Types of Searches

There are many ways to query the NED database. Click on the following Search form or Help links:

  • By Name Search or Help
  • Near Name or Near Position (Cone Search) or Help
  • By Parameters Search or Help**
  • By Classification Search or Help - available in classic UI, porting to new UI in development
  • By Reference Code Search or Help
  • By Input List (Object Name Matches) Search or Help - available in classic UI, porting to new UI in development
  • By Input List (Positional Cross-Matches) Search or Help - available in classic UI, porting to new UI in development
  • By Environment Search or Help - available in classic UI, porting to new UI in development

**Please note that all By Parameters (All-Sky) searches are now queue-scheduled to enable more complex searches and larger search results.


By Object Name

This page allows you to query the NED database by object name. NED's name interpreter recognizes most of the well-known prefixed names used in the literature (e.g., NGC 4151, IRAS F00400+4059, 1ES 0039+409). NED Standard Names has more information on NED's naming conventions.

Data Entry

Type the name of the object you wish to search for in the "Object name" box. The NED interface allows substantial freedom in formats and conventions for names, so type the name in any format you wish. When you submit your search, NED's name interpreter will attempt to translate your input into a name that NED recognizes.

For an ambiguous name (e.g., Andromeda), a drop-down list will be provided with possible names (e.g., Andromeda Galaxy, Andromeda XV, Andromeda Group). Users can conveniently select the intended object to query. If an input name cannot be interpreted at all, an error message will appear indicating the input is not a valid object name.

You may select the preferred Cosmology model under Search Options. NED calculates redshift-based distances and several other cosmology-dependent quantities for your object using the preferred redshift and cosmological parameters that are widely accepted and cited in the astrophysics literature. Pre-selected options available in the form include parameters from: Planck 2015 (2016A&A...594A..13P), WMAP Nine-Year (2013ApJS..208...19H), WMAP Five-Year (2009ApJS..180..330K), and WMAP Three-Year (2007ApJS..170..377S). You may also input cosmological parameters of your own choosing. You may also choose to correct the observed redshift of the galaxy to one of four different reference frames:

  • that defined by the 3K CMB dipole model (see Fixen et al. ApJ 473, 576, 1996);
  • that defined by the Virgo infall only;
  • that defined by the Virgo infall and the Great Attractor;
  • or that defined by the Virgo infall, the Great Attractor, and the Shapley supercluster (see Mould et al. ApJ 529, 786, 2000 for details of the three latter models).

Results

When a search has completed successfully, the interface returns on the same page the overview of the object with data tabs providing detailed data on Cross-IDs, Coordinates, Redshifts, Photometry, Spectra, etc.

Go to Name Search Input Page.
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Near Object Name or Position (Cone Search)

This page allows you to query the NED database for entries near a named object, a given position, or entries whose positions are compatible with an IAU-style positional format you specify. A video tutorial on Cone Search can be accessed here.

Near Name

NED's name interpreter recognizes most of the well-known prefixed names used in the literature (e.g., NGC 224, IRAS F00400+4059, 1ES 0039+409). NED Standard Names has more information on NED's naming conventions.

Data Entry

Select "Near Name Search" from the "Type" box. Type the name of the object you wish to search for in the "Object name" box. The NED interface allows substantial freedom in formats and conventions for names, so type the name in any format you wish. When you submit your search, NED's name interpreter will attempt to translate your input into a name that NED recognizes.

For an ambiguous name (e.g., Andromeda), a drop-down list will be provided with possible names (e.g., Andromeda Galaxy, Andromeda XV, Andromeda Group). Users can conveniently select the intended object to query. If an input name cannot be interpreted at all, an error message will appear indicating the input is not a valid object name.

