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NSSDC/WDC-A-R&S 82-03
DOCUMENTATION FOR THE MACHINE-READABLE VERSION
OF THE CATALOGUE OF STARS WITHIN 25 PARSECS
OF THE SUN
Wayne H. Warren, Jr.
January 1982
National Space Science Data Center (NSSDC)/
World Data Center A for Rockets and Satellites (WDC-A-R&S)
National Aeronautics and Space Administration
Goddard Space Flight Center
Greenbelt, MD 20771
TABLE OF CONTENTS
Section 1 - INTRODUCTION .......................................... 1-1
Section 2 - TAPE CONTENTS ......................................... 2-1
Section 3 - TAPE CHARACTERISTICS .................................. 3-1
Section 4 - REMARKS, MODIFICATIONS AND REFERENCES ................. 4-1
LIST OF TABLES
TABLE
1 Tape Contents ................................................ 2-1
2 Tape Characteristics ......................................... 3-1
iii
SECTION 1 - INTRODUCTION
"The Catalogue of Stars within twenty-five parsecs of the Sun" (Woolley, Epps,
Penston and Pocock 1970) was constructed at the Royal Greenwich Observatory in
order to enlarge the "Catalogue of Nearby Stars" compiled by Gliese (1957). The
catalogue contains data on stars nearer than 25 pc which are not included in
Gliese's catalogue, plus additional information published since 1957 on stars
in the Gliese compilation.
The machine-readable version of the "Catalogue of Stars within twenty-five
parsecs of the Sun" contains essentially all information given in Table Ia of
the published catalogue, plus positional data and all cross references to
other catalogue numbers given in Table IIa. Not included from Table Ia are
the flags (asterisks appended to catalogue numbers) indicating notes in the
published catalogue, nor are the notes in machine-readable form. Omitted from
Table IIa are the finding chart identifiers (Lowell G numbers or notes
reference) and miscellaneous cross identifications to other names and
catalogue identifiers. Tables Ib and IIb, containing 21 systems originally
included in Gliese's (1957) catalogue, but for which revised parallaxes have
placed them farther than 25 pc, are not included in the machine-readable
version. A useful extension to the present machine-readable catalogue would
be the addition of the cross identifiers and the creation of a separate file
containing the notes.
This document describes the machine-readable version of the subject catalogue
currently available on magnetic tape from the Astronomical Data Center.
Although it should enable users to read and process the tape file without
difficulty, and to interpret the data to some extent, the additional
information given in the data descriptions and the notes in the published
catalogue make it advisable to consult the latter when analyzing and/or
intepreting the data in the machine version.
SOURCE REFERENCE
Woolley, R., Epps, E. A., Penston, M. J. and Pocock, S. B. 1970, Catalogue of
Stars within twenty-five parsecs of the Sun, Roy. Obs. Ann., No. 5.
1-1
SECTION 2 - TAPE CONTENTS
A byte-to-byte description of the contents of the logical records in the
"Catalogue of Stars within twenty-five parsecs of the Sun" is given in Table 1.
The suggested format specifications are presented in order to clarify the
units and data types, and they can be modified depending upon usage; however,
care must be exercised when using integer and real format specifications in
place of character (A) formats because some data fields contain blanks when
data are absent. All tape data are recorded as integers, but real (F) format
specifications are suggested when more appropriate and to show decimal point
locations. Since data fields are blank for missing data, records should be
buffered in or fields tested in some way to distinguish between blanks and
zero. Alternate specifications are given in parentheses. For complete data
descriptions, the user should consult the published catalogue referenced on
page 1-1.
Table 1. Tape Contents. Catalogue of Stars within 25 parsecs of the Sun
Suggested
Byte(s) Units Format Description
1- 4 --- I4 Star number. Numbers in Gliese's (1957)
catalog retained; newly added stars have
numbers starting at 9001 and increasing
with RA (1950), but since numbering of
extension, new parallaxes have removed 9419
and added two new stars: 9849, 9850 (both
(both at RA (1950) = 4h 19m), The Sun (first
record) has number 0.
5 --- I1 Component identification (A, B, ...) for
stars having the same number. Stars with
separately published parallaxes have
generally been assigned separate numbers.
Components are given for extension stars
when they are known or suspected to form a
physical system.
6- 8 arcsec F3.3 Parallax. The main sources of
trigonometric parallaxes are the Yale
"General Catalogue of Trigonometric Stellar
Parallaxes" and its supplement (Jenkins
1952, 1963). Some spectroscopic parallaxes
are included and indicated by the probable
error code following.
2-1
Table 1. (continued)
Suggested
Byte(s) Units Format Description
9- 10 arcsec A2 Probable error of a trig. parallax. The two
bytes given are the least significant digits
in a number of the form +/-0.0XX which, for
pure numbers, could be read in format F2.3;
however, for spectroscopic parallax, byte 9
is blank and byte 10 contains "S".
11 --- I1 (A1) "8" if the above < 15%
"9" if the above < 10%
blank otherwise
12- 16 s/yr F5.4 Annual proper motion in R.A. in seconds
of time; blank if not present. Note that
most data are given to a precision of
0.0001 sec; however, many values are only
quoted to 0.001 sec. In the latter case,
byte 16 is blank, hence precision can be
ascertained by reading the field in an A
format and testing for a blank in byte 16.
