Welcome to the USNO Flagstaff Station Integrated Image and Catalogue Archive Service

To extract a region from one of the catalogues listed below, you will need to enter the RA and Dec of the center of the region (both in DEGREES), and the radius in degrees of the search area. Verb(osity) controls the number of possible table columns returned: 1 is the least, 3 is everything in the table. Then click on the "Submit" button on the appropriate catalogue line. Data are returned in VOTable format (an XML based format agreed upon by the Virtual Observatory groups around the world).

Service Alert (30 Mar 2010: 10:10am MST): Planned service outage. The backend server will be off-line 7am-9am MST (2pm-4pm UT) on 31 March 2010 for re-location within the computer room.

Service Update (08 Dec 2009: 12:30pm MST): Added UCAC-2 and UCAC-3 The UCAC-2 and UCAC-3 catalogues have been added to the set available through this interface.

Service Update (20 Jan 2009: 8:30pm MST): Service URL change (in progress). The new URL for the interactive front-end to this service is

Service Note (20 Nov 2006 2:35pm MST): We are expecting to upgrade some of our network hardware over the course of this week (and maybe into next week). There will likely be some interruptions of this service as a result. We will try to keep the interference to a minimum.

Each of these catalogue cone-search services can be accessed directly using a GET style command. The format is

http://www.nofs.navy.mil/cgi-bin/vo_cone.cgi?CAT=USNO-B1&RA=1.0&DEC=-10.0&SR=0.1&VERB=1
   CAT  is the catalogue ID, and can be NOMAD, USNO-B1, USNO-A2, 
        UCAC-2, UCAC-3, or ACT.
   RA   is the RA in decimal degrees.
   DEC  is the DEC in decimal degrees.
   SR   is the Radius of the conesearch region in degrees.
   VERB regulates the number of fields returned for each 
        matching entry. 1 is the least, 3 is the most.

There are several optional parameters that are supported that are not specified by the VO standard. They are made available in the hope that they will provide useful additional functionality. The parameters are:

	clr = the primary selection color
        bri = Bright Magnitude limit for culling the returned catalogue
        fai = Faint Magnitude limit for culling the returned catalogue
	cftype = file type for returned data (XML/VOTable style, or ASCII)
	slf = RA/Dec formatting style
	skey = file sort key

The Faint Magnitude limit is used in determining the maximum region size that is permitted. The default maximum region A is a cone with a radius of 1.0 degrees. If the Faint Magnitude limit is SMALLER than 25.0, then the allowed region area increases in size as A*2.5^[(25-Fmag)/4]. So, if you are only interested in objects down to 12 magnitude, the allowed region area increases in size by a factor of slightly over 19, or the maximum radius increases by a bit over 4. The hard upper limit in radius is 12 degrees.