The input page also allows you to

  • Choose a "Search Radius" (default is 1 arcminute). You may choose any radius for your search up to 60 arcminutes. Be aware that some parts of the sky are very densely populated with objects so that a search with a large radius will take a considerable amount of time. In addition, NED will return up to 50,000 objects with a Near Object Name search.
  • Choose a cosmology model.
  • Constrain your search by
  • Specify your output coordinate system (equatorial, ecliptic, Galactic, or supergalactic) and its equinox (B1950 or J2000; the latter is the default);
  • Change the sort order of the returned object list (default is Distance to search center; options are RA or Longitude in ascending order, Dec or Latitude in ascending order, Galactic Longitude or Latitude in ascending order, and Redshift in ascending or descending order).

Results

When a search has completed successfully, the interface returns on the same page a list of objects that satisfy the search criteria, with their names, positions, object types and redshifts if available; as well as counts of the bibliographic references, notes, positional, photometric, diameter, association, and redshift points available in NED for each object. Clicking on the “Object Name” of each object will open up a new page that provides the detailed information for that object.


Near Position

NED's position interpreter recognizes most of the standard position formats used in the literature.

Data Entry

Select "Near Position Search" from the "Type" box, type in the position around which you wish to search, and specify a search radius up to 60 arcminutes (default is 1 arcminute). Please note that NED is very densely populated in some areas of the sky (e.g., the Hubble Deep Field). Searches in these areas may take several minutes, so you may wish to use a smaller search radius.

Positions may be specified in sexagesimal or decimal mode in most of the usual notations. Examples of supported coordinate formats are

  • 09h55m52.7s +69d40m46s
  • 09:55:52.7 +69:40:46
  • 09 55 52.7 +69 40 46
  • 148.969687d 69.679383d

You may specify the coordinate system you wish to use (equatorial, ecliptic, Galactic, or supergalactic), as well as the equinox of either B1950 or J2000 when applicable. The defaults are "equatorial" and "J2000".

The input page also allows you to

  • Choose a cosmology model.
  • Constrain your search by
  • Specify your output coordinate system (equatorial, ecliptic, Galactic, or supergalactic) and its equinox (B1950 or J2000);
  • Change the sort order of the returned object list (default is Distance to search center; options are RA or Longitude in ascending order, Dec or Latitude in ascending order, Galactic Longitude or Latitude in ascending order, and Redshift in ascending or descending order).

Results

When a search has completed successfully, the interface returns on the same page a list of objects that satisfy the search criteria, with their names, positions, object types, and redshifts if available; as well as counts of the bibliographic references, notes, positional, photometric, diameter, association, and redshift points available in NED for each object. Clicking on the “Object Name” of each object will open up a new page that provides the detailed information for that object.


By IAU-style Format

NED allows two interpreters for the IAU-style positional formats: one uses a strict interpretation of the IAU conventions, while the other is more liberal in its assumptions concerning the rounding, truncating, etc.

Data Entry

Select "IAU Search" from the "Type" box, and enter your IAU-style format in the input box. Acceptable formats are

  • HHMM+DD
  • HHMM+DDd
  • HHMMd+DDd
  • HHMMd+DDMM
  • HHMMSS+DDMMd

and so on, using standard sexagesimal notation for equatorial coordinates (the lower case "d" is a decimal integer between 0 and 9). NED assumes the name is in the equinox specified in the "Equinox" box below. NED has kept B1950 as the default equinox for IAU searches to remain consistent with IAU naming conventions.

Click on the "Strict" or "Liberal" button to select the interpretation you desire for your search (the default is the literal interpretation).

The input page also allows you to

  • Choose a cosmology model.
  • Constrain your search by
  • Specify your output coordinate system (equatorial, ecliptic, Galactic, or supergalactic). Equinox is assumed to be the same as input.
  • Change the sort order of the returned object list (default is Distance to search center; options are RA or Longitude in ascending order, Dec or Latitude in ascending order, Galactic Longitude or Latitude in ascending order, and Redshift in ascending or descending order).

Results

When a search has completed successfully, the interface returns on the same page a list of objects that satisfy the search criteria, with their names, positions, object types, and redshifts if available; as well as counts of the bibliographic references, notes, positional, photometric, diameter, association, and redshift points available in NED for each object. Clicking on the “Object Name” of each object will open up a new page that provides the detailed information for that object.

