====== Simbad ======
[[http://simbad.u-strasbg.fr/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.

===== Parameter search =====
On the mainpage of [[http://simbad.u-strasbg.fr/simbad/|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

^ Parameter      ^ Explanation       ^ Example ^
| sptype    | list all objects with the given spectral type (sptype = 'K0' -> 'K0') | sptype = 'K0'  |
| sptypes    | list all objects with the given spectral type and its subtypes (sptypes = 'k0' -> 'K0III','K0IV','K0V',...)   | sptypes = 'K0'  |
| otype    | list only objects of a given type, e.g. Cl* is stars in cluster (otype = 'Cl*' -> 'Cl*'| otype = 'Cl*'   |
| otypes    | list only objects of a given type and its subtypes (otypes = 'Cl*'  -> 'Cl*','GlC','OpCl') | otypes = Cl*   |
| dec    | Declination in degrees | dec > 60  |
| Vmag    | apparent visual brightness (magnitude) | Vmag <nowiki><=</nowiki> 6  |
A list of different object types (for ''otypes'') in Simbad can be found [[http://simbad.u-strasbg.fr/simbad/sim-display?data=otypes|here]].

===== Input =====
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.

<color red>__**Attention:**__</color> Before submitting the query (click ''Submit query'') change the ''Return'' format (on the right)! The default is the ''object count'' -- select **display objects**.

===== Furter parameters =====
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. 

^ Parameter      ^ Explanation       ^ Example ^
| cat   | list all objects that are in the given catalog | cat = 'HIP'  |
| rah   | Right ascension in hours | rah < 22.1  |