Hubble Ultra-Deep Field

The Hubble Ultra-Deep Field (HUDF) is an image taken by the Hubble Space Telescope (HST) between September 23, 2003 and January 15, 2004. The target field (a 200×200 arcsecond field at right ascension, 3h32m39.0s and declination, +27deg47m29.1s) was chosen to avoid nearby bright stars and Milky Way dust. Four images were made with the ACS camera, 435 nm (aka, B-band), 606 nm (aka, V-band), 775 nm (aka, i-band), and 850 nm (aka, z-band). The image has 10,000 galaxies. The HUDF was undoubtedly an effort to repeat and surpass the Hubble Deep Field (HDF) in providing unprecedented research data.

A follow-up survey is HUDF09, images using the later WFC3 camera: 1050 nm (aka Y-band), 1250 nm (aka J-band), and 1600 nm (aka H-band), specifically to find the highest redshifted galaxies possible: a galaxy not showing in the a Y-band image suggests a z ≥ 8 and if it also doesn't show in the J-band, a z of 10 is suggested. Other subsequent surveys have included the field.

The HXDF (Hubble Extreme Deep Field or XDF) released in 2012 is a portion of the HUDF.