Go to Near Name or Position (Cone Search) Input Page.
Return to beginning of this help page.
Return to NED's Home Page.


By Reference Code

This window allows you to query the NED database by journal reference code (catalogs, books, and theses cannot yet be searched using this option). The 19-digit Reference Code is referred to as the BIBCODE in ADS and SIMBAD.

Data Entry

Reference codes are sensitive to upper and lower case characters, so they must be entered exactly for a match to occur.

In the "Reference code" box, type the 19-digit NED reference code for the journal article you wish to search. Reference Codes has detailed information on how references are coded in NED.

Results

When a search has completed successfully, the interface returns on the same page a list of objects that satisfy the search criteria, with their names, positions, object types, and redshifts if available; as well as counts of the bibliographic references, notes, positional, photometric, diameter, association, and redshift points available in NED for each object. Clicking on the “Object Name” of each object will open up a new page that provides the detailed information for that object.

There is a limit of 1,000 records for the displayed search results. The full result can be downloaded via the resource link above the data display area when the returned number of objects is over 1,000 but under 100,000. When the returned number of objects exceeds 100,000, please contact the NED helpdesk for further assistance.

Notes on Reference Code searches

You may also do a search for objects in a journal article from the lists returned by searches for references. In those cases, you will not need to type in the reference code as you must on this page.

All objects mentioned in a given paper are not necessarily entered into NED. For example, we do not enter objects identified in a paper as Galactic stars in the fields of radio sources, but we do enter the objects identified as extragalactic in the same paper. Also, NED usually does not carry references for objects mentioned "casually" within a paper.

Go to By Reference Code Input Search Page.
Return to beginning of this help page.
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By Parameters (Advanced All-Sky) Search

This page allows you to query the NED database for entries constrained by Sky Area, Redshift, Photometry, Object Type and Name Prefix.

Data Entry

Sky area constraints may be specified in either Equatorial (J2000) or Galactic coordinates (or both) using the "Between" option, then entering your coordinate limits in the boxes. Declination and Galactic Latitude also offer a "Not Between" option which allows you to exclude a strip of Declination or Galactic Latitude from your search. Positions may be specified in sexagesimal or decimal mode in most of the usual notations.

Set your redshift constraints, if any, in z or km/sec. The default is to have no redshift constraint.

Set your photometric constraints (by flux density or magnitude) from among the available options. "Brighter Than" and "Fainter Than" require a number in the first box following the button; "Between" and "Not Between" require numbers in both boxes following the button. Next, choose the units you wish to search by (flux density or magnitude). Finally, choose the wavelength range -- or waveband in a particular wavelength range -- within which you wish to search NED.

You may also constrain your search by object type (e.g., "RadioS", "IrS", "GPair"; see Notes on Using Object Type Constraints for more information on object type constraints) and name prefix (e.g., "IRAS", "87GB", "UGC"; see Notes on Excluding Objects Using Name Prefixes for more information on using the name prefix constraint). The default is to have no constraint.

The input page also allows you to

  • Choose a cosmology model.
  • Specify your output coordinate system (equatorial, ecliptic, Galactic, or supergalactic) and its equinox (B1950 or J2000) when applicable.
  • Change the sort order of the returned object list (options are RA or Longitude in ascending order, Dec or Latitude in ascending order, Galactic Longitude or Latitude in ascending order, and Redshift in ascending or descending order).
  • Choose the format of your tabular data to be
    • an ASCII bar-separated variable table of the list of sources,
    • an ASCII tab-separated variable table of the list of sources, or
    • an XML table, in VOTable format, of the list of sources.

Scheduling and Queueing

All By Parameters (All-Sky) searches are submitted to the NED Backgrounding with Automated Scheduling and Queuing system (NBASQ). This system allows more complex, multi-parameter searches, or searches with large results sets to run to completion.

