Hubble Ultra-Deep Field

The Hubble Ultra-Deep Field (HUDF) is a special picture of a tiny part of space in the constellation Fornax. It shows many galaxies, including some that were around 13 billion years ago, just a few hundred million years after the Big Bang. This amazing image was made by the Hubble Space Telescope between September 2003 and January 2004. The first picture was shown to the world on March 9, 2004.

The area of sky where this picture was taken has fewer bright stars. This makes it easier to see the very faint and faraway galaxies. The picture is very small—it is only about one-tenth the width of the full moon as seen from Earth. This tiny patch of sky lets us see back in time to when the universe was much younger.

Over the years, more pictures of this same area were taken using different tools on the Hubble Space Telescope. In 2009, it was observed with infrared light, helping scientists find even more distant galaxies. In 2012, a new version called the eXtreme Deep Field (XDF) showed galaxies from 13.2 billion years ago. In 2014, an image using both ultraviolet and near-infrared light was released. In 2019, an even clearer infrared picture called the ABYSS Hubble Ultra Deep Field was created. This showed that some galaxies are even bigger than we thought.

Planning

After looking at earlier space images, scientists thought they could learn more by looking farther back in time. When a new camera was added to the Hubble Space Telescope, they decided to create an Ultra Deep Field to see very early galaxies.

They had a meeting to plan how to do this study and chose a special area of the sky. This area had very little light from our own galaxy and could be studied by telescopes in both the southern and northern parts of the earth. They picked a spot that had already been studied by other telescopes, which helped them learn more about the very early universe.

Observations

Four filters were used to capture images, focusing on specific colors of light. This helped scientists compare the results with other studies. The telescope was moved slightly between each picture to get the clearest image possible.

The pictures were taken in two periods, first from September to October 2003, and then from December 2003 to January 2004. It took almost 11 days of continuous observation to complete the project. Special tools were used to combine all these pictures into clear, detailed images.

Contents

The Hubble Ultra-Deep Field (HUDF) shows a tiny part of space in the constellation Fornax. It is one of the deepest pictures of the universe ever taken. Scientists used it to look for very old galaxies that existed just a little while after the Big Bang.

The picture shows many objects, most of which are galaxies. Some of these galaxies might be among the farthest we know. One small red star called UDF 2457 is the farthest single star we can see in this picture, located about 59,000 light-years away.

Scientific results

The HUDF showed that many stars were forming very early in the universe, just a billion years after the Big Bang. It helped scientists learn more about how galaxies change over time. The galaxies seen far away were smaller and less shaped than closer galaxies, showing how quickly they changed in the first few billion years after everything began.

Hubble eXtreme Deep Field

The Hubble eXtreme Deep Field (HXDF), released on September 25, 2012, shows a small part of space in the center of the Hubble Ultra Deep Field image. It took two million seconds, or about 23 days, of viewing time over 10 years to capture this picture. The area shown is about 80% of the original Ultra Deep Field and is a very tiny part of the sky — about one thirty-two millionth of it.

The HXDF contains around 5,500 galaxies. Some of the oldest galaxies appear as they were 13.2 billion years ago. The faintest galaxies are so dim that they are one ten-billionth as bright as what we can normally see with our eyes. The red galaxies in the picture are older galaxies that have changed after big collisions. Many of the smaller galaxies are very young and would later grow into larger ones like the Milky Way.