The Hubble Ultra-Deep Field (HUDF) is an image of a small region of space in the constellation Fornax, containing an estimated 10,000 galaxies. The original release was combined from Hubble Space Telescope data accumulated over a period from September 24, 2003, through to January 16, 2004. Looking back approximately 13 billion years (between 400 and 800 million years after the Big Bang) it has been used to search for galaxies that existed at that time. The HUDF image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. In August and September 2009, the HUDF field was observed at longer wavelengths (1.0 to 1.6 µm) using the infrared channel of the recently attached Wide Field Camera 3 (WFC3) instrument. When combined with existing HUDF data, astronomers were able to identify a new list of potentially very distant galaxies.Located southwest of Orion in the southern-hemisphere constellation Fornax, the rectangular image is 2.4 arcminutes to an edge, or 3.4 arcminutes diagonally. This is approximately one tenth of the angular diameter of a full moon viewed from Earth (which is less than 34 arcminutes), smaller than 1 sq. mm piece of paper held at 1 meter away, and equal to roughly one twenty-six-millionth of the total area of the sky. The image is oriented so that the upper left corner points toward north (−46.4°) on the celestial sphere.
On September 25, 2012, NASA released a further refined version of the Ultra-Deep Field dubbed the eXtreme Deep Field (XDF). The XDF reveals galaxies that span back 13.2 billion years in time, revealing a galaxy theorized to be formed only 450 million years after the big bang event. On June 3, 2014, NASA released the Hubble Ultra-Deep Field image composed of, for the first time, the full range of ultraviolet to near-infrared light.On January 23, 2019, the Instituto de Astrofísica de Canarias released an even deeper version of the infrared images of the Hubble Ultra Deep Field obtained with the WFC3 instrument, named the ABYSS Hubble Ultra Deep Field. The new images improve the previous reduction of the WFC3/IR images, including careful sky background subtraction around the largest galaxies on the field of view. After this update, some galaxies were found to be almost twice as big as previously measured.
Hubble deep field allowed us to study galaxy evolution from 500 million years onward. Based on my (limited) understanding, I would expect ancient galaxies to contain fewer heavy elements and to have a more "juvenile" appearance, as compared to modern galaxies. Have we actually observed these...
The Hubble telescope was able to capture images of the edges of our visible universe in its deep space photos. These were among its most breathtaking pictures. They show galaxies from about 14 billion light years away, as well as in the past, from the very beginning of time and space in our...
I've recently read that the universe is now estimated to be about 95 billion light years in diameter. This was based on what we now can observe (Hubble Deep Field for example), what is estimated to be seen with new technology (James Webb) and an estimate of what's beyond that which we can't yet...