Astronomical Catalogues
The science and art of collecting
and disseminating data
Carlos E. Lopez
Universidad Nac. de San Juan, Argentina
and Yale Southern Observatory
Detectors Used in the Construction of
Astrometric Catalogues
visual + telescope
visual
1609
past
photographic
1887
CCD
1990
future
What is Astrometry?
Astrometry is that part of astronomy
dealing with the positions, motions and
trigonometric distances of celestial
objects.
What is an Astrometric Survey?
 An astrometric survey can be defined as a search
oriented to finding those celestial objects meeting a
given accuracy in their absolute or relative positions,
motions or trigonometric distances.
 Some of these surveys have been conducted with
ground-based meridian circles, astrolabes or
astrographic telescopes. Others have used or will use
space-based instrumets.
 In general, the final product of a Survey is a
Catalogue.
Astrometry’s Major Landmarks
129 BC: Hipparchus publishes the first catalogue
1609: Galileo starts to use the telescope in astronomical research
1718: Halley* introduces the concept of proper motions
1802: Herschel notes the relative orbital motion of Castor
1838: Bessel determines the trigonometric parallax of 61 Cyg
1887: The photographic plate is adopted as a detector
1989: ESA launches the Hipparcos satellite
* There is some evidence indicating that it was actually Nicholas of Cusa (circa 1400) who first mentioned the proper motion of stars
Dictionary
ASTRONOMICAL DATA:
- is the alphanumeric code that describes a parameter
or a property of a given celestial object
CATALOG / CATALOGUE:
- is a list of items, usually in a systematic order and
with a description of each.
Recycling and Evolution of the
Astronomical Data
Observation of the
Celestial Object
•Spectral Band
•Magnitude
•Spectral Type
•Variability
•Identification
•Coordinates
•Proper Motions
•Multiplicity
•Parallaxes
•Identification
General Catalogue
Distribution and Use
Detection of Errors
Comparison of Data
Crossed Identification
New Technologies
New Technologies
Two Main Different Types of Catalogues
Type
Observational Catalogue
(OC)
Description
Reports original observations made by the author
and collaborators (i.e. Bonner Durchmusterung and
the HD)
Bibliographic The data is taken from the literature and put
together following a given order. There is almost no
(BCC)
analysis of the data
Compilation
Catalogue
(CC)
Critical
(CCC)
The input data is taken from the literature. The
author makes a very careful evaluation of the data
(i.e. Yale Parallax Catalogue, General Catalogue of
Variable Stars and the SAOC)
General
(GCC)
The data is taken from the literature. The author
makes a careful evaluation of the data. Almost ALL
the available data is included (i.e. Yale Bright Star
Catalogue)
Example of OC Type:
The Henry Draper Catalogue
• 709 plates taken with the 8-inch Draper telescope
from Cambridge (Mass.)
• 1409 plates taken with a similar telescope from
Arequipa (Perú).
• 242093 stellar spectrum (artound 220000 stars)
where clasified by Annie J. Cannon between 1911
and 1915.
Example of CCC Type:
El Smithsonian Astrophysical Observatory Catalogue (SAO)
Declination Zone
Catalogue / Observatory
+90 a +85
Yale
+85 a +80
AGK2 – Greenwich AC
+80 a +60
AGK2 – AGK1
+60 a +50
Yale
+50 a +30
AGK2 – AGK1
+30 a -30
Yale
-30 a -40
CPC
-40 a -52
Cape Astrographic
-52 a -64
CPC
-64 a -90
Me3 – Me4
The Next Three Problems
Once the type of catalogue to compile has been
decided, we still have to:
 order the Catalogue
 designate each object
 designate the combination: Catalogue + Object
Possible Ways of Ordering the Data
Increasing Right Ascension for a given equinox
Increasing Right Ascension for a given equinox in
declination bands
Discovery date
Discovery date in a given spectral band
Opposition date for a given year (Solar System)
Possible Ways to Designate an Object
Name
Example
Proper Name
Sirius
Constellation
a Pav
Coordinates
1235+38 / J104842.81+011158.2
Number System
BD -16 1594, HD 48915
Number / Name following a temporal
scheme
R And, V431 Sco
Physical Characteristic
ADS 5423 / LDS 5759
