal Supplement Series, Jan 2024