Hubble Source Catalog Search Help

This page describes how to use the Hubble Source Catalog Search form and describes the individual fields in that form.

Use this form to search the Hubble Source Catalog by object name, position, and Detection level. Other fields can also be searched using the "user-specified field" options. The Hubble Source Catalog contains information about sources detected in many of the ACS, WFPC2 and WFC3 images. The sources are detections based on combined images that are each for a particular filter, detector, and visit (Hubble Space Telescope (HST) pointing).

Please visit our Basic Hubble Source Catalog Walkthrough for step by step instructions.

Please visit our FAQ page for additional information.

Mag Type
MagType is MagAper2 or MagAuto. The default is MagAper2. Refers to magnitudes being based on either the Aper2 aperture or the Auto aperture. The actual values specify different database views. If running as a web service specify mag_type=xcat.SumMagAper2CatView for MagAper2 (or exclude it since it's the default), or set mag_type=xcat.SumMagAutoCatView for MagAuto.

Number of Images
Number of HLA level 2 images for the match (i.e., the value of matchID). For the web search interface the default value for Numimages is "> 1". This removes objects with only one detection (generally cosmic rays that have slipped in).