SIMBAD Queries (astroquery.simbad)¶
Getting started¶
This module can be used to query the Simbad service. Presented below are
examples that illustrate the different types of queries that can be
formulated. If successful all the queries will return the results in a
Table.
A warning about big queries¶
The SIMBAD database has limited querying capacity. If you spam the server with queries, you may be temporary blacklisted. The rate limit may vary, but you should not submit more than ~5-10 queries per second.
If you want to perform large queries, we suggest using vectorized queries
when possible. You can pass query_region
a vector of coordinates or query_objects
a list of object names, and SIMBAD will treat this submission as a single
query. See vectorized queries below.
Different ways to access Simbad¶
The Simbad tool described here provides a number of convenient methods that internally creates a script query to the Simbad server, which is also how the Simbad web interface operates.
Simbad provides another way to access its database via TAP Service. This may be better suited for some usage. If you need a python client for TAP Services, check out pyvo.
Query an Identifier¶
This is useful if you want to query a known identifier. For instance to query the messier object M1:
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_object("M1")
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
------- ----------- ----------- ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
M 1 05 34 31.94 +22 00 52.2 6 6 nan nan 0 C R 2011A&A...533A..10L
Wildcards are supported. So for instance to query messier objects from 1 through 9:
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_object("m [1-9]", wildcard=True)
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
------- ----------- ----------- ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
M 1 05 34 31.94 +22 00 52.2 6 6 nan nan 0 C R 2011A&A...533A..10L
M 2 21 33 27.02 -00 49 23.7 6 6 100.000 100.000 0 C O 2010AJ....140.1830G
M 3 13 42 11.62 +28 22 38.2 6 6 200.000 200.000 0 C O 2010AJ....140.1830G
M 4 16 23 35.22 -26 31 32.7 6 6 400.000 400.000 0 C O 2010AJ....140.1830G
M 5 15 18 33.22 +02 04 51.7 6 6 nan nan 0 C O 2010AJ....140.1830G
M 6 17 40 20 -32 15.2 4 4 nan nan 0 E O 2009MNRAS.399.2146W
M 7 17 53 51 -34 47.6 4 4 nan nan 0 E O 2009MNRAS.399.2146W
M 8 18 03 37 -24 23.2 4 4 18000.000 18000.000 179 E
M 9 17 19 11.78 -18 30 58.5 6 6 nan nan 0 D 2002MNRAS.332..441F
Wildcards are supported by other queries as well - where this is the case, examples are presented to this end. The wildcards that are supported and their usage across all these queries is the same. To see the available wildcards and their functions:
>>> from astroquery.simbad import Simbad
>>> Simbad.list_wildcards()
* : Any string of characters (including an empty one)
[^0-9] : Any (one) character not in the list.
? : Any character (exactly one character)
[abc] : Exactly one character taken in the list. Can also be defined by a range of characters: [A-Z]
Query a region¶
Queries that support a cone search with a specified radius - around an identifier or given coordinates are also supported. If an identifier is used then it will be resolved to coordinates using online name resolving services available in Astropy.
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_region("m81")
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC ... COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
-------------------------- ------------- ------------- ------- -------- ... ------------- -------- -------------- -------------------
[VV2006c] J095534.0+043546 09 55 33.9854 +04 35 46.438 8 8 ... 0 B O 2009A&A...505..385A
...
When no radius is specified, the radius defaults to 20 arcmin. A radius may
also be explicitly specified - it can be entered either as a string that is
acceptable by Angle or by using
the Quantity object:
>>> from astroquery.simbad import Simbad
>>> import astropy.units as u
>>> result_table = Simbad.query_region("m81", radius=0.1 * u.deg)
>>> # another way to specify the radius.
