Simbad

Simbad is a database of astronomical objects (mostly of our Milky Way) that contains information of more than 8 million objects. Simbad is an ideal tool to find suitable objects for N1 and N2.

On the mainpage of Simbad in the left column (Queries) click by criteria to find the input mask. In the section Description of the queriable fields a description of all parameters and their meaning can be found. For the laboratory courses (basically) only the following four parameters are of interest:

• sptypes
• otypes
• dec
• Vmag

A list of different object types (for otypes) in Simbad can be found here.

The parameters are entered in the text field labeled Enter a search expression. Multiple parameters are connected with an ampersand & like in this example:

dec >= 60 & sptypes ='K0' & Vmag <= 5

The output will then return all (known) objects of spectral type K0 (and its subtypes) with a visual magnitude of less equal 5mag and a declination of 60 degrees or more.

Vmag < 4 & sptypes >= F1 & sptypes <= F9 & dec > 50

This query returns stars of spectral type F1 to F9 with declination of 50 degrees or more and a visual magnitude of less than 4mag.

Attention: Before submitting the query (click Submit query) change the Return format (on the right)! The default is the object count – select display objects.

Further parameters may be useful. The OST telescope hand terminal contains the most common catalogs, so the query can be limited to objects that are in such a catalog. Also the right ascension can be useful, as the stars need to be visible during the night of the observation at the OST.