The Hubble Space telescope has been our eye in the sky for almost 30 years, and it's still consistently producing some of the best images of the cosmos. Now, astronomers from the Instituto de Astrofísica de Canarias (IAC) have re-processed an old Hubble Ultra-Deep Field (HUDF) image to find new details. The end result is the deepest image ever taken of the universe from space.

The original HUDF was captured in 2004, as Hubble stared at a tiny patch of sky for hundreds of hours and took a long exposure shot to peer further into space than ever before. After the Wide Field Camera 3 (WFC3) was installed on the spacecraft in 2009, it too was trained on the same spot for twice as long, and extended that depth even further in a 2012 photograph.

The new project updates that image yet again. Over the past three years, researchers at the IAC have used a new method of combining the individual images. This technique helps to recover the "lost light" that obscured some of the more faint objects.

"What we have done is to go back to the archive of the original images, directly as observed by the HST, and improve the process of combination, aiming at the best image quality not only for the more distant smaller galaxies but also for the extended regions of the largest galaxies," says Alejandro Borlaff, lead researcher on the new study.

Over the entire final image, the team managed to recover the equivalent light of an entire galaxy – roughly 100 thousand million Suns-worth. Along with revealing new galaxies, the extra light also showed that some of the previously-spotted galaxies were up to twice as wide as once thought.

The new image is described in a paper published in the journal Astronomy & Astrophysics.

Source: IAC