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Simbad
Simbad is a database of astronomical objects (mostly of our Milky Way) and contains information on about 8 million objects. These details are shown in a common catalog. During these laboratory courses Simbad can be used to find suitable objects for N1 and N2.
Parameter search
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
find a description of all parameters and their meaning. For the laboratory courses (basically) only these are required:
- 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','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 <= 6 |
A list of different object types (for otypes
) in Simbad can be found 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.
Attention: 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 |