The Hawaii Two-0 Survey (H20) is a 20 deg2 deep Subaru Hyper-SuprimeCam imaging & Keck DEIMOS spectroscopic survey of the two primary Euclid Deep Calibration Fields (NEP and EDFF).

Euclid Taking Data!

The European Space Agency Euclid Mission successfully launched on July 1, 2023. Read more details on the mission here:

Catalogue Release

The first H20 data catalogue release planned for Fall, 2024.


Hyper Suprime-Cam

Subaru Telescope is the 8.2-meter (320 in) flagship telescope of the National Astronomical Observatory of Japan.



The twin 10-meter Keck Observatory telescopes are among the world’s most scientifically productive optical and infrared telescopes.



The CFH Telescope is a 3.2-meter optical/infrared telescope that is a joint facility of Canada, France, and Hawaii. 

H20 News

Upcoming Catalogue Release

Fall, 2022

The first H20 data catalogue is expected to be completed and released within the coming months. 

NEP Coverage Nearing Completion

October, 2022

CFHT imaging at 100% completion, with HSC imaging and Keck spectroscopy at ~90% and 80% completion respectively.

H20 Overview Paper Submitted

September 27, 2022

“Euclid preparation. Cosmic Dawn Survey: The Hawaii 20-deg2 (H20) Survey Overview” (McPartland et al. 2022) submitted to the Euclid Consortium Editorial Board. 

Grey Murphree’s 699-1 Project Completed

September 16, 2022

Grey’s project, “Measing Linear Galaxy Bias at High Redshift”, is completed and was successfully evaluated by the GROG. 

2021 REU Project Presented at AAS

June 14 2022

Isabella Valdes’s 2021 REU project, “Analysis of ~1500 Massive High-Redshift Galaxies in the Hawaii Twenty Square Degree Survey”, presented at the Summer 2022 AAS conference. 

Science Goals

Galaxy Evolution

Probe the assembly of massive galaxies by tracing the evolution of their stellar mass function with >500,000 galaxies at 3 < z < 6 and including several thousand at z > 6.

Stellar Mass Functions

Link the stellar mass of galaxies to their dark matter halos via clustering, for testing of cosmological models.

Dark Energy

Constrain the properties of dark energy using the non-linear power spectrum at high-redshift.

Galaxy Formation

Identify the earliest sites of galaxy formation and reionization, and spectroscopically confirm high-escape fraction candidates.

Quenching in the Early Universe

Identify and confirm the first galaxies to quench their star formation.

Institute for Astronomy

We are one of the largest university astronomy programs in the world.