The Washington Double Star Supplemental Catalog

(v 2024.08.12)


The Washington Double Star Supplemental Catalog (WDSS) is a database intended for large, faint duplicity surveys. This initial version only contains the 105,000-pair SDSS survey by Dhital et al. (2015 AJ 150, 57) and a handfull of smaller Gaia surveys, with additional matches of some pairs against 2MASS and other catalogs. However, it is expected to grow significantly as future data releases from Gaia, PanStarrs, etc. lead to ever-larger-scale duplicity surveys.

The WDSS has shown significant and rapid growth since the mid 2017 initial release, primarily due to Gaia DR2 and DR3. The plots below indicate the number of measures and pairs compared with the WDS: it currently has 5x as many measures and 15x as many systems.

In the rightmost figure, the number of measures per system is indicated. As shown the majority of systems have one or two measures, in most cases Gaia measures. However, a not insignificant number of systems (more than in the whole WDS!) have additional measure(s). This predominantly come from catalog matching done at USNO (2MASS, UCAC4, URAT, etc.), but almost 25,000 measures come from the work of Friedrich Damm, which we acknowledge here and for which we give our thanks.

The WDSS is also meant to be a means of testing possible new formats for the main WDS database, so the format of this catalog must be considered preliminary. The increasing number of pairs in the WDS have occasionally exposed the limitations of its current format. In particular, the WDS designation, based on arcminute-precise coordinates, has insufficient precision to give unique designations to pairs discovered in crowded fields. WDS summary lines also have insufficient space for cross-reference names for the primary, and no space for coordinates or other names for the secondary. Space is also limited for component designations, magnitudes, spectral types, and proper motions.

The initial format for the WDSS attempts to address some of these shortcomings:

  1. The system designation has been expanded from 10 to 14 characters, and is now based on the arcsecond-precise coordinates of the primary. This format is common to many other contemporary catalogs.
  2. The component field now accepts designations up to seven characters in length (e.g., the designation "Aa1,Aa2" used for a very close pair in a higher-order hierarchical systems), as opposed to the five-character limit in the WDS.
  3. Both visual and infrared magnitudes are included (with flags for data taken with filters other than the default V and K).
  4. Space has been expanded for spectral types of each component, as well as proper motions.
  5. A column has been added for parallax
  6. More space is available for alternate names for both components
  7. Space is given for precise coordinates of the secondary.

In order to accomodate this additional information, the summary line has been split into two lines. (Note that this applies only to the plain-text version of the database. An SQL-type database - not yet implemented - could of course continue to use a single summary line per pair.) An example of the WDSS format is given below. The layout is similar to that of the WDS (especially measurement lines, which are virtually identical other than the WDS-vs-WDSS designation). Detailed formats for both summary and measurements lines are given in the file wdss_format.txt. The final three columns are at present reserved for any systems or pairs found to be common to both the WDSS and the WDS. (An entry of both WDS and discoverer designation indicates a match to a WDS pair. An entry of just the WDS designation indicates the WDSS pair is an additional component to the WDS pair). Eventually these columns will provide a cross-reference between the new- and old-format WDS catalogs.

This format is by NO means "written in stone"! Suggestions for improvement are welcome from all users of the USNO double star catalogs.