Instrument Used in the Observation
4U 129
Spectral Band
Sco X-1
Nature of the Object
PSR 0011-07
Observatory
LHa
Region of the Sky
SA 16-106
Number / Name within a main object
NGC 125-7
Discoverer’s Name
Romano’s variables, Markarian’s
galaxies or Luyten’s Double Stars
Crossed Identification
HR 2491 =
HD 48915 =
BD -16 1591 =
FK4 257 =
SAO 151881 =
PPM 217626 =
GSC 5949 2777 =
HIP 32349 =
2MASS 06450887-1642566
Sirius
Sirius’ Cross ID, from SIMBAD
54 identifications
Combination Catalogue + Object
from: http://www.iee.org/Publish/Support/INSPEC/Document/Astron/index.cfm
Modifications in the designations of Objects
(as time goes by and technology changes)
1850:
1900:
1975:
1985:
1990:
visual pair is discovered
wide common proper motion companion is found
B component is found to be spectroscopy binary
C component is split by speckle interferometry
additional speckle C component is resolved at a similar
separation
1995: planet is found orbiting the A component
1998: second planet is found
2005: primary of B is resolved by long-baseline interferometry
Hartkopf, W., and Mason, B. 2004. RevMexAA (SC) 21, 83-90
Double Stars
 There is a first reference to n1 and n2 Sgr in the Almagest
 1650 The duplicity of Mizar is annouced by Riccioli
 By the end of the XVII century the duplicity of a Cen and a Cru is
announced
 1667 Montanari points out the changes in brightness of Algol
 1779 Mayer publishes the first catalogue of double stars (80 entries)
 1802 W. Herschel admits that the changes in Castor may be the
consequence of an orbital motion
 1827 Struve introduces the q and r parameters. Catalogue with 3134 pairs
 1837 first photographic observation of Mizar
Double Stars
1900 A new catalogue with 15,000 stars is published
1919 First interferometric observations by K. Schwarzschild
1921 Hertzsprung starts observations using photographic plates
1970 Speckle interferometry observations
1980 CHARA (Center for High Angular Resolution Astronomy) is formed
2002 The Tycho Double Stars Catalogue is announced by Fabricius et al.
source: WDS web page
The Washington Double Stars
Catalogue (WDS) in numbers
WDS Catalog (~12.5Mb)
00-06 hour section (~2.6Mb)
06-12 hour section (~3.6Mb)
12-18 hour section (~2.3Mb)
18-24 hour section (~4.0Mb)
Format of the current WDS
Notes file for the WDS (~1.0Mb)
References and discoverer codes (~0.7Mb)
Total 99798 systems
The “Neglected stars”
List Set I:
Northern List (Dec > +20, num = 3072)
Equatorial List (-20 < Dec < +20, num =
2331)
Southern List (Dec < -20, num = 1039)
List Set II:
Northern List (Dec > +20, num = 1860)
Equatorial List (-20 < Dec < +20, num =
2710)
Southern List (Dec < -20, num = 2062)
List Set III:
Northern List (Dec > +20, num = 21,061)
Equatorial List (-20 < Dec < +20, num =
11,491)
Southern List (Dec < -20, num = 13,216)
Total 58842 systems
WDS main (sample)
WDS (neglected stars)
The case of LDS 11 = WDS 00181-5330
N
WDS values:
q = 45º; r = 19.0” (1960)
E
Values from USNO SA2.0:
q = 75º; r = 19.0” (1996)
LDS 4023
B?
A
LDS 4023
LDS 4023
Identification of LDS systems in 2MASS and SSS(R)
(sample table)
Lopez, C., 2005 RevMexAA (SC) (in press)
Proper Motions
 1718: Halley announces the proper motion of the stars
 1775: Mayer publishes the first proper motions catalogue (998 stars)
 1783: Herschel suggests the idea of solar motion
 1887: the Astrographic Catalogue is started
 1916: Barnard discovers his famous star
 1926: Schlesinger starts the Yale Zones
 1947: Wright starts the NPM
 1950: Luyten starts to survey both hemispheres for high proper motion stars.
 1960: Giclas starts his surveys
 1965: Brower, Schill and Cesco start the SPM (YSO)
 1989: ESA launches the Hipparcos satallite
 2000: Monet announces the USNO B
Parallaxes
1580: First attempt by Tycho Brahe
1781: “…the displacement due to the parallax must be less than 1
arcsec” said James Bradley when he attempted to determine the
g Dra parallax
1837: Parallax of Vega determined by Struve
1838: Parallax of 61 Cyg determined by Bessel
1890: Publication of parallaxes for 30 stars with errors in the order of
+/-0.05 arcsec.
