Public data release for Galaxy Zoo: Cosmic Dawn!
The below post is by James Pearson (Open University; lead for Galaxy Zoo: Cosmic Dawn data analysis).
We are happy to announce that the classifications for Galaxy Zoo: Cosmic Dawn are now publicly available!
This iteration featured over 41,000 galaxies, using ultra-deep imaging from the Hawaii Twenty Square Degree (H20) survey (a part of the wider Cosmic Dawn survey) to study the Euclid Deep Field North (EDFN), one of the darkest areas of the sky.

More than 10,000 of you contributed almost four million classifications, helping us to find – amongst other things – galaxies with faint (low surface brightness) features and clumps of star formation, as well as more rare objects hidden in this ultra-deep imaging. Your classifications can also help improve the accuracy of machine learning models for faster processing of ever-increasing subject sets, and provide a means of selecting the most interesting objects for further examination with other telescopes. With your help we have already discovered 51 new gravitational lenses – rare phenomena where the light of a distant galaxy is warped into arcs and rings around an intervening galaxy on its path to us, which allow us to study both galaxies in greater detail (in addition to looking pretty!).

This public data release is accompanied by a paper describing the project and some initial analyses of the classifications made by volunteers and by Galaxy Zoo’s machine learning model, Zoobot. You can read the paper (which is under review) on the arXiv at https://arxiv.org/abs/2509.22311.

Thanks again to everyone who contributed their time to making classifications for this project – we really appreciate your participation.
James Pearson, on behalf of the Galaxy Zoo Team