17- 22 arcsec/yr F6.3 Annual proper motion in Dec. in arcseconds;
blank if not present. See note on
precision for RA proper motion above.
23- 27 km/s F5.1 Radial velocity taken from the GCRV (Wilson
1953), unmodified for Wilson codes a and b,
revised for codes c and d if additional
measures were available. Observed
velocities are given for white dwarfs
(uncorrected for gravitational redshift).
Additional unpublished velocities from
various observations are included where
needed. Field blank if no datum present;
if datum present, sign always in byte 23.
28 --- I1 (A1) Radial velocity code: 1 if mean value of
combined components of binary (symbol J in
published catalogue); 3 if velocity
variable (symbol V in published catalogue);
otherwise blank.
2-2
Table 1. (continued)
Suggested
Byte(s) Units Format Description
29- 32 km/s I4 U component of space velocity relative to
Sun (blank if no data).
33- 36 km/s I4 V component of space velocity relative to
Sun (blank if no data).
37- 40 km/s I4 W component of space velocity relative to
Sun (blank if no data).
41- 45 --- F5.4 Box orbit parameter, w (omega), the distance
of the epicenter of the box from the Galactic
center (see Woolley and Candy 1968). Note
that the quantities w, e and i are
normalized to the solar distance from the
Galactic center and the unit of velocity is
the Sun's circular velocity, taken to be
250 km/s. The solar motion used is u0 =
+10 km/s, v0 = +10 km/s, w0 = +7 km/s,
while the Oort's constants adopted are
A = +14.6 km/s/kpc, B = -11.5 km/s/kpc.
For multiple systems w, e and i have been
computed for the first component only using
available values of u, v, and w. Field
blank if no datum.
46- 49 --- F4.4 Box orbit parameter, e, the eccentricity of
the orbit; blank if no data.
50- 53 --- F4.4 Box orbit parameter, i, the box angle;
blank if no data.
54 --- I1 (A1) Luminosity class code (MK or Mt. Wilson):
1 - I or c; 2 - II or c; 3 - III or g;
4 - IV or sg; 5 - V or d; 6 - VI or sd;
7 - D or wd. Blank for no data. Note:
Intermediate luminosity classes have no
codes; e.g., 4 is given for class IV-V.
55- 57 --- A3 Spectral type (MK where available, mostly
from Jaschek et al. 1964; preference given
to Wilson 1953 for remaining types).
Peculiarity indicators (n, e, etc.) given
in upper case.
2-3
Table 1. (continued)
Suggested
Byte(s) Units Format Description
58 --- I1 (A1) Spectral-type code: 1 - MK; 2 - combined
MK type for multiple system; 4 - combined
non-MK; blank - non-MK.
59- 62 mag F4.2 Magnitude V, mv or mpg. V preferred,
sometimes weighted means. Photoelectric
data are given to 0.01 mag precision, Mv and
Mpg to 0.1 mag precision (byte 62 blank).
Data always present except for Sun (first
record).
63 --- I1 (A1) Magnitude code: 1 - combined light value
for multiple system (symbol J in published
catalogue); 2 - photographic magnitude (P
in published catalogue); 3 - variable
magnitude (V in published catalogue);
otherwise blank.
64- 67 mag F4.2 B-V color. Field blank if no data; sign
always in byte 64 if value present.
68- 71 mag F4.2 U-B color. Field blank if no data; sign
always in byte 68 if value present.
72- 75 mag F4.2 Absolute visual magnitude M computed from
apparent magnitude and parallax: M = m + 5
+ 5 log(parallax), reported to 0.01 mag if
both probable error of parallax < 10% and
V magnitude given to 0.01 mag.
76- 77 hours I2 Right ascension 1900
78- 80 min F3.1 R.A. 1900
81 --- A1 Sign of Declination 1900
82- 83 deg I2 Dec 1900
84- 85 arcsec I2 Dec 1900
2-4
Table 1. (continued)
Suggested
Byte(s) Units Format Description
86- 87 hours I2 RA (1950) taken, in order of preference,
from the Smithsonian Astrophysical Observ-
atory Star Catalog (SAO 1966), the lists of
Giclas et al. (1959-1969) and the General
Catalogue (GC, Boss 1937). Positions
precessed from those given in parallax
references in other cases.
88- 89 min I2 RA 1950
90- 91 sec I2 RA 1950
92 --- A1 Sign of Dec 1950
93- 94 deg I2 Dec 1950
95- 97 arcsec F3.1 Dec 1950
98-102 --- A4, A1 Number in "General Catalogue of Trigono-
metric Parallaxes" (Jenkins 1952, 1963).
For GCTP numbers form XXXX.X, the decimal
point lies between bytes 101 and 102; i.e.,
the numbers can be read with format F5.1,
but the field is blank when there is no
value given.
103-108 --- I6 (A6) "Henry Draper" (HD) catalogue number. Blank
for no data.