1903: Systematic observations with photographic plates started by
Schlesinger
1924: First edition of the YPC (~1680 star)
1935: Second edition of the YPC (~4100 stars)
Parallaxes
1952: Third edition of the YPC (~5800 stars)
1981: First parallaxes determined with CCD
1995: Fourth edition of the YPC (~8100) star
1997: Hipparcos results
2001: Henry et al. results from CTIOPI (CTIO Parallax Investigation)
many nearby stars, one of them as close as 5.5 pc.
2002: Scholz et al. present new nearby stars with d<25 pc.
2003: Teegarden et al. dicovery of a star between 2.7 and 3.6 pc
(using SkyMorph!!)
2003: Phan-Bao et al. present new stars within 25 pc (DENIS’ mining)
2005: Jao et al. present new results from the CTIOPI program
Parallaxes
Jao, W-Ch. et al. 2005 AJ. 129, 1954
before
1990
after
Number of entries in most of the astrometic catalogues
# stars << 106
# stars >> 106
The MEGA Catalogues
Over the past 15 years four catalogues -with well
over a million entries each- have been published.
They are called MEGA Catalogues:
Astrometric
 Guide Star
Catalogue (GSC)
 USNO (A and B series)
 SuperCosmos Sky Survey (SSS)
 UCAC
Non-Astrometric
 2MASS
 DENIS
 SDSS
Guide Star Catalogue (GSC): the Pioneer
 The GSC was constructed as support for the HST
 Over 19 million objects in the 6th to 15th mag. range
 Astrometry is available at the epochs of the individual plates
used in the GSC (no proper motions)
 Reference stars were selected from AGK3, SAOC, and CPC
 Extensive analysis against the Carlsberg Automatic Meridian
Circle data showed that GSC absolute positional errors from
plate center to edge vary from 0.5" to 1.1" in the north and
from 1.0" to 1.6" in the south.
 Different improvements have yielded the following realeses:
GSC I (1.0, 1.1, and 1.2)
GSC II (2.0, 2.1, 2.2, and 2.3)
Lasker, B. et al. 1990. AJ 99, 2019
Schmidt Plates in GSC I
Survey
Survey
Code
Epoch
Emulsion/Filter
Band
Depth
Dec.Zones
No.Plates
pixels
Palomar QV
N
1983-85
IIaD+W12
V
19.5
+90:+06
613
1.7"
SERC J
S
1975-87
IIIaJ+GG395
Bj
23.0
-20:-90
606
1.7"
-
SERC EJ
S
1979-88
IIIaJ+GG395
Bj
23.0
-00:-15
288
1.7"
-
SERC-QV
XV
1986-88
IIaD+GG495
V
14.0
S. Galactic
Plane
94
1"&1.7"
-
SERC-V &
PAL-V1/5
XX
1979-85
IIIa-J+GG495
V
Selected
objects
5
1.7"
-
Notes
Schmidt Plates in GSC II
Survey
Survey
Code
Epoch
Emulsion/Filter
Band
Depth
Dec.Zones
No.Plate
s
pixels
Notes
POSS-II J
XJ
1987-98
IIIaJ+GG395
Bj
22.5
+90:+00
897
1"
-
POSS-II R
XP
1987-98
IIIaF+RG610
R
20.8
+90:+00
897
1"
-
SERC J
S
1975-87
IIIaJ+GG395
Bj
23.0
-20:-90
606
1.7"
-
SERC EJ
S
1979-88
IIIaJ+GG395
Bj
23.0
-00:-15
288
1.7"
-
SERC ER
ER
1984-98
IIIaF+OG590
R
22.0
-00:-15
288
1"
-
AAO SES
XS
1990-98
IIIaF+OG590
R
22.0
-20:-90
606
1"
-
AAO-SR
GR
1996-99
IIIaF+OG590
R
20.0
S. Galactic
Plane
118
1"
-
SERC-QV
XV
1986-88
IIaD+GG495
V
14.0
S. Galactic
Plane
94
1"&1.7"
-
POSS-I E
XE
1950-58
103aE
R
20.0
+90:-30
935
1"&1.7"
Not available until
GSC 2.3
POSS-I O
XO
1950-58
103aO
B
21.0
+90:-30
935
1"
Not available until
GSC 2.3
POSS-II N
XI
1987-98
IV-N+RG9
I
19.5
+90:+00
897
1"
Not available until
GSC 2.3
SERC I
IS
1990-98
IV-N+RG715
I
19.5
-00:-90
894
1"
Not available until
GSC 2.3
Palomar QV
N
1983-85
IIaD+W12
V
19.5
+90:+06
613
1.7"
Not available until
GSC 2.3
GSPC I is an all-sky set of photoelectrically determined BV sequences in the magnitude
range from 9 to 15, generally near the centers of the fields of the GSC-I plates.