Upon submitting a query, you will see the Job Status displayed. This contains a table with the Job Ticket, Status, Submission Time, Execution Time, Wait Time, and Run Time. A description of the query is given, which you should check to make sure the search parameters were correctly entered. The Job Status (Accepted, Queued, Running, or Complete) tells you how your query is progressing. The Job Status page will update at intervals of roughly 10 seconds.

This will be followed by the NBASQ Job Report, upon completion of the job. You will find the Result Size (bytes) and Filetype at the bottom of the Job Report Table. Results are retrieved by clicking the "Download" link, found directly below the Status table.

Please make a note of the "Ticket" string in the Job Status or Job Report table, for later reference. You may exit your browser and retrieve the results of your query at a later time using this Ticket. Go to Ticket Status under the "Services" tab of the NED user interface, then enter the Ticket string.

If your query does not successfully complete, and you have checked that you have entered the query correctly, you may contact NED to request a special token required for lengthy queries (those that require an hour or more to execute).

Results

Results are delivered in the format specified under the "Output Options" button on the By Parameters (All-Sky) Form. Information listed for the objects meeting your search criteria includes their positions, a redshift if available, and one of their names in NED, as well as counts of the bibliographic, notes, positional, photometric, and redshift references available in NED for the object.

CAUTION

Searches returning more than a few thousand objects will take several minutes to complete. While network and database loads will play a role in determining the apparent speed of the search, the largest single factor is the number of objects returned. If you know that your search will yield a large number of objects, it may be more convenient for you to split your search into smaller ones.

Go to By Parameters Search Input Page.
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By Classifications, Types, Attributes - porting to new UI in development

This window allows searches for all objects with specific classifications, types, or attributes, e.g. optical morphology or spectral classification. Currently, NED has classifications and attributes at all wavelengths from several large catalogs and hundreds of literature papers; a complete list of references is available here, as well as on the search input page. Not every object in these publications has a listed attribute, and not all attributes listed in the publications are included in NED's current release.

Data Entry

You may optionally customize your output table. First, choose the type of output table you want (default is bar-delimited hypertext). You may choose bar, tab, or space delimited tables in plain (7-bit ASCII) text, or with hypertext links included.

Note that while tab- and space-delimited tables may be displayed identically by your browser, they are stored differently as files. If you intend to save and work with the data in your files, please be aware of the difference.

The hypertext-links display shows error or warning messages, and essential notes, as links; "hover" your cursor over the link to show the message or note. Plain ASCII text spells out the error/warning message, or note, in full in the table.

Select the Standard Information you need. This includes data that appears on the main results page of a typical NED query for a single object.

Detailed Information from three of NED's tables of detailed data is currently available -- classifications, photometry, and diameters. You may "Select All" (or clear the list with "Deselect All"), or choose the individual data types that you wish to have data for.

To display your choices of detailed data, click the "NED Homogenized" boxes at the bottom of the "Classifications", "Photometry", or "Diameters" columns. You may also choose to display classification reference codes, published values of the photometry and its uncertainty, the major diameter uncertainties, the axis ratios, and the position angles.

Select type constraints. There are currently (November 2010) seven sections, each with several sub-sections:

  • Galaxy Morphology
  • Radio Morphology
  • Distance Indicator
  • Activity Type
  • Luminosity Class
  • Kinematics
  • Hierarchy

A clickable "Index" of type constraints will take you to any section. Once there, clicking on the "Show/Hide" links will show the additional options available in each sub-section.

Most option boxes are followed by a superscripted "[i]nformation" link that will give a description of the particular classification or attribute. This includes a summary list of NED's available holdings, with references, for the particular classification. You will also be able to retrieve a complete list of objects with those classifications/attributes using this information link.

Clicking the "Reset" button will clear all the selections.

Click the "Submit Query" button to begin your search.

