/ftp/cats/iv/18



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IV/18               WDS-DM-HD-ADS Cross Index             (Roman 1987)
The following files can be converted to FITS (extension .fit .fiz or .fiZ)
	position.dat namesort.dat dmsort.dat hdsort.dat adssort.dat
	namedup.dat
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Query from: http://vizier.u-strasbg.fr/cgi-bin/VizieR?-source=IV/18
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drwxr-xr-x 36 cats archive 4096 Jan 27 2020 [Up] drwxr-xr-x 2 cats archive 4096 May 26 16:19 [TAR file] -rw-r--r-- 1 cats archive 513 Mar 6 1998 .message -r--r--r-- 1 cats archive 23500 Aug 23 2000 ReadMe -r--r--r-- 1 cats archive 265072 Apr 3 1997 adssort.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 609429 May 2 1991 dmsort.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 380530 May 2 1991 hdsort.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 33277 Apr 3 1997 namedup.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 796507 May 2 1991 namesort.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html] -r--r--r-- 1 cats archive 1018089 Apr 3 1997 position.dat.gz [txt] [txt.gz] [fits] [fits.gz] [html]
Beginning of ReadMe : IV/18 WDS-DM-HD-ADS Cross Index (Roman 1987) ================================================================================ WDS-DM-HD-ADS Cross Index Roman N. G. <Astronomical Data Center (1987)> ================================================================================ ADC_Keywords: Stars, double and multiple ; Cross identifications Abstract: A cross index of 1900 positions and discoverer names, DM numbers, HD numbers, and ADS numbers has been prepared for stars in the 1984 tape version of the Washington Catalog of Visual Double Stars (WDS). Five files are furnished so that any of these designations can be used to search the cross index. A file of discoverer names and numbers is included in the catalog for systems with multiple designations. All DM numbers given in the notes to the WDS have been transferred to the cross index, and many additional or corrected DM numbers have been inserted. Year 2000 positions are also given in the sort by 1900 positions. Errors Detected: Note that many of the positions in the 1900 declination range +/-1deg are in error. Introduction: A machine-readable version of the Washington Catalog of Visual Double Stars (WDS) was prepared in 1984 (Worley 1984) on the basis of a data file that has been collected and maintained for more than a century by a succession of double-star observers. Although this catalog is now being continually updated, a new copy for distribution is not expected to be available for a few years. The WDS contains DM numbers (Argelander 1859-1862, Gill and Kapteyn 1895-1900, Thome 1892-1932), but many of these are listed only in the notes, which makes it difficult to search for double-star information, except by position. Hence, a cross index that provides complete DM identifications is desirable, and it appears useful to add HD numbers (Cannon and Pickering 1918-1924, Cannon 1925- 1936) for systems in that catalog. Aitken Double Star (ADS) numbers (Aitken 1932) have been retained from the WDS, but no attempt has been made to correct these except for obvious errors. A major effort in the preparation of this cross index has been devoted to improving the DM designations. A subset of the information in the WDS has been prepared that lists the 1900 position, the double-star observer and number, the component designation, the DM number, and the ADS number. All DM numbers given only in the notes have been entered by duplicating the entry and changing the component designation appropriately. The standard rule for multiple systems in the catalog is that the DM number refers to the first component. This rule is frequently violated, however, so that it often appears that a single component has two different DM numbers. All such cases have been checked and the component designations have been corrected appropriately. It should be noted that the introduction to the 1984 machine-readable version of the WDS is in error: unless modified by the notes, DM numbers for the -52d zone refer to the CPD. In multiple systems with more than one discoverer name, numbers are sometimes given for components with one name and not for components with another, even though the magnitudes and spectral types indicate that the entries refer to the same star. In those cases in which the stars are well above the magnitude limit of the Durchmusterung (usually brighter than ninth magnitude), the DM catalog was searched for other stars that might be confused with the star identified in the WDS. If no such star was found, the DM number was entered for the second name as well. As part of the preparation for the HIPPARCOS project, a significant number of DM numbers has been found for WDS stars by position matches (Nys 1983; Bacchus 1983; Nys 1983; Bacchus and Nys 1985; Nys 1984). Many fainter components were located in the Cape Photographic Dtuchmusterung (CP) for systems north of -52d declination for which the brighter component is in the Cordoba Dllrchmusterung (CD). These DM assignments were also checked as far as possible, and most are included in the cross index. In the course of various checks, other errors were uncovered. Many, but by no means all of these, involved either supplemental stars in the northern hemisphere (Warren and Kress 1980) or catalog confusion in the southern hemisphere. To alleviate the latter problem in the future, catalog designations have been added for all DM numbers. Appendix B (on microfiche) lists all DM numbers that have been newly entered or changed from those in the WDS. Numbers given correctly in the notes to the WDS are not included. Using the improved DM listing, a correlation between a DM sort of the WDS and a DM sort of the HD was used to insert HD numbers for the appropriate systems. Stars for which WDS and HD listings differed in position by more than 3 minutes of arc in declination or 0.3 minutes of time in right ascension were investigated