----------------------------------------------------------------------------------------------------------------------------------------------------------------
wdss..........  comp1.. frst nnn th1 rho1..* vmag1* kmag1* spec1 pm1............. par1... name1................... ** coords1........... wds....... dd.....comp.
wdss..........  comp2.. last     th2 rho2..* vmag2* kmag2* spec2 pm2............. par2... name2...................    coords2...........                        
wdss.......... comps... date...... *the.... dthe.. *rho...... *dsep... *mag1..*dmag. *mag2..*dmag. filt....* tel..* nn ref..... te 
...
----------------------------------------------------------------------------------------------------------------------------------------------------------------
0000496+364648 A        1991   1 234  15.51   8.35   6.18k G5      -24.59  -22.27    6.82 TYC 2271 00911 1          V 000049.66+364648.0 00008+3647 ES  221     
0000496+364648 B        1991     234  15.51  10.31   8.82k         -25.77  -23.14    7.09 TYC 2271 01988 1            000048.62+364638.9                        
0000496+364648  AB      1991.61     234.3     .      15.51      .        8.354 0.013  10.308 0.044  530 100    0.3   1 TYC2000b Ht                              
0000496+364648  AB      1991.61        .      .        .        .        9.303 0.019  11.144 0.061  430  90    0.3   1 TYC2000b Ht                              
0000496+364648  AB      2015.0         .      .      15.38      .         .     .       .     .     673 440    0.7   1 Gai2017  Hg                              
0003431-075506 A        2009   1  61   9.67  21.21g 15.21  M2         .       .       .   SLW 0003-0755             V 000343.16-075506.1                        
0003431-075506 B        2009      61   9.67  21.48g 15.83  M2         .       .       .   2MASS J00034378-0755014     000343.74-075501.5                        
0003431-075506  AB      2009.7897    61.      .       9.67      .       22.374 0.457  22.927 0.731  355 120    2.5   1 Dhi2015  Es                        
0003431-075506  AB      2009.7897      .      .        .        .       21.206 0.048  21.480 0.061  477 280    2.5   1 Dhi2015  Es                        
0003431-075506  AB      2009.7897      .      .        .        .       19.865 0.024  20.040 0.027  623 280    2.5   1 Dhi2015  Es                        
0003431-075506  AB      2009.7897      .      .        .        .       18.648 0.013  18.829 0.014  762 300    2.5   1 Dhi2015  Es                        
0003431-075506  AB      2009.7897      .      .        .        .       18.092 0.028  18.207 0.031  913 240    2.5   1 Dhi2015  Es                        
0003431-075506 A        2009   1  92  10.08  21.21g 15.21  M2         .       .       .   SLW 0003-0755             V 000343.16-075506.1                        
0003431-075506 C        2009      92  10.08  21.52g 15.56  M2         .       .       .   2MASS J00034383-0755065     000343.84-075506.4                        
0003431-075506  AC      2009.7897    92.      .      10.08      .       22.374 0.457  26.031 0.908  355 120    2.5   1 Dhi2015  Es                        
0003431-075506  AC      2009.7897      .      .        .        .       21.206 0.048  21.521 0.063  477 280    2.5   1 Dhi2015  Es                        
0003431-075506  AC      2009.7897      .      .        .        .       19.865 0.024  19.862 0.024  623 280    2.5   1 Dhi2015  Es                        
0003431-075506  AC      2009.7897      .      .        .        .       18.648 0.013  18.667 0.013  762 300    2.5   1 Dhi2015  Es                        
0003431-075506  AC      2009.7897      .      .        .        .       18.092 0.028  18.106 0.028  913 240    2.5   1 Dhi2015  Es                        
0003431-075506 B        2009   1 163   5.16  21.48g 15.83  M2         .       .       .   2MASS J00034378-0755014     000343.74-075501.5                        
0003431-075506 C        2009     163   5.16  21.52g 15.56  M2         .       .       .   2MASS J00034383-0755065     000343.84-075506.4                        
0003431-075506  BC      2009.7897   163.      .       5.16      .       22.927 0.731  26.031 0.908  355 120    2.5   1 Dhi2015  Es                        
0003431-075506  BC      2009.7897      .      .        .        .       21.480 0.061  21.521 0.063  477 280    2.5   1 Dhi2015  Es                        