Results

When a search has completed successfully, the interface opens a new page with a list of objects with their names, positions, preferred object types, morphological and/or spectral types as available, redshifts if available (with optional redshift quality flags), and magnitudes and (optionally) filters. Also given are counts of the bibliographic, notes, positional, photometric, redshift, diameter, and association references available; and links to retrieve images, spectra, and classifications. An index number appears at the beginning and end of each line; clicking on this will retrieve NED's basic data for each object, as well as web links to many other online services that may have more information about the object.

Go to the Classifications, Types, and Attributes Search Input Page.
Return to beginning of this help page.
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Notes on Excluding Objects Using Name Prefixes

There are two ways to exclude objects from your searches based on their catalog name prefixes.

  • Exclude objects no matter how many name prefixes they have in NED, or
  • Exclude objects with only one name prefix in NED.

In the first case, any object carrying (for example) an "APMUKS" name prefix will not be returned by your search even if that object also carries other names in NED. In the second case, only those objects with just one name in NED will be excluded.

In either case, highlight -- in the list of name prefixes -- those catalogs that you wish to exclude.

The "Quick-Pick Deep Surveys" bar highlights several catalogs that include many objects with only one name in NED. Clicking this bar also chooses the "Exclude objects that have only one name" option since the "quick-pick" bar is only applicable with this particular exclude option.

Large catalogs currently on the "Quick-Pick Deep Surveys" list are APMUKS, FIRST, LCRS, MAPS, MDS, NGPFG, NGP9, NVSS, SDSS, 2MASS, 2QZ, and 2dFGRS. These catalogs have very high object densities on the sky, and can fill your search lists with many faint objects in which you may have no interest. For example, excluding "APMUKS" from searches in the southern sky, or "NVSS" in the northern sky, will typically exclude most of the objects in a search field.

To browse and search a complete list of name prefixes recognized by NED's name interpreter, use the Source Nomenclature service, which is available in the main menu under Information >> Holdings >> Nomenclature.


Notes on Using Object Type Constraints

Select "Union" to join checked object types with logical ORs. For example, you might want to find all objects that are galaxies OR infrared sources OR radio sources within 30 arcminutes of NGC 4151. Select "Intersection" to join checked object types with logical ANDs. This type of search will return, for example, only those objects within 30 arcminutes of NGC 4151 that are galaxies AND infrared sources AND radio sources.

To insure this flexibility, object type constraints use the object types attached to each name rather than the Preferred Object Type. Thus, the name NGC 4151 carries the object type "Galaxy", but the NED object is also an infrared source (2MASX J12103265+3924207), a radio source (87GB 120800.7+394100), a visual source (UITBOC 1694), and an X-ray source (RX J1210.5+3924). Searching for any of these object types in the area around NGC 4151 will return NGC 4151 itself, even though its preferred object type is "Galaxy".


NED Standard Names

Object names are generally separated into catalog identifier and member identifier. The name interpreter checks the catalog identifier to certify that it points uniquely to a catalog recognized by the database. The name interpreter then checks the member identifier to certify that it corresponds to the conventions of the catalog identified (e.g. is it a sequential number, or a combination of numbers and letters, etc?), and that it does not exceed certain limits (e.g. the number of objects in catalog). The left hand column of the following table contains examples of input names recognized by the interpreter. The right hand column shows the NED standard formats.

n33 NGC 0033
U 12 UGC 00012
M81 MESSIER 081
mk1000 MRK 1000
M 3-4-5 MCG +03-04-005
ZW23.1 CGCG 023-001
1zw23 I Zw 023
PKS0350+23 PKS 0350+23
4C23.7 4C +23.07

Names with square bracket prefixes (e.g. "[HB89]" and "[WB92]") usually come from papers published in journals, while those names with unbracketed prefixes (e.g. "NGC" and "IRAS") usually come from separately published catalogs. There are exceptions, however; examples include "[RC2]" and "87GB". Some names have combination prefixes (e.g. "87GB[BWE91]" and "ABELL 0400:[D80]").