>>> result_table = Simbad.query_region("m81", radius='0d6m0s')
>>> print(result_table)
MAIN_ID RA ... COO_BIBCODE
----------------------- ------------- ... -------------------
M 81 09 55 33.1730 ... 2004AJ....127.3587F
[SPZ2011] ML2 09 55 32.97 ... 2011ApJ...735...26S
[F88] X-5 09 55 33.32 ... 2001ApJ...554..202I
[SPZ2011] 264 09 55 32.618 ... 2011ApJ...735...26S
[SPZ2011] ML1 09 55 33.10 ... 2011ApJ...735...26S
[SPZ2011] ML3 09 55 33.99 ... 2011ApJ...735...26S
[SPZ2011] ML5 09 55 33.39 ... 2011ApJ...735...26S
[SPZ2011] ML6 09 55 32.47 ... 2011ApJ...735...26S
... ... ... ...
[MPC2001] 8 09 54 45.50 ... 2001A&A...379...90M
2MASS J09561112+6859003 09 56 11.13 ... 2003yCat.2246....0C
[PR95] 50721 09 56 36.460 ...
PSK 72 09 54 54.1 ...
PSK 353 09 56 03.7 ...
[BBC91] S02S 09 56 07.1 ...
PSK 489 09 56 36.55 ... 2003AJ....126.1286L
PSK 7 09 54 37.0 ...
If coordinates are used, then they should be entered using an astropy.coordinates.SkyCoord
object.
>>> from astroquery.simbad import Simbad
>>> import astropy.coordinates as coord
>>> result_table = Simbad.query_region(coord.SkyCoord("05h35m17.3s -05h23m28s", frame='icrs'), radius='1d0m0s')
>>> print(result_table)
MAIN_ID RA ... COO_BIBCODE
----------------------- ------------- ... -------------------
HD 38875 05 34 59.7297 ... 2007A&A...474..653V
TYC 9390-799-1 05 33 58.2222 ... 1998A&A...335L..65H
TYC 9390-646-1 05 35 02.830 ... 2000A&A...355L..27H
TYC 9390-629-1 05 35 20.419 ... 2000A&A...355L..27H
TYC 9390-857-1 05 30 58.989 ... 2000A&A...355L..27H
TYC 9390-1171-1 05 37 35.9623 ... 1998A&A...335L..65H
TYC 9390-654-1 05 35 27.395 ... 2000A&A...355L..27H
TYC 9390-656-1 05 30 43.665 ... 2000A&A...355L..27H
... ... ... ...
TYC 9373-779-1 05 11 57.788 ... 2000A&A...355L..27H
TYC 9377-513-1 05 10 43.0669 ... 1998A&A...335L..65H
TYC 9386-135-1 05 28 24.988 ... 2000A&A...355L..27H
TYC 9390-1786-1 05 56 34.801 ... 2000A&A...355L..27H
2MASS J05493730-8141270 05 49 37.30 ... 2003yCat.2246....0C
TYC 9390-157-1 05 35 55.233 ... 2000A&A...355L..27H
PKS J0557-8122 05 57 26.80 ... 2003MNRAS.342.1117M
PKS 0602-813 05 57 30.7 ...
>>> from astroquery.simbad import Simbad
>>> import astropy.coordinates as coord
>>> import astropy.units as u
>>> result_table = Simbad.query_region(coord.SkyCoord(31.0087, 14.0627,
... unit=(u.deg, u.deg), frame='galactic'),
... radius='0d0m2s')
>>> print(result_table)
MAIN_ID RA ... COO_WAVELENGTH COO_BIBCODE
------------------- ------------- ... -------------- -------------------
NAME Barnard's star 17 57 48.4980 ... O 2007A&A...474..653V
Two other options can also be specified - the epoch and the equinox. If these are not explicitly mentioned, then the epoch defaults to J2000 and the equinox to 2000.0. So here is a query with all the options utilized:
>>> from astroquery.simbad import Simbad
>>> import astropy.coordinates as coord
>>> import astropy.units as u
>>> result_table = Simbad.query_region(coord.SkyCoord(ra=11.70, dec=10.90,
... unit=(u.deg, u.deg), frame='fk5'),
... radius=0.5 * u.deg,
... epoch='B1950',
... equinox=1950)
>>> print(result_table)
MAIN_ID RA ... COO_BIBCODE
----------------------- ------------- ... -------------------
PHL 6696 00 49.4 ...
