Types of Searches
There are many ways to search NED's master directory
of extragalactic objects. 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. This search option also requires a token to
be entered at the bottom of the By Parameters Form.
This page allows you to search NED's master list of extragalactic
astronomical objects by object 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
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.
If it cannot interpret the name you typed, a page will appear
with a message explaining the most likely problem with your input.
These usually fall into three categories. In all three cases, click
your browser's "Back" button to go back to the search page, and enter
another object name.
(1) If the name you entered has an
acceptable catalog name, but the object number within the catalog is
not within the range of numbers for that catalog, the page will tell
you this. An example is "M111"; there are only 110 entries in the Messier
catalog.
(2) If the catalog name itself is ambiguous, the page will list the
acceptable possibilities. An example is "A123"; this could be
"Abell 123", "Arakelian 123", "Arp 123", "Asiago1 023", or "[RC1]
A1203".
(3) If the name interpreter does not recognize the catalog, the page
will sometimes suggest alternative catalogs, sometimes not. In
either case, click the "Back" button and try another name.
You may set two other input options on this page:
- "Extended Name Search?" (default is "No"). If "Yes", your search
will return all objects beginning with the name you entered. For
example, "ABELL 400" will return not only "ABELL 0400", but also "ABELL
0400:[D80] 01", "ABELL 0400:[D80] 02", and so forth. Similarly, a
search for "Arp 294" will return not only "ARP 294", but "ARP 294
NED01" and "ARP 294 NED02". NED Standard
Names has more details on these extensions.
- Cosmology model: 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.
NOTICE: As of the 2018 September NED release, the previous default
cosmological parameters from WMAP Three-Year results have been replaced
with the Planck 2015 results..
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).
The input page also allows you to
- Specify your output coordinate system (equatorial, ecliptic,
Galactic, or supergalactic) and its equinox (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or
J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
Results
When a search has completed successfully, the interface opens a new page
with the object's name, position, redshift if available;
as well as counts of the bibliographic, notes, positional, photometric, and
redshift references available in NED for the object. The new page also
gives you options for displaying more data for the object, for searching
the literature for references to the object, for displaying images of
the object, for searching for the object in other databases, for changing
the cosmology input parameters, etc. Another help page accessible from
the results page has a full explanation of the results.
If you asked for an extended name search, the search will
return all of the objects in NED beginning with the name you entered.
For example, an extended name search for "NGC 4157" will return three
objects: NGC 4157 itself, and two supernovae. A summary of the data
for all of the objects is included in the search output.
Go to Name Search Input
Page.
Return to beginning of this help page.
Return to NED's Home Page.
This page allows you to search NED's master list of extragalactic
astronomical objects for entries near a named object, a given position,
or entires whose positions are compatible with an IAU-style positional name you specify.
Near Object 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
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.
If it cannot interpret the name you typed, a page will appear
with a message explaining the most likely problem with your input.
These usually fall into three categories. In all three cases, click
your browser's "Back" button to go back to the search page, and enter
another object name.
(1) If the name you entered has an
acceptable catalog name, but the object number within the catalog is
not within the range of numbers for that catalog, the page will tell
you this. An example is "M111"; there are only 110 entries in the Messier
catalog.
(2) If the catalog name itself is ambiguous, the page will list the
acceptable possibilities. An example is "A123"; this could be
"Abell 123", "Arakelian 123", "Arp 123", "Asiago1 023", or "[RC1] A1203".
(3) If the name interpreter does not recognize the catalog, the page
will sometimes suggest alternative catalogs, sometimes not. In
either case, click the "Back" button and try another name.
The input page also allows you to
- Choose a "Search Radius" (default is 1.0 arcminutes). You may choose
any radius for your search up to 300 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 only 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 (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned
sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
You may also constrain your search by redshift, object type
(see Notes on Using Object Type Constraints
for more information on object type constraints),
and name prefix
(see Notes on Excluding Objects Using Name Prefixes
for more information on using the name prefix constraint).
The default is to have no constraint of any kind.
You may reset all of the fields on the input page to their default values,
or any of the fields separately, using the several reset buttons.
