ii Burnham: General Catalogue of Double Stars 
PART I. CATALOGUE 
The page of the catalogue is made up of eleven columns as follows: 
Column i. General number for reference. 
Column 2. Name of the double star. When found in other catalogues the synonyms are given 
in Part II. 
Column j. Identification in the various star catalogues. Nearly all the double stars originally 
given in the several catalogues of the Herschels, the Struves, South and others, which are below the 
naked-eye limit, are not identified by the authors in any of the then existing star catalogues. So 
far as possible the stars which are bright enough to be included in any of the modern star lists 
are identified in one or another, and given in this column. 
Columns 4 and 5. Right Ascension and Declination. In the original manuscript catalogue, 
prepared more than thirty years ago, the places of the stars catalogued down to that time were 
carried forward to 1880. As the particular epoch used in a catalogue of this kind is a matter of no 
practical importance, these places have not been changed. At that time none of the catalogues of 
the Astronomische Gesettschaft had been published; otherwise the date adopted might have been 1875. 
The Durchmusterung epoch of 1855 would have served the same purpose, as no reduction is necessary, 
at least beyond a rough mental estimate, either in setting the telescope on any star in the catalogue, 
or in identifying any unknown object. 
The places of the Struve stars were originally taken from Positiones Mediae, so far as they are 
found in that catalogue, but most of them have since been checked by the more recent observations 
in the modern catalogues. The Struve stars whose positions depend upon the approximate places in 
Mensurae Micrometricae, have all been identified in the Durchmusterung and other star catalogues. This 
has been done for all the Otto Struve stars, and as far as possible for all the stars in the lists of 
Herschel, South, and other early observers. Many of the objects in the seven catalogues of Sir John 
Herschel are too faint to be given in the Durchmusterung and other meridian lists. The others have 
been identified, and the corrected places given. 
There is another class of double stars, principally from the observations of comparatively modern 
observers, where no attempt seems to have been made, beyond perhaps reading the coarse circles of 
the equatorial, to identify the star or give the exact place. As many as possible of these stars have 
been identified; others are not in or very near the given places; and still others obviously have large 
and uncertain errors of place which will make their identification hereafter a matter of accident or 
good luck. 
There seemed to be no object to be gained by giving the right ascensions any closer than the 
nearest whole second of time, since as a matter of fact a large number of these stars have a much 
greater uncertainty in place from the lack of meridian positions, and from the lack of knowledge of 
their proper motions; and to give the right ascensions to small fractions of a second would imply an 
accuracy which would be unwarranted by the material at hand. This is also true generally of the decli- 
nations. While perhaps for a greater part of the stars, the nearest tenth of a minute of arc might 
have been given, it would have had no significance in the case of several thousand stars; and in any 
event would not have made the catalogue any more useful for any conceivable purpose, practical or 
otherwise. In any investigation concerning the proper motion, or the exact place of the star, the 
original catalogues of position will of course be consulted. 
All of the stars are north of the equator, unless otherwise indicated by the minus sign attached 
to the degrees of declination. The advantage of the omission of the plus sign for the northern stars 
in rapidly finding any star, either north or south, will be apparent to those who have had to do this 
frequently in catalogues where all the signs are given. 
Columns 6 and 7. Position-angle and distance. The measures, unless otherwise noted, are 
from the original list referred to by the name of the star in column 2. For the Struve and Otto 
Struve stars the measures cited are by these observers. Nearly all the closer stars by Sir William 
Herschel are embodied in Struve's great catalogue. Those having distances exceeding the Struve 
limit, and which are not found in the later lists of Herschel II and South, are given with the 