BD+10 97 00 49 25.4553 ... 2007A&A...474..653V
TYC 607-238-1 00 48 53.302 ... 2000A&A...355L..27H
PHL 2998 00 49.3 ...
2MASS J00492121+1121094 00 49 21.219 ... 2003yCat.2246....0C
TYC 607-1135-1 00 48 46.5838 ... 1998A&A...335L..65H
2MASX J00495215+1118527 00 49 52.154 ... 2006AJ....131.1163S
BD+10 98 00 50 03.4124 ... 1998A&A...335L..65H
... ... ... ...
TYC 607-971-1 00 47 38.0430 ... 1998A&A...335L..65H
TYC 607-793-1 00 50 35.545 ... 2000A&A...355L..27H
USNO-A2.0 0975-00169117 00 47 55.351 ... 2007ApJ...664...53A
TYC 607-950-1 00 50 51.875 ... 2000A&A...355L..27H
BD+10 100 00 51 15.0789 ... 1998A&A...335L..65H
TYC 608-60-1 00 51 13.314 ... 2000A&A...355L..27H
TYC 608-432-1 00 51 05.289 ... 2000A&A...355L..27H
TYC 607-418-1 00 49 09.636 ... 2000A&A...355L..27H
Query a catalogue¶
Queries can also be formulated to return all the objects from a catalogue. For instance to query the ESO catalog:
>>> from astroquery.simbad import Simbad
>>> limitedSimbad = Simbad()
>>> limitedSimbad.ROW_LIMIT = 6
>>> result_table = limitedSimbad.query_catalog('eso')
>>> print(result_table)
MAIN_ID RA ... COO_WAVELENGTH COO_BIBCODE
----------------------- ------------ ... -------------- -------------------
2MASS J08300740-4325465 08 30 07.41 ... I 2003yCat.2246....0C
NGC 2573 01 41 35.091 ... I 2006AJ....131.1163S
ESO 1-2 05 04 36.8 ... 1982ESO...C......0L
ESO 1-3 05 22 36.509 ... I 2006AJ....131.1163S
ESO 1-4 07 49 28.813 ... I 2006AJ....131.1163S
ESO 1-5 08 53 05.006 ... I 2006AJ....131.1163S
Query a bibcode¶
This retrieves the reference corresponding to a bibcode.
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_bibcode('2005A&A.430.165F')
>>> print(result_table)
References
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2005A&A...430..165F -- ?
Astron. Astrophys., 430, 165-186 (2005)
FAMAEY B., JORISSEN A., LURI X., MAYOR M., UDRY S., DEJONGHE H. and TURON C.
Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters.
Files: (abstract)
Notes: <Available at CDS: tablea1.dat notes.dat>
Wildcards can be used in these queries as well. So to retrieve all the bibcodes from a given journal in a given year:
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_bibcode('2013A&A*', wildcard=True)
>>> print(result_table)
References
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2013A&A...549A...1G -- ?
Astron. Astrophys., 549A, 1-1 (2013)
GENTILE M., COURBIN F. and MEYLAN G.
Interpolating point spread function anisotropy.
Files: (abstract) (no object)
2013A&A...549A...2L -- ?
Astron. Astrophys., 549A, 2-2 (2013)
LEE B.-C., HAN I. and PARK M.-G.
Planetary companions orbiting M giants HD 208527 and HD 220074.
Files: (abstract)
2013A&A...549A...3C -- ?
Astron. Astrophys., 549A, 3-3 (2013)
COCCATO L., MORELLI L., PIZZELLA A., CORSINI E.M., BUSON L.M. and DALLA BONTA E.
Spectroscopic evidence of distinct stellar populations in the counter-rotating stellar disks of NGC 3593 and NGC 4550.
Files: (abstract)
2013A&A...549A...4S -- ?
Astron. Astrophys., 549A, 4-4 (2013)
SCHAERER D., DE BARROS S. and SKLIAS P.
Properties of z ~ 3-6 Lyman break galaxies. I. Testing star formation histories and the SFR-mass relation with ALMA and near-IR spectroscopy.