0003431-075506  BC      2009.7897      .      .        .        .       20.040 0.027  19.862 0.024  623 280    2.5   1 Dhi2015  Es                        
0003431-075506  BC      2009.7897      .      .        .        .       18.829 0.014  18.667 0.013  762 300    2.5   1 Dhi2015  Es                        
0003431-075506  BC      2009.7897      .      .        .        .       18.207 0.031  18.106 0.028  913 240    2.5   1 Dhi2015  Es                        
1018560-331253 A        1991   2 319   2.47   9.76   8.71k F7V     -82.92   -5.83    5.83 TYC 7187 01148 1          V 101856.03-331253.9 10189-3313 I   207AB   
1018560-331253 B        2015     319   2.51   9.97    .            -84.36   -4.89    5.68 TYC 7187 01148 2            101855.90-331252.0                        
1018560-331253  AB      1991.67     319.1    0.7      2.473    0.032    10.342 0.026  10.569 0.033  430  90    0.3   1 TYC2000b Ht                              
1018560-331253  AB      1991.67        .      .        .        .        9.763 0.021   9.967 0.026  530 100    0.3   1 TYC2000b Ht                              
1018560-331253  AB      2015.0         .      .       2.52      .        9.564  .      9.756  .     673 440    0.7   0 Oh_2017  Hg                              
1018560-331253  AB      2015.0      318.952  0.007    2.50725  0.00031   9.564  .      9.756  .     673 440    0.7   1 Gai2016  Hg                              
1018560-331253  AB      2015.0         .      .       2.51      .         .     .       .     .     673 440    0.7   0 Gai2017  Hg                              
1018560-331253 A        1991   2 341  98.75M  9.76   8.71k F7V     -82.92   -5.83    5.83 TYC 7187 01148 1          V 101856.03-331253.9 10189-3313             
1018560-331253 D        2015     341  98.75M 11.67  10.36j         -88.14   -5.63    5.94 TYC 7183 00703 1            101625.20-313924.9                        
1018560-331253  AD      1991.72     341.2    0.0   M 98.750    0.001    10.342 0.026  12.477 0.131  430  90    0.3   1 TYC2000b Ht                              
1018560-331253  AD      1991.72        .      .        .        .        9.763 0.021  11.667 0.086  530 100    0.3   1 TYC2000b Ht                              
1018560-331253  AD      2015.0         .      .    M 98.751     .        9.564  .     11.474  .     673 440    0.7   0 Oh_2017  Hg                              
1018560-331253  AD      2015.0      341.229  0.000 M 98.75141  0.00001   9.564  .     11.474  .     673 440    0.7   1 Gai2016  Hg                              
1018560-331253 B        1991   2 341  98.71M  9.97    .            -84.36   -4.89    5.68 TYC 7187 01148 2          V 101855.90-331252.0 10189-3313             
1018560-331253 D        2015     341  98.71M 11.67  10.36j         -88.14   -5.63    5.94 TYC 7183 00703 1            101625.20-313924.9                        
1018560-331253  BD      1991.72     341.2    0.0   M 98.711    0.001    10.569 0.033  12.477 0.131  430  90    0.3   1 TYC2000b Ht                              
1018560-331253  BD      1991.72        .      .        .        .        9.967 0.026  11.667 0.086  530 100    0.3   1 TYC2000b Ht                              
1018560-331253  BD      2015.0         .      .    M 98.712     .        9.756  .     11.474  .     673 440    0.7   0 Oh_2017  Hg                              
1018560-331253  BD      2015.0      341.239  0.000 M 98.71269  0.00001   9.756  .     11.474  .     673 440    0.7   1 Gai2016  Hg                              

The database is presently divided into 4 six-hour RA bands (wdss1.dat, ... wdss4.dat). It will undoubtedly have to be further divided into smaller bands (as in the WDS) as it grows in size. A summary file (wdss_summ.txt) is also available.

A note regarding clusters: The paper by Oh et al. (AJ 153, 2570, 2017) included many very wide pairs in systems having similar proper motion and parallax. These systems are comprised of as many as 151 components, so may more correctly be considered as moving groups rather than multiple stars. We have adopted criteria distinguishing between "clusters" (i.e., clusters, associations, or moving groups) and multiple systems, based on the number of components in the largest known physical multiples and the separations of the widest known physical binaries. If a group consists of 8 or more members and has a mean separation greater than 20,000 au, we consider it a "cluster" and its component pairs are not included in the Supplement.