Results
When a search has completed successfully, the interface opens a new page
with the object's name, position, redshift if available;
as well as counts of the bibliographic, notes, positional, photometric, and
redshift references available in NED for the object. The new page also
gives you options for displaying more data for the object, for searching
the literature for references to the object, for displaying images of
the object, for searching for the object in other databases, for changing
the cosmology input parameters, etc. Another help page accessible from
the results page has a full explanation of the results.
Near Position
NED's position interpreter recognizes
most of the standard position formats used in the literature.
Data Entry
You may specify the coordinate system you wish to use (equatorial,
ecliptic, Galactic, or supergalactic), as well as any equinox between
1500.0 and 2500.0. The defaults are "equatorial" and "J2000.0".
Type in the position around which you wish to search. There are separate
input fields for RA (or Longitude), and for Dec (or Latitude). You must
also specify a search radius which may be up to 300 arcminutes; the default
is 2.0 arcmin.
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
The input page also allows you to
- Choose a "Search Radius" (default is 2.0 arcminutes). You may choose
any radius for your search up to 300 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 only 50,000 objects with
a Near Position search.
- Choose a cosmology model.
- Constrain your search by
- Specify your output coordinate system (equatorial,
ecliptic, Galactic, or supergalactic) and its equinox (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or
J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned
sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
You may also constrain your search by redshift, object type,
(see Notes on Using Object Type Constraints
for more information on object type constraints),
and name prefix
(see Notes on Excluding Objects Using Name Prefixes
for more information on using the name prefix constraint).
The default is to have no constraint.
You may reset all of the fields on the input page to their default values,
or any of the fields separately, using the several reset buttons.
Results
When a search has completed successfully, the interface opens a new page
with the object's name, position, redshift if available;
as well as counts of the bibliographic, notes, positional, photometric, and
redshift references available in NED for the object. The new page also
gives you options for displaying more data for the object, for searching
the literature for references to the object, for displaying images of
the object, for searching for the object in other databases, for changing
the cosmology input parameters, etc. Another help page accessible from
the results page has a full explanation of the results.
By IAU-formatted Name
We have implemented two interpreters for the IAU-style positional names: 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
Enter your IAU-style name in the "IAU name:" field. 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 on the previous
line. NED has kept B1950.0 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 strict
interpretation; that is, a smaller field is searched).
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 (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or
J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned
sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
You may also constrain your search by redshift, object type
(see Notes on Using Object Type Constraints
for more information on object type constraints),
and name prefix
(see Notes on Excluding Objects Using Name Prefixes
for more information on using the name prefix constraint).
The default is to have no constraint.
You may reset all of the fields on the input page to their default values,
or any of the fields separately, using the several reset buttons.
Results
When a search has completed successfully, the interface opens a new page
with the object's name, position, redshift if available;
as well as counts of the bibliographic, notes, positional, photometric, and
redshift references available in NED for the object. The new page also
gives you options for displaying more data for the object, for searching
the literature for references to the object, for displaying images of
the object, for searching for the object in other databases, for changing
the cosmology input parameters, etc. Another help page accessible from
the results page has a full explanation of the results.
Go to Near Name or Position (Cone Search) Input
Page.
Return to beginning of this help page.
Return to NED's Home Page.
This page allows you to search NED's master list of astronomical
objects for entries constrained
- by redshift (or velocity),
- by flux density (Jy, mJy, or W m-2 Hz-1) or
magnitude,
- by object type (e.g. "RadioS", "IrS", "GPair"),
- by name prefix (e.g. "IRAS", "87GB", "UGC"), and/or
- by equatorial (J2000.0) or Galactic coordinates.
Tutorial Examples at the top of the page will set the options to do
various example searches for you. You may use these as guides for selecting
your own sample from NED, or you may set the constraints yourself.
Set your redshift constraints, if any, in z or km/sec. The
default is to have no redshift constraint.
Set your photometric constraints 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
(see Notes on Using Object Type Constraints
for more information on object type constraints),
name prefix
(see Notes on Excluding Objects Using Name Prefixes
for more information on using the name prefix constraint),
and by sky area. The default is to have no constraint.
Sky area constraints may be specified in either Equatorial 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.
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 (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or
J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned
sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
You may reset all of the fields on the input page to their default values,
or any of the fields separately, using the several reset buttons.
Before you submit your search, you must enter a token at the bottom of the
By Parameters (All-Sky) Form. This is a security measure to prevent
misuse of this form by web-bots.