Files: (abstract)
2013A&A...549A...5R -- ?
Astron. Astrophys., 549A, 5-5 (2013)
RYGL K.L.J., WYROWSKI F., SCHULLER F. and MENTEN K.M.
Initial phases of massive star formation in high infrared extinction clouds. II. Infall and onset of star formation.
Files: (abstract)
2013A&A...549A...6K -- ?
Astron. Astrophys., 549A, 6-6 (2013)
KAMINSKI T., SCHMIDT M.R. and MENTEN K.M.
Aluminium oxide in the optical spectrum of VY Canis Majoris.
Files: (abstract)
Query object identifiers¶
These queries can be used to retrieve all of the names (identifiers) associated with an object.
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_objectids("Polaris")
>>> print(result_table)
ID
-----------------------
NAME Polaris
NAME North Star
NAME Lodestar
PLX 299
SBC9 76
* 1 UMi
* alf UMi
AAVSO 0122+88
ADS 1477 A
AG+89 4
BD+88 8
CCDM J02319+8915A
CSI+88 8 1
FK5 907
GC 2243
GCRV 1037
...
PPM 431
ROT 3491
SAO 308
SBC7 51
SKY# 3738
TD1 835
TYC 4628-237-1
UBV 21589
UBV M 8201
V* alf UMi
PLX 299.00
WDS J02318+8916Aa,Ab
ADS 1477 AP
** WRH 39
WDS J02318+8916A
** STF 93A
2MASS J02314822+8915503
Query a bibobj¶
These queries can be used to retrieve all the objects that are contained in the article specified by the bibcode:
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_bibobj('2006AJ....131.1163S')
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC ... COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
"h:m:s" "d:m:s" ... mas deg
----------------------- ------------ ------------ ------- -------- ... ------------ ------------- -------- -------------- -------------------
M 32 00 42 41.825 +40 51 54.61 7 7 ... -- 0 B I 2006AJ....131.1163S
M 31 00 42 44.330 +41 16 07.50 7 7 ... -- 0 B I 2006AJ....131.1163S
NAME SMC 00 52 38.0 -72 48 01 5 5 ... -- 0 D O 2003A&A...412...45P
Cl Melotte 22 03 47 00 +24 07.0 4 4 ... -- 0 E O 2009MNRAS.399.2146W
2MASX J04504846-7531580 04 50 48.462 -75 31 58.08 7 7 ... -- 0 B I 2006AJ....131.1163S
NAME LMC 05 23 34.6 -69 45 22 5 5 ... -- 0 D O 2003A&A...412...45P
NAME Lockman Hole 10 45 00.0 +58 00 00 5 5 ... -- 0 E 2011ApJ...734...99H
NAME Gal Center 17 45 40.04 -29 00 28.1 6 6 ... -- 0 E
Query based on any criteria¶
Anything done in SIMBAD’s criteria interface can be done via astroquery. See that link for details of how these queries are formed.
