NASA/IPAC Extragalactic Database

Scientists use a big list to study space. This list is kept on a computer. Two men made it a long time ago. It is for things far from our home. It holds data on many far objects. It has many pictures of the sky. It also has many maps. The list helps people learn about space. It is a very helpful tool for science.

Astronomers use a big tool to study the deep sky. It is called the NASA/IPAC Extragalactic Database. People call it NED for short. Two men made NED in the late 1980s. Their names are George Helou and Barry F. Madore. NED is a way to collect facts about objects far away. These objects include galaxies and quasars. NED keeps a master list of these far objects. It tracks their names and where they are. It also tracks redshift. Redshift is a way to measure how objects move. The database has many types of data. It has 1.1 billion distinct objects. It also has 2.6 million images and maps. NED holds 140 thousand links to science papers. It uses data from many different studies. NASA helps pay for the database. The Infrared Processing and Analysis Center runs it. This center is at the California Institute of Technology. NED helps scientists learn about the universe.

Astronomers need a way to study the deep sky. They use a tool called the NASA/IPAC Extragalactic Database. Most people call this tool NED for short. NED is a huge online collection of facts. It focuses on objects far outside our own galaxy. These include galaxies and quasars. It also tracks radio, x-ray, and infrared sources. Scientists use NED to find and study these distant things. It helps them see the big picture of space.

NED works by gathering many different pieces of information. It uses a master list of objects. This list helps scientists match different names to the same object. This is called cross-identification. The database tracks where objects are located in the sky. It also records redshift. Redshift is a way to see how objects move. NED collects data from many different studies. It pulls in images and maps too. This way, all the facts stay in one place.

Two astronomers started this project a long time ago. George Helou and Barry F. Madore created NED. They did this work in the late 1980s. Today, NASA provides the funding for the database. The Infrared Processing and Analysis Center operates the system. This center is located on the campus of the California Institute of Technology. It works under a contract with NASA to keep the data ready for scientists.

The amount of data in NED is truly huge. As of October 2025, it has 1.1 billion distinct objects. It also has 1.5 billion cross-identifications. There are redshift measurements for 19 million objects. The database holds 14 billion photometric data points. It even has 609 million diameter measurements. Scientists can find 2.6 million images and maps there. It also links to 140 thousand journal articles and notes.

NED is part of a larger world of science tools. Other databases help scientists study different parts of space. For example, SIMBAD tracks objects inside our own galaxy. NASA's Planetary Data System tracks things in our solar system. NED is like a giant library for the deep universe. It connects many different studies together. This helps everyone learn more about the stars and galaxies.

The NASA/IPAC Extragalactic Database, or NED, is a massive online resource for astronomers. It serves as a central hub for studying objects located outside our own Milky Way galaxy. These objects are known as extragalactic objects. This category includes galaxies, quasars, and various sources of radio, x-ray, and infrared light. NED is essential because it organizes vast amounts of scattered information into one place. By using this database, scientists can better understand the structure and history of the deep universe.

NED functions through a complex process of data collection and organization. The system is built around a master list of extragalactic objects. One primary task is performing cross-identification. This means the database matches different names used by different researchers to the same single object. NED also records the precise positions of these objects in the sky. It tracks redshift, which is a measurement used to determine how fast an object is moving away from us. Additionally, the database compiles photometric data, which refers to measurements of how much light an object emits at different wavelengths.

The database contains several specific types of scientific data. It includes detailed photometry to show light brightness. It provides accurate position data to locate objects. It also features redshift data to help map the expansion of the universe. Beyond numbers, NED provides visual information through images and maps. These images come from the Digitized Sky Survey, the 2MASS survey, and various scientific publications. This variety allows researchers to study an object through both math and pictures.

The history of NED began in the late 1980s. Two astronomers based in Pasadena, California, started the project. Their names were George Helou and Barry F. Madore. Since its creation, the project has grown into a vital part of modern astronomy. Today, the database is funded by NASA. It is operated by the Infrared Processing and Analysis Center, also known as IPAC. This center is located on the campus of the California Institute of Technology. IPAC manages the database under a formal contract with NASA.

The scale of the data stored in NED is immense. As of October 2025, the database contains 1.1 billion distinct astronomical objects. It manages 1.5 billion cross-identifications across many different wavelengths. The database holds redshift measurements for 19 million objects. There are 14 billion photometric data points and 609 million diameter measurements stored within the system. NED also tracks 250 thousand redshift-independent distances for more than 150 thousand galaxies. Furthermore, it includes 500 thousand detailed classifications for 230 thousand different objects.

NED offers a wealth of secondary resources to help researchers. It provides 2.6 million images, maps, and external links. The database also acts as a gateway to scientific literature. It contains links to 140 thousand journal articles, notes, and abstracts. This connection allows astronomers to move quickly from a data point to a full scientific study. By providing these links, NED helps ensure that data and the research describing it stay connected.

NED is one part of a larger network of astronomical tools. Other databases exist to study different parts of the cosmos. For example, the SIMBAD database tracks objects located within our own galaxy. SIMBAD is maintained by the Centre de Données astronomiques de Strasbourg in France. Another tool is NASA's Planetary Data System, which focuses on objects within our solar system. Finally, the NASA Astrophysics Data System provides bibliographic references. Together, these systems allow scientists to study everything from nearby planets to the most distant galaxies.