IRSA Catalog Search Service
Documentation for Web Interface
Single Position Search


IRSA's Catalog Search Service allows users to search IRSA's catalogs using potentially complex constraints. The most common is a Spatial Constraint, and the simplest of these is a Single Object Search. This page describes how to specify a Single Object Search in the web version of IRSA's Catalog Search Service. You may also be interested in the following pages:

Coordinate or Object Name

Enter the name or coordinates (decimal degrees or sexigesimal format) of the center of your position search. If the input string cannot be recognized as coordinates, then it will be sent first to NED, then to SIMBAD to attempt name resolution. Examples of valid inputs include:

Search Method


A Cone Search Query allows you to search for objects that lie within a cone defined by an ellipse projected on the sky. To define this ellipse, enter the following information:

Parameter Description Required Allowed Values
Radius the radius of a circular projected search area (i.e. Axial Ratio = 1);
the semi-major axis of an elliptical projected search area (i.e. Axial Ratio < 1).
required 0 < Radius < 3600 arcsec
PA Position Angle in degrees of the semi-major axis of an elliptical projected search area, measured East from North not required default = 0
Axial Ratio semi-minor axis divided by semi-major axis for an elliptical projected search area not required Axial Ratio ≤ 1; default = 1


The Box Query returns objects that lie within a square centered on the search position. The width of the square is defined by the Size parameter, which can range from 0 < Size ≤ 7200 arcsec.


The Polygon Query returns objects that lie within a convex (no interior angles larger than 180 degrees) polygonal area defined by up to 15 vertices. Each input vertex must be entered as a J2000 RA and Dec pair, in decimal degrees. Each vertex must be separated by a comma. The first vertex does not need to be repeated.

Example: Define a search area that is a one degree wide square.

Vertices: 20.5 21.5, 20.5 20.5, 21.5 20.5, 21.5 21.5