Lasker, B., Sturch, C., Lopez, C. et all. 1988, ApJS, 68, 1.
Comparison GSC 1.0 vs. CAMC (1, 2, and 3)
Taff, L. et al. 1990. ApJ 353, L45 – L48
Comparison GSC 1.0 vs. CAMC (1, 2, and 3)
Taff, L. et al. 1990. ApJ 353, L45 – L48
Comparison GSC 1.0 vs. GSC 1.2
Quick Fact Sheet on
GSC 1.1 vs. GSC 2.2
GSPC II is generally an extension of GSPC I sequences to V=19 in (B), V and R
passbands based on CCD photometry. Its purpose is the calibration of the GSC-II.
Bucciarelli, et al. A&A 368, pp 335-346, 2001
Other recentw major
astrometric catalogues
USNO-B1.0
SSS
UCAC
The USNO-B1: summary
Monet, D.; Levine, S.; Canzian, B. et al. 2003 AJ 125, 948
Number of sources: 1,045,913,669
Number of observations: 3,643,201,733
Number of plates: 7,435
Completeness down to V= 21
0.2 arcsec accuracy at J2000
0.3 mag accuracy in up to 5 colors
yes, but …
DSS frame around Hip 5164
Hip 5164
USNO B1.0 frame around Hip 5164
The Case of LDS 4023
The Case of LDS 4023
false detections
The case of VW Gru
VW Gru
d1 Gru
VW Gru (image plane) + GSC 1.2
VW Gru
d1 Gru
VW Gru (image plane) + USNO B1.0
false detections
VW Gru
d1 Gru
The case of LDS 3188
N
B
E
A
The case of LDS 3188
USNO
detection
pm according to USNO
1952.706
actual pm
1988.842
USNO B1.0 got the wrong sign!!!!
The case of LDS 3188
(comparison of proper motion)
Source
Component
pmRA
(mas)
pmDE
(mas)
USNO B1.0
A
B
-244
-144
238
410
SSS(R)
A
B
82
86
-212
-220
WDS
(Luyten)
A+B
57
-201
(astro-ph 0503512)
The SuperCosmos Sky Survey (SSS) and
The SuperCosmos Science Archive (SSA)
• The database contains over 1 billion multi-colour, multi-epoch
sources and covers the southern celestial hemisphere (d <
+3.0) in three passbands (BRI), with one colour (R) represented
at two epochs.
• All SSA global astrometry is tied to the Hipparcos-Tycho
reference frame via the Tycho-2 and ACT catalogues.
• Astrometry is globally good between 0.2 and 0.3 arcsec.
• New proper motions (with respect to the ones in SSS) have
been computed using all available positions. Up to four
different epochs have been used.
• The SSS and SSA are based on the same underlying data with
the main differences arising in the construction of the SSA
merged source table.
Plate Material
The SuperCosmos Sky Survey:
Proper Motion Comparison with the SPM
10.0<V<14.0
14.0<V<16.0
Hambly, N. C. et al. 2001. MNRAS 326, 1315.
Sample Output
DSS frame around Hip 5164
Hip 5164
SSS(R) frame around Hip 5164
14´
SSS Detections (as shown by Aladin) around Hip 5164
Object Extraction Table of SSA
The case of M50:
Comparison Between SSS and USNO B1.0
The case of M50:
Comparison Between SSS and USNO B1.0
SSS chart
The case of M50:
Comparison Between SSS and USNO B1.0
USNO B1.0
chart
The case of M50:
Missing Star in USNO B1.0?
?
Aladin
USNO B1.0 chart
The case of M50:
Missing Star in USNO B1.0 but present in 2mass and GSC 2.2
B mag
GSC 2.2 data
R mag
The UCAC Project
UCAC project goals
densification of the reference frame beyond Hipparcos/Tycho
improve accuracy of positions of faint end Tycho-2 stars
improve link between Hipparcos and the International Celestial Reference Frame
Applications
astrometric calibration of other telescopes
better reference for minor planet observations in general
allow high precision observations of NEO (Near Earth Orbit) minor planets
allow exact placement of fiber optics for spectrographic surveys
accurate astrometry for narrow field imaging, particularly for big telescopes
allow uncompromized Schmidt plate reductions
high accuracy proper motions for galactic studies
major contribution for the Space Interferometry Mission (SIM) input catalog
The UCAC2
 Positions and proper motions for over 48 million sources
(mostly stars).
