NASA/IPAC Extragalactic Database

About NED

Vision

The NASA/IPAC Extragalactic Database (NED) aims to capture the most reliable census of extragalactic objects and provide essential data and tools to facilitate astrophysics research and exploration.

Mission

NED accelerates science discovery in astrophysics within NASA’s strategic plan by providing a census of extragalactic objects augmented with data joined from across the electromagnetic spectrum for use by the research and lay communities worldwide with access through computer query protocols and user-friendly interfaces. This data synthesis is continually updated by the fusion of fundamental data, prioritizing objects with measured redshifts and distances in refereed publications and major catalogs, and by providing external links to additional data. NED provides its reliable compendium and suite of query tools for many research areas including spectral energy distributions, statistical studies, and time-domain astronomy.

Using NED

The database content includes a master index of distinct astrophysical objects, multiwavelength cross-identifications, associations, positions, redshifts, redshift-independent distances, photometry, diameters, images, spectra, and detailed notes. NED Holdings provides counts and graphics of the current content in NED, describes how data are integrated into NED, and also supplies explantions on NED's processing of large data sets. Derived quantities include Galactic Extinction, velocity corrections, Hubble Flow distances and scales, cosmological corrections, quick-look luminosities, and spectral energy distributions (SEDs).

Objects can be queried By Name, Near Name or Near Position (Cone), or In Refcode. Galaxy samples can be constructed By Parameter constraints on Sky Area, Redshift, Flux Density (Magnitude), Object Types, and Survey Names, or by galaxy Classifications and Attributes. More on the usage of NED can be found at User Guides.

NED's data and references are continually updated in an internal production database, and revised versions are released on the public website every few months. New or improved science functionality is also released on a regular basis.

Automated Queries

Automated access to NED's Web services using computer programs and scripts is supported. See NED Program Interface for further information. Please adhere to the NED Guidelines for Automated Queries as NED's ability to support automated access involving large data volumes or high query rates is limited.

Acknowledging NED

If your research benefits from the use of NED, an Acknowledgement would be appreciated.

Last Change: 2025-03-20