Click any of the "Submit Query" buttons when you are ready to run your
search.
Beginning in September 2013, all By Parameters (All-Sky) searches will
be 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 every 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
Results" 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.
Return to the By Parameters (All-Sky) Form, click the link to the
Job Status Page
near the bottom of that form, 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, including various Text
(ASCII), HTML, and XML VOTable options. Be warned
that browser limitations may exist for particularly large HTML results
files. In this case, the query should be submitted using another output
format.
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. For HTML output,
the results page also gives you options for displaying more data for the
object, for searching the literature for references to the object, for
displaying images of the object, for searching for the object in other
databases, for changing the cosmology input parameters, etc. A help
page accessible from the results page has a full explanation of the
results.
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.
Return to beginning of this help page.
Return to NED's Home Page.
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.
Return to NED's Home Page.
This window allows you to search the master list of astronomical objects
by journal reference code (catalogs, books, and theses cannot yet be
searched using this option). There is a limit of 50,000 objects that can
be returned by this search; if NED has more than 50,000 objects from the
reference, a small window appears with that information. If the reference
has between 500 and 50,000 objects, another window appears telling you that
the search will take several minutes.
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 "19-digit reference code" box, type the full NED reference code
for the journal article you wish to search.
Reference Codes has detailed information on how references
are coded in NED.
The input page also allows you to
- Choose a cosmology model.
- Specify your output coordinate system (equatorial,
ecliptic, Galactic, or supergalactic) and its equinox (any year
between 1500.0 and 2500.0 using either Besselian or Julian dates;
default is J2000.0); use the "quick-set" buttons for B1950.0 or
J2000.0;
- Change the sort order of the returned object list (default is RA or
Longitude; options are Dec or Latitude, Galactic Longitude or Latitude,
and Increasing or Decreasing Redshift);
- Choose the format of your tabular output list
- the default, preformatted HTML text, usually displays long lists
faster; other options, which may take longer to display, include,
- an HTML table of all data for all the returned sources,
- an ASCII bar-separated variable table of the list of sources,
- an ASCII tab-separated variable table of the list of sources,
- an XML table, in VOTable format, of the list of sources,
- an XML table, in VOTable format, of the returned source names
(cross-identifications),
- an XML table, in VOTable format, of the returned source positions
(equatorial B1950 and J2000, ecliptic B1950 and J2000, Galactic,
and supergalactic)
- an XML table, in VOTable format, of the returned source quantities
derived from its redshift (if any),
- an XML table, in VOTable format, of the returned source Basic Data,
- an XML table, in VOTable format, of links to external archives
and services with data for the returned source,
- an XML table, in VOTable format, of all data for the returned
sources,
- Change the way in which redshifts are displayed (default is velocity in
km/sec below 30,000 km/sec, and dimensionless redshift above); and
- Choose how many (if any) "postage stamp" DSS image cutouts you wish to
have displayed on the results page (the default is to display up to
five images).
The image cutouts are created in real time using the
IRSA Finderchart service (POSS-II F (North),
AAO-SES/SERC-ER (South)).
You may reset all of the fields on the input page to their default values
using either of the reset buttons.
Results
When a search has completed successfully, the interface opens a new page
with the object's name, position, redshift if available;
as well as counts of the bibliographic, notes, positional, photometric, and
redshift references available in NED for the object. The new page also
gives you options for displaying more data for the object, for searching
the literature for references to the object, for displaying images of
the object, for searching for the object in other databases, for changing
the cosmology input parameters, etc. Another help page accessible from
the results page has a full explanation of the results.
If there are no NED objects with the reference code you typed, a message
to that effect appears.
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 or abstracts. 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's master list. 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.
Return to NED's Home Page.
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.
Including "ANY" object type joins highlighted 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. Including "ALL" object types joins highlighted 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".
You may also "Quick Pick" all of the "Classified Extragalactic Object
Types". This allows you to search for only those objects with physical
classifications (e.g. galaxies, galaxy clusters, QSOs) in NED;
objects included in NED as sources from a wavelength-limited catalogue (e.g.
radio sources, infrared sources, visible sources) will not be included in
your search.
Object names are 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 400:[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".
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. |
Return to beginning of this help page.
Return to NED's Home Page.
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.
Return to beginning of this help page.
Return to NED's Home Page.