 Precision on the positions is 15-70 mas (depending on
magnitude).
 Proper motions are derived by using over 140 ground- and
space-based catalogues. With errors about 1-3 mas yr-1
for stars to 12th mag., and about 4-7 mas yr-1 for fainter
stars to 16th mag.
 Current epoch positions are obtained from observations with
the USNO 8-inch Twin Astrograph equipped with a 4k CCD.
 The catalogue covers from -90º up to +48º (to +52º in some
areas) and supersedes UCAC1 released in 2001.
Differences Tycho2 – UCAC1
Zacharias, N. et al. 2000, AJ 120, 1148.
NOMAD
(Naval Observatory Merged Astrometric Database)




Astrometric and photometric data for over 1 billion stars.
Source catalogues (for astrometry and optical photometry):
Hipparcos, Tycho-2, UCAC2, and USNO-B.
Photometry supplemented by 2MASS.
NOMAD is not a compiled catalogue; that is, if a given star is
presented in more than one of the above mentioned catalogues, only
one catalogue entry is chosen.

All source catalogues astrometric data are on the ICRF.

100 GB of data.
Zacharias, N., et al. 2004b. AAS 205, 4815.
Accessing the Major Catalogues:
Data Centers and the Virtual Observatory
Some of the Astrometric Catalogues Available at CDS
The end of ADC
Working with VizieR: 4 very easy steps
http://vizier.u-strasbg.fr/viz-bin/VizieR
Step 1: open the page and …
click on …
Step 2: select the catalogue
click on the catalogue number
Step 3:
1) coord. or object
name. One may also
submit a List of
Targets.
2) Select (deselect) on
the type of data
(one may select All
Cols)
3) Select the size and
shape of the search
4) Select the output
format
5) Select the number
of lines of your
output file
Step 4: output sample
The Basic Idea
OTHERS
NTT
VLT
CFHT
HST
QUEST
GEMINI
WIYN
NGST
ESO
VIRTUAL
OBSERVATORY
Some Virtual Observatory
Initiatives
Summary of the Most Important Astrometric Catalogues
Year
Catalogue
# of Objects
360 BC
Chinese
¿?
260 BC
Aristillus & Timocharis
¿850?
129 BC
Hipparchus
850 (1,080?)
150 DC
Ptolemy’s Almagest
1,080
1277
Alfonsine Tables
¿?
1534
Ulugh-Beg
1,018
1594
Rothman & Wilhelm
1,004
Summary of the Most Important Astrometric Catalogues
Year
Catalogue
# of Objects
1601
Tycho Brahe
1,005
1661
Hevelius
1,563
1725
Flamsteed
3,310
1751
Lacaile
9,766
1760
Lalande
50,000
1792
Piazzi
7,646
1847
British Assoc.
47,390
Summary of the Most Important Astrometric Catalogues
Year
Catalogue
# of Objects
1850
Durchmusterung
300,000
1887
Astrographic Catalogue
4,000,000
1910
PGC
30,000
1926
Yale Zones
~150,000
1937
General Catalogue
33,000
1950
N30
5,000
1966
SAOC
257,997
Summary of the Most Important Astrometric Catalogues
Year
Catalogue
# of Objects
1984
FK5
1,535
1990
GSC 1.0
20,000,000
1992
4 Millions
4,000,000
1993
PPM
350,000
1996
USNO A1.0
488,000,000
1997
Hipparcos
118,218
1997
Tycho – 1
1,058,332
Summary of the Most Important Astrometric Catalogues
Year
Catalogue
# of Objects
1998
USNO A2.0
500,000,000
1998
AC2000
4,000,000
2000
GSC II
1,000,000,000
2000
Tycho – 2
2,500,000
2001
SPM
30,000,000
2002
UCAC
40,000,000
2003
USNO B1.0
1,000,000,000
Where is Astrometry?
The Next Two (Last?) Steps
Each of these missions will observe 1,000,000,000 objects !!
Recycling and Evolution of the
Astronomical Data
Observation of the
Celestial Object
•Spectral Band
•Magnitude
•Spectral Type
•Variability
•Identification
•Coordinates
•Proper Motions
•Multiplicity
•Parallaxes
•Identification
General
Catalogue
Distribution and Use
Detection of Errors
Comparison of Data
Crossed Identification
New Technologies
New Technologies
…and so I said
to myself: it’s
time to put
some order up
here !