Centre de données astronomiques de Strasbourg
The Strasbourg astronomical data center (CDS) provides reference astronomical services:
- SIMBAD is the reference database for identification and bibliography of astronomical objects (outside the solar system).
- VizieR is a catalogue service for large sky surveys, catalogues and tables published in academic papers, and more and more other data associated to publications.
- The interactive sky atlas Aladin provides an interactive portal to access image collections and databases available via Virtual Observatory protocols.
- The CDS cross-match service allows to do positional cross-matching of very large catalogues.
This tutorial shows how to use the SIMBAD pointer and VizieR photometry pointer features in Aladin Desktop.
The SIMBAD pointer is a simple feature in Aladin which allows to retrieve information on an astronomical object. You can activate this feature from the Tools menu. Once activated, all you have to do is to click near an object to place the reticle on it, and wait a few seconds without moving the mouse : a query to SIMBAD will be fired, and the result is displayed as a small tooltip with basic information (object name, type and magnitude). You can click on the tooltip to get the full SIMBAD information for this object. The SIMBAD pointer result depends on the current zoom level. The most cited SIMBAD object near the clicked position is returned : if you want to have information on an object nearby one with many citations, just zoom in to click more precisely.
A related tool is the VizieR photometry pointer : once activated, it will attempt to retrieve photometric measurements from a large number of VizieR catalogues. This can work even if the object is unknown in SIMBAD. From the photometry panel, you can open the VizieR photometry webpage to get additional information. There is a shortcut icon at the bottom of the interface which lets you toggle the SIMBAD and VizieR pointers : no pointer, SIMBAD only, or SIMBAD+VizieR photometry. If you want to launch these pointers without moving the reticle, this is also possible : just right-click near an object of interest, and click on the « Explore object » option. The reticle will not move, and the SIMBAD tooltip will appear for your object.