individually, often leading to the discovery of errors, which were corrected. The stars without DM numbers were then correlated with the HD by position, and the HD numbers were inserted if the magnitudes and spectral types agreed satisfactorily. For most of the position matches, the stars are sufficiently close to the magnitude limit of the HD, or the HD positions in crowded fields are sufficiently rough, that it is impossible to verify that the same star is referenced. For the few cases in which the identity appears highly likely, the HD number and, occasionally, the DM number from the HD have been added to the cross index. All position matches with the HD for WDS stars without DM numbers are listed in nodm.dat. For the WDS entries, table 8 gives the 1900 position, the discoverer name and number, and the magnitudes as given in the WDS; the HD data provided are the HD and DM numbers, the position, the visual magnitude, and the spectral type. If the HD does not give a visual magnitude, the photographic magnitude is given in italics. It proved impossible to resolve a few of the problems uncovered. These are listed in Table 1. In other cases, the resolution may not have been obvious, but a reasonably likely resolution was adopted. Care should be taken with multiple systems with two or more observer identifications. The WDS is not completely consistent either in assigning DM numbers to relatively bright stars or in assigning DM numbers to components in more than one subsystem. The proper DM number for the component, the DM number for the brightest component, or no DM number may be listed. An attempt has been made to clarify the assignment of the DM numbers when it appears likely that the same star is involved and no DM number is listed. Only in extreme cases have DM numbers been removed for components that are too faint to be in the DM catalogs. Although an attempt was made to assign the proper DM number to each component, there were some circumstances in which this was not done. If the magnitude of a component is ninth or fainter, if no magnitude is given in the WDS, or if there are several stars in the vicinity with approximately the same magnitude, the proper assignment is uncertain. In many systems a DM number is given for a secondary component, but it is apparent from the magnitudes that the number refers to the brightest component of the subsystem. If the primary of the subsystem is not included in the WDS for the same subsystem name, both the component designation and the DM number are retained as given in the WDS unless it is reasonably certain that the star is the same as that in another subsystem with a different DM number. Near the limit of the DM catalogs, especially, many components listed without DM numbers are probably actually DM stars. As for the DM numbers, HD numbers have been assigned to components listed in more than one subsystem when it appears likely that the same star is involved. However, particularly with HD numbers, it is often difficult to determine whether two stars with the same DM number really are the same star. names.dat lists all systems with multiple discoverer names and numbers, with all designations occurring in the system. It is sorted alphabetically and, within a discoverer designation, numerically. The systems are listed multiply so that the list may be entered with any designation. An attempt has also been made to assign HD numbers to the proper components when two HD numbers refer to the same DM number, but this is often impossible. In many cases, the assignment of two numbers in the HD is merely an indication that the spectrum is composite, and the assignment of the numbers to individual components is meaningless. Nevertheless, an assignment for at least one discoverer designation in a system is made to alert the catalog user to the existence of two numbers in the HD. In assigning HD numbers to components, the following criteria were used in descending order of priority: (1) the relative position, in the few cases in which the HD lists different positions; (2) spectral type; (3) magnitude; and (4) position angle (that is, the earlier HD number is presumed to be the western component, although in many cases it is clear that the HD could not distinguish which component is the western one). Table 2 lists multiple HD numbers for systems with the same DM number which are not given in the Cross Index. All changes in the cross index other than those in the DM number are listed in Table 3. The references for the changes listed in the column headed "S" of Appendix B and Table 3 are as follows: 1. Abt, H. A. 1978, private communication. 2. Nys, O. 1983, Bull. Inform. CDS No. 24, p. 53. 3. Bacchus, P. 1983, Bull. Inform. CDS No. 25, p. 23. 4. Nys, O. 1983, Bull. Inform. CDS No. 25, p. 27. 5. Bacchus, P. and Nys, O. 1985, Bull. Inform. CDS No. 29, p. 43. 6. Nys, O. 1984, Bull. Inform. CDS No. 26, p. 53. 7. ADC. 8. ADC, confirmed in updated WDS file (Worley, private communication). Note that many other Changes attributed to the ADC are also included in the updated WDS, but these have not been checked. For the most part, if a component had a letter designation in the WDS, this is retained to alert the cross index user to the fact that the system may have more than two components. If a DM number is listed in the notes for B in a two-component system, A has been added for the primary component to distinguish between A and B. The revision of the WDS currently in progress replaces the 1900 positions by J2000 positions. To facilitate the use of this cross index at a later date, equinox 2000 positions are also included in 2000.dat. They may not agree exactly with the new catalog positions, since proper motions are not applied; but, except for systems with very high proper motions, they should allow the user to locate the systems in the newer catalog. Five stars in the WDS have no discoverer designations. Worley has since provided "names" for these systems. These are listed in Table 4 and are included in the cross index.

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