Reference Network

This page creates a file with a list of objects selected from one of the U.S. Naval Observatory's (USNO) astronomical catalogs. Please read and understand the Intellectual Property Rights associated with the catalog before using or distributing the catalog information.

Catalog citations are encouraged. You should check with the editor of the publication for which you are preparing your article, but the USNO suggests treating the catalog like a book, and using that sort of a format. For many publications, the following is appropriate.

Monet, D., Bird, A., Canzian, B., Harris, H., Reid, N., Rhodes, A., Sell, S., Ables, H., Dahn, C., Guetter, H., Henden, A., Leggett, S., Levison, H., Luginbuhl, C., Martini, J., Monet, A., Pier, J., Riepe, B., Stone, R., Vrba, F., Walker, R. 1996, USNO-SA2.0, (U.S. Naval Observatory, Washington DC).

In order to set reasonable limits on computer and network usage, the maximum number of selectable objects is limited to 5000. If your selection criteria select more than 5000, an error message will be returned.

USNO-A2.0 provides right ascension and declination in the system of J2000 at the mean epoch of the red and blue plates for each object. ASCII text files exist that describe each of the plates taken as part of the various surveys. Of particular interest is the epoch of each plate since proper motions have not been computed and applied to the position of each source. This information may be deciphered from Northern Plate Log or the Southern Plate Log.

Search Region Width (RA) (arcsec) Search Region Height (Decl)(arcsec) Search Region RA Center (hr min sec) Search Region Decl Center (±deg min sec)

Red mag low limit Red mag high limit Blue mag low limit Blue mag high limit Color index low limit Color index high limit

Max. surface density (objects per sq. deg.) Search region shape Sort Parameter

Sort Direction Output format Focal length (m) Pixel size (micron) Catalog

© Lowell Observatory 2008
Web Curators: Ted Bowell & Bruce Koehn
Last modified: 2008 Apr 15