>>> from astroquery.simbad import Simbad
>>> result = Simbad.query_criteria('region(box, GAL, 0 +0, 3d 1d)', otype='SNR')
>>> print(result)
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
--------------------- ----------- ----------- ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
EQ J174702.6-282733 17 47 02.6 -28 27 33 5 5 nan nan 0 D 2002ApJ...565.1017S
[L92] 174535.0-280410 17 48 44.4 -28 05 06 5 5 3000.000 3000.000 0 D
[GWC93] 19 17 42 04.9 -30 04 04 5 5 3000.000 3000.000 1 D
SNR G359.1-00.2 17 43 29 -29 45.9 4 4 nan nan 0 E 2000AJ....119..207L
SNR G000.1-00.2 17 48 42.5 -28 09 11 5 5 nan nan 0 D 2008ApJS..177..255L
SNR G359.9-00.9 17 45.8 -29 03 3 3 nan nan 0
SNR G359.4-00.1 17 44 37 -29 27.2 4 4 18000.000 18000.000 1 E
NAME SGR D 17 48 42 -28 01.4 4 4 18000.000 18000.000 0 E
SNR G359.1-00.5 17 45 25 -29 57.9 4 4 18000.000 18000.000 1 E
NAME SGR D SNR 17 48.7 -28 07 3 3 nan nan 0 E
Suzaku J1747-2824 17 47 00 -28 24.5 4 4 nan nan 0 E 2007ApJ...666..934C
SNR G000.4+00.2 17 46 27.65 -28 36 05.6 6 6 300.000 300.000 1 D
SNR G001.4-00.1 17 49 28.1 -27 47 45 5 5 nan nan 0 D 1999ApJ...527..172Y
GAL 000.61+00.01 17 47.0 -28 25 3 3 nan nan 0 D
SNR G000.9+00.1 17 47.3 -28 09 3 3 nan nan 0 E R 2009BASI...37...45G
SNR G000.3+00.0 17 46 14.9 -28 37 15 5 5 3000.000 3000.000 1 D
SNR G001.0-00.1 17 48.5 -28 09 3 3 nan nan 0 E R 2009BASI...37...45G
NAME SGR A EAST 17 45 47 -29 00.2 4 4 18000.000 18000.000 1 E
Vectorized Queries¶
You can query multiple regions at once using vectorized queries. Each region must have the same radius.
>>> from astroquery.simbad import Simbad
>>> import astropy.coordinates as coord
>>> import astropy.units as u
>>> result_table = Simbad.query_region(coord.SkyCoord(ra=[10, 11], dec=[10, 11],
... unit=(u.deg, u.deg), frame='fk5'),
... radius=0.1 * u.deg)
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
"h:m:s" "d:m:s" mas mas deg
------------------------- ------------- ------------- ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
PLCKECC G118.25-52.70 00 39 55.5 +10 03 42 5 5 -- -- 0 E m 2011A&A...536A...7P
IRAS 00373+0947 00 39 55.6 +10 04 15 5 5 39000.000 29000.000 67 E F 1988NASAR1190....1B
IRAS 00371+0946 00 39 43.1 +10 03 21 5 5 88000.000 32000.000 67 E F 1988NASAR1190....1B
LEDA 1387229 00 43 57.2 +10 58 54 5 5 -- -- 0 D O 2003A&A...412...45P
LEDA 1387610 00 43 50.3 +11 00 32 5 5 -- -- 0 D O 2003A&A...412...45P
LEDA 1386801 00 43 53.1 +10 56 59 5 5 -- -- 0 D O 2003A&A...412...45P
LEDA 1387466 00 43 41.3 +10 59 57 5 5 -- -- 0 D O 2003A&A...412...45P
NVSS J004420+110010 00 44 20.74 +11 00 10.8 6 6 2800.000 1200.000 90 D 1996AJ....111.1945D
SDSS J004340.18+105815.6 00 43 40.1841 +10 58 15.602 14 14 0.207 0.124 90 A O 2018yCat.1345....0G
GALEX 2675641789401008459 00 43 57.698 +10 54 46.15 7 7 -- -- 0 D 2007ApJ...664...53A
SDSS J004422.75+110104.3 00 44 22.753 +11 01 04.34 7 7 -- -- 0 C O 2017A&A...597A..79P
TYC 607-628-1 00 44 05.6169 +11 05 41.195 14 14 0.047 0.033 90 A O 2018yCat.1345....0G
You can do the same based on IDs. If you add the votable field typed_id, a
column showing your input identifier will be added:
>>> from astroquery.simbad import Simbad
>>> Simbad.add_votable_fields('typed_id')
>>> result_table = Simbad.query_objects(["M1", "M2", "M3", "M4"])
>>> print(result_table)
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE TYPED_ID
"h:m:s" "d:m:s" mas mas deg
------- ----------- ----------- ------- -------- ------------ ------------ ------------- -------- -------------- ------------------- --------
M 1 05 34 31.94 +22 00 52.2 6 6 -- -- 0 C R 2011A&A...533A..10L M1
M 2 21 33 27.02 -00 49 23.7 6 6 100.000 100.000 90 C O 2010AJ....140.1830G M2
M 3 13 42 11.62 +28 22 38.2 6 6 200.000 200.000 90 C O 2010AJ....140.1830G M3
M 4 16 23 35.22 -26 31 32.7 6 6 400.000 400.000 90 C O 2010AJ....140.1830G M4
However, note that missing data will result in missing lines:
>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_objects(["M1", "notanobject", "m2", "m1000"])
>>> print(result_table)
UserWarning: Warning: The script line number 4 raised an error (recorded in the `errors` attribute of the result table): 'notanobject': No known catalog could be found
(error.line, error.msg))
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
"h:m:s" "d:m:s" mas mas deg
------- ----------- ----------- ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
M 1 05 34 31.94 +22 00 52.2 6 6 -- -- 0 C R 2011A&A...533A..10L
M 2 21 33 27.02 -00 49 23.7 6 6 100.000 100.000 90 C O 2010AJ....140.1830G
Only the results for M1 and M2 are included. As of May 2019, there is a feature request in place with SIMBAD to return blank rows with the queried identifier indicated.