Objects in multiple systems without existing unique names are formed by the name of the system itself followed by "NEDnn", where "nn" is a decimal number starting with "01" (example: "ARP 294 NED01" and "ARP 294 NED02"). Similarly, objects found only in catalog notes are given names beginning with the name of the cataloged object followed by "NOTESnn" (example: "UGC 01562 NOTES01" and "UGC 01562 NOTES02"). Sources named in non-optical catalogs or lists, which are later found to be coincident with galaxies but which are not renamed, have "ID" appended to their original names (example: "IRAS 04356+3412 ID"). In this case, the Preferred Object Type is also changed to "Galaxy". Additional suffixes to any object name include ABSnn, FG, BG, ARCnn, BCGnn, HOST, CLUSTER, and others.

Note that recognition by the interface of the nomenclature used for the object name
does not guarantee that the name exists in the Database. This recognition signals that
at present parts of the catalog are in the Database, and that the intent is to eventually
include at least the extragalactic portion of that catalog in NED.

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Coding NED References

Working with the editors of The Astrophysical Journal and The Astronomical Journal, with the SIMBAD group at Centre Donnees Stellaire in Strasbourg, and with the Astrophysics Data System group at the Harvard/Smithsonian Center for Astrophysics in Cambridge, Massachusetts; NED has developed a flexible coding method which concisely describes astronomical bibliographic references. This method of coding references has been adopted by all of these organizations.

NED reference codes are 19-digit strings of the form

YYYYPUBLNVVVVMPPPPA

Unused characters are padded with dots ".". The fields within the string are as follows:

YYYY The four digits of the year of publication.
PUBLN The journal code, left-justified within the five-digit field. The codes for those journals regularly
entered into NED are:
A&A.. Astronomy and Astrophysics
A&AS. Astronomy and Astrophysics SupplementSeries
AJ... Astronomical Journal
ApJ.. Astrophysical Journal
ApJS. Astrophysical Journal SupplementSeries
ARep. Astronomy Reports (formerly Soviet Astronomy)
AstL. Astronomy Letters (formerly Soviet Astronomy Letters)
IAUC. IAU Circulars
MNRAS Monthly Notices of the Royal Astronomical Society
PASP. Publications of the Astronomical Society of the Pacific
PASJ. Publications of the Astronomical Society of Japan
VVVV Volume number of the journal, right-justified within the four-digit field.
M Tie-breaker code. Where ambiguity is possible (e.g. between the main journal section, and the
"pink pages" section of MNRAS), the following characters or digits in this field break the ambiguity:
L Letters sections in various journals.
p Pink pages in MNRAS.
1, 2, ..., 9,0,
a, b, ..., o
Issue numbers 1 through 0, then a through o, within the same volume of a journal (e.g. Sky and
Telescope, Physics Today).
A, B, ... Issue designations used by the publisher within the same volume, where each issue starts with
page one.
q, r, ..., z Two or more articles appearing on the same page within a single issue of a journal (e.g. Nature,
IAU Accouncement Card) are lettered successively beginning with q, extending through z.
PPPP First page number of the article, right-justified.
A First letter of the first author's last name, or a ":" when no authors are specified for a reference.

Here are some examples:

1986MNRAS.221p..41H Hawarden, T. et al. 1986, Monthly Notices of the Royal Astronomical Society, 221, 41p.
1988ApJ...324..767W Ward, M. et al. 1988, Astrophysical Journal, 324, 767.
1990A&A...228...42B Binggeli, B. et al. 1990, Astronomy and Astrophysics, 228, 42.
1992ApJ...385L..37K Knapen, J. et al. 1992, Astrophysical Journal (Letters), 385, L37.
1992MNRAS.257..677W Winkler, H. 1992, Monthly Notices of the Royal Astronomical Society, 257, 677.
1992PASJ...43L..57S Sofue, Y. and Wakamatsu, K.-I. 1992, Publications of the Astronomical Society of Japan,
43, L57.
1993IAUC.5731....1R Ripero, J. 1993, IAU Circular No. 5731.

More information about the reference codes can be found in a paper by the NED group.

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