Program Interfaces

Automated access to NED's Web services using computer programs and scripts is supported. Specific sample query URLs, which can be accessed via utilities such as wget and curl or from programs written in Perl, Python or Java, can be found in NED for a New Era (Mazzarella et al. 2007). However, NED's ability to support automated access involving large data volumes or high query rates is limited. Please adhere to the NED Guidelines for Automated Queries.

Specialized NED APIs

Object Lookup

IVOA APIs

NED Simple Image Access Service (SIAv2)
Spectral Energy Distribution (SED) Service
VO Table Access Protocol (TAP) Service
NED Python Notebook Repository

See also

NASA Astronomical Virtual Observatories (NAVO)
International Virtual Observatory Alliance (IVOA)

Q: When I use a NED Form with scrollable lists of options, the default is always preset to a particular option. This forces me to exclude that option each time I use that list. Is there a way to have the list defaults in NED query pages automatically cleared of options?
A: This is the default behavior of NED (and any other Web site) when it is accessed with Internet Explorer: IE always highlights the first entry of each list it displays. If you access NED using Netscape Navigator, Firefox, Safari, or most other Web browsers, the default action is to display lists with no selections chosen. Unfortunately, this is a feature of Internet Explorer that we cannot easily program around, but we are working toward a solution.

Q: I have a list of thousands of objects which I'd like to run through NED. What is the easiest way to do this?
A: There are at least three methods that you should consider.

Another option is to submit multiple URLs via "wget", "curl", or a similar download program designed to work with URLs. NED uses the HTTP "get" protocol whenever possible with query filters and options encoded as simple URL name/value pairs in the form "&name=value". In this case, you will have to substitute a plus sign "+" for a space, and the string "%2B" for a plus sign if either of these symbols appears in a name you submit. For example, the name "SDSS J122653.91+333057.6" becomes "SDSS+J122653.91%2B333057.6". Here are some other examples.

1) Retrieve basic data for Arp 220 and display it as a bar-separated ASCII table:
http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=arp+220&extend=no&out_csys=Equatorial&out_equinox=J2000.0&of=ascii_bar

2) Search for objects within 1.0 arcmin of Arp 220, sort them by their distances from Arp 220, and display their basic data as a tab-separated ASCII table:
http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Near+Name+Search&objname=arp+220&radius=1.0&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=Distance+to+search+center&of=ascii_tab

3) Do the same 1.0-arcmin search, but from Arp 220's equatorial position for J2000.0, 15h34m57.1s, +23d30m11s:
http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Near+Position+Search&in_csys=Equatorial&in_equinox=J2000.0&lon=233.73798d&lat=23.50319d&radius=1.0&out_csys=Equatorial&out_equinox=J2000.0&of=ascii_tab

4) Retrieve photometric data for Arp 220 as a text table with bar-separated fields:
http://ned.ipac.caltech.edu/cgi-bin/datasearch?objname=arp+220&meas_type=bot&ebars_spec=ebars&label_spec=no&x_spec=freq&y_spec=Fnu_jy&xr=-1&of=ascii_bar&search_type=Photometry

Many URLs like these may be put into a file named, for example, "getNEDdata.001". "wget" can then retrieve NED's data with a command like:
wget --continue --input-file=getNEDdata.001 --output-document=NEDdata.001

Note, too, that NED's data can be formatted as XML "Virtual Observatory" tables (VOTables). The first example URL above would return NED's data in XML format by substituting "&of=ascii_bar" with "&of=xml_main":
http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=arp+220&extend=no&out_csys=Equatorial&out_equinox=J2000.0&of=xml_main

Web-based Tools NED VO Services, Chapter 18 of The National Virtual Observatory: Tools and Techniques for Astronomical Research has more examples and detailed explanations for using NED's VO services.