You can also stitch together region queries by writing a sophisticated script:
>>> from astroquery.simbad import Simbad
>>> script = '(region(box, GAL, 0 +0, 0.5d 0.5d) | region(box, GAL, 43.3 -0.2, 0.25d 0.25d))'
>>> result = Simbad.query_criteria(script, otype='SNR')
>>> print(result)
<Table masked=True length=4>
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE
"h:m:s" "d:m:s" mas mas deg
object str13 str13 int16 int16 float32 float32 int16 str1 str1 object
----------------- ------------ ------------ ------- -------- ------------ ------------ ------------- -------- -------------- -------------------
SNR G359.9-00.9 17 45.8 -29 03 3 3 -- -- 0
NAME Sgr A East 17 45 41 -29 00.8 4 4 -- -- 0 D 2010ApJS..188..405A
W 49b 19 11 09.000 +09 06 24.00 7 7 -- -- 0 D 2015ApJS..217....2M
SNR G000.13-00.12 17 46.4 -28 53 3 3 -- -- 0 E 2013MNRAS.434.1339H
Customizing the default settings¶
There may be times when you wish to change the defaults that have been set for the Simbad queries.
Changing the row limit¶
To fetch all the rows in the result, the row limit must be set to 0. However for some queries, results are likely to be very large, in such cases it may be best to limit the rows to a smaller number. If you want to do this only for the current python session then:
>>> from astroquery.simbad import Simbad
>>> Simbad.ROW_LIMIT = 15 # now any query fetches at most 15 rows
If you would like to make your choice persistent, then you can do this by modifying the setting in the Astroquery configuration file.
Changing the timeout¶
The timeout is the time limit in seconds for establishing connection with the Simbad server and by default it is set to 100 seconds. You may want to modify this - again you can do this at run-time if you want to adjust it only for the current session. To make it persistent, you must modify the setting in the Astroquery configuration file.
>>> from astroquery.simbad import Simbad
>>> Simbad.TIMEOUT = 60 # sets the timeout to 60s
Specifying which VOTable fields to include in the result¶
The VOTable fields that are currently returned in the result are set to
main_id and coordinates. However you can specify other fields that you
also want to be fetched in the result. To see the list of the fields:
>>> from astroquery.simbad import Simbad
>>> Simbad.list_votable_fields()
col0 col1 col2
------------------------ -------------------- --------------
bibcodelist(y1-y2) fluxdata(filtername) plx_qual
cel gcrv pm
cl.g gen pm_bibcode
coo(opt) gj pm_err_angle
coo_bibcode hbet pm_err_maja
coo_err_angle hbet1 pm_err_mina
coo_err_maja hgam pm_qual
The above shows just a small snippet of the table that is returned and has all the fields sorted lexicographically column-wise. For more information on a particular field:
>>> from astroquery.simbad import Simbad
>>> Simbad.get_field_description('ra_prec')
right ascension precision code (0:1/10deg, ..., 8: 1/1000 arcsec)
To set additional fields to be returned in the VOTable:
>>> from astroquery.simbad import Simbad
>>> customSimbad = Simbad()
# see which fields are currently set
>>> customSimbad.get_votable_fields()
['main_id', 'coordinates']
# To set other fields
>>> customSimbad.add_votable_fields('mk', 'rot', 'bibcodelist(1800-2014)')
>>> customSimbad.get_votable_fields()
['main_id', 'coordinates', 'mk', 'rot', 'bibcodelist(1800-2014')]
You can also remove a field you have set or
astroquery.simbad.SimbadClass.reset_votable_fields(). Continuing from
the above example:
>>> customSimbad.remove_votable_fields('mk', 'coordinates')
>>> customSimbad.get_votable_fields()
['main_id', 'rot', 'bibcodelist(1800-2014)']
# reset back to defaults
>>> customSimbad.reset_votable_fields()
>>> customSimbad.get_votable_fields()
['main_id', 'coordinates']
Returning the queried name in the return table¶
You can include the name(s) queried in the output table by adding typed_id to
the votable fields. This was also mentioned in vectorized queries above, but we emphasize here that it works for all queries.
>>> Simbad.add_votable_fields('typed_id')
>>> Simbad.query_objects(['M31', 'Eta Carinae', 'Alpha Centauri'])
<Table masked=True length=3>
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE TYPED_ID
"h:m:s" "d:m:s" mas mas deg
object str13 str13 int16 int16 float32 float32 int16 str1 str1 object object
--------- ------------- ------------- ------- -------- ------------ ------------ ------------- -------- -------------- ------------------- --------------
M 31 00 42 44.330 +41 16 07.50 7 7 -- -- 0 C I 2006AJ....131.1163S M31
+ eta Car 10 45 03.5455 -59 41 03.951 11 11 11.000 10.000 90 B O 2000A&A...355L..27H Eta Carinae
+ alf Cen 14 39 29.7199 -60 49 55.999 9 9 -- -- 0 C O 2016A&A...589A.115S Alpha Centauri
>>> Simbad.query_object('M31')
<Table masked=True length=1>
MAIN_ID RA DEC RA_PREC DEC_PREC COO_ERR_MAJA COO_ERR_MINA COO_ERR_ANGLE COO_QUAL COO_WAVELENGTH COO_BIBCODE TYPED_ID
"h:m:s" "d:m:s" mas mas deg
object str13 str13 int16 int16 float32 float32 int16 str1 str1 object object
------- ------------ ------------ ------- -------- ------------ ------------ ------------- -------- -------------- ------------------- --------
M 31 00 42 44.330 +41 16 07.50 7 7 -- -- 0 C I 2006AJ....131.1163S M31
Specifying the format of the included VOTable fields¶
The output for several of the VOTable fields can be formatted in many different ways described in the help page of the SIMBAD query interface (see Sect. 4.3 of this page). As an example, the epoch and equinox for the Right Ascension and Declination can be specified as follows (e.g. epoch of J2017.5 and equinox of 2000):
>>> customSimbad.add_votable_fields('ra(2;A;ICRS;J2017.5;2000)', 'dec(2;D;ICRS;J2017.5;2000)')
>>> customSimbad.remove_votable_fields('coordinates')
>>> customSimbad.query_object("HD189733")
<Table masked=True length=1>
MAIN_ID RA_2_A_ICRS_J2017_5_2000 DEC_2_D_ICRS_2017_5_2000
"h:m:s" "d:m:s"
object str13 str13
--------- ------------------------ ------------------------
HD 189733 20 00 43.7107 +22 42 39.064
Reference/API¶
astroquery.simbad Package¶
SIMBAD Query Tool¶
The SIMBAD query tool creates a script query that returns VOtable XML
data that is then parsed into a SimbadResult object. This object then
parses the data and returns a table parsed with astropy.io.votable.parse.
Classes¶
The class for querying the Simbad web service. |
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SimbadBaseQuery overloads the base query because we know that SIMBAD will sometimes blacklist users for exceeding rate limits. |
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Configuration parameters for |