109-110 --- I2 (A2) DM zone. Signs are present in byte 109
only when |DMZ| < 10`; in other cases, the
sign should be taken from the declination
(byte 81 or byte 92). The HD convention of
DM assignment is followed: BD north of
-23 deg, CD -23 deg >= Dec zone >= -52 deg,
CPD south of -52 deg.
111-115 --- I5 (A5) DM number. DM field is entirely blank for
no data.
116-120 --- I5 (A5) Number in the GCRV (Wilson 1953). Blank
if not present.
2-5
Table 1. (concluded)
Suggested
Byte(s) Units Format Description
121-126 --- A6 Other proper-motion catalogue designations;
byte 121 or bytes 121-122 can contain the
following letter codes: L - Luyten LTT
catalogues (1957, 1961, 1962);
C - Cincinnati Publ. No 18 (Porter et al.
1915); CC - Cincinnati Publ. No. 20 (Porter
et al. 1930). A pure numerical designation
implies a GC number. Priority is GC, CC,
C, LTT. Field blank when no data.
127-130 --- I4 (A4) YBS = HR number from "Catalogue of Bright
Stars" (Hoffleit 1964). Blank for missing
number.
131-133 --- I3 (A3) Numbers in red-dwarf lists of Vyssotsky and
collaborators (1943, 1946, 1952, 1956) and
in supplementary list (Vyssotsky 1958).
Blank for missing data.
134 --- A1 Remarks code:
Code Abbrev.
2 SB spectroscopic binary
3 ST spectroscopic triple
4 D unresolved double,
unknown nature
5 UV UV Ceti flare star
6 EB eclipsing binary
7 SR semi-regular variable
8 AB astrometric binary
9 PL NEB planetary nebula
135 --- A1 Remarks code as above. Two bytes are used
to allow for at least two remarks for the
same star.
2-6
SECTION 3 - TAPE CHARACTERISTICS
The information contained in Table 2 is sufficient to enable a user to read
the machine version of the catalogue. Information for the entire catalog is
given in the table, but parameters which are easily varied from installation
to installation, such as block size (physical record length), blocking factor
(number of logical records per physical record), total number of blocks, tape
density, and coding (EBCDIC, ASCII, BCD, etc.) are not included. This
information should always be supplied if secondary copies of the
machine-readable catalogue are transmitted to other users or installations.
Table 2. Tape Characteristics. Catalogue of Stars within twenty-five parsecs
of the Sun.
NUMBER OF FILES .................................................. 1
LOGICAL RECORD LENGTH (BYTES) ..................................... 135
RECORD FORMAT ..................................................... FB*
TOTAL NUMBER OF LOGICAL RECORDS ................................... 2150
*Fixed length blocks
3-1
SECTION 4 - REMARKS, MODIFICATIONS AND REFERENCES
A magnetic tape version of the "Catalogue of Stars within twenty-five parsecs
of the Sun" was received from the Centre de Donnees Stellaires, Strasbourg (CDS
catalogue number 5004). As received the logical record length was 160 bytes
and the file had been recorded in O26 character code. The file was converted
to O29 code (& converted to + signs, etc.) and reformatted to eliminate all
unnecessary blank characters, thus resulting in the current 135-byte logical
record length. The remarks coding (bytes 134-135) originally included seven
codes (2-8), as defined in Table 1; however, one star (9785) in the published
catalogue (Table Ia) contains the note "PL NEB", which had not been assigned a
remarks code. The code 9 has been assigned to the planetary nebula category
and entered into byte 134 of the record for star 9785.
4-1
REFERENCES
Boss, B. 1937, General Catalogue of 33342 Stars, Publ. Carnegie Inst.,
Washington, No. 468.
Gliese W. 1957, Mitt. Astron. Rechen-Inst., Ser. A, No. 8.
Jaschek, C., Conde, H. and de Sierra, A. C. 1964, Catalogue of Stellar Spectra
Classified in the Morgan-Keenan System, Publ. La Plata Obs., Ser. Astron.
Vol. 28, No. 2.
Jenkins, L. F. 1952, General Catalogue of Trigonometric Stellar Parallaxes
(New Haven: Yale University Observatory)
Jenkins, L. F. 1963, Supplement to the General Catalogue of Trigonometric
Stellar Parallaxes (New Haven: Yale University Observatory)
Luyten, W. J. 1957, Catalogue of 9687 Stars in the Southern Hemisphere with
Proper Motions Exceeding 0.2 arcsec Annually (Minneapolis: The Lund Press).
Luyten, W. J. 1961, Catalogue of 7127 Stars in the Northern Hemisphere with
Proper Motions Exceeding 0.2 arcsec Annually (Minneapolis: The Lund Press).
Luyten, W. J. 1962, First Supplement to the LTT Catalogue (Minneapolis: Univ.
Minnesota Observatory).
Porter, J. G., Yowell, E. I. and Smith, E. 1915, Publ. Cincinnati Obs., No.
18.
Porter, J. G., Yowell, E. I. and Smith, E. 1930, Publ. Cincinnati Obs., No.
20.
Smithsonian Astrophysical Observatory. 1966, Star Catalog, Smithsonian Publ.
4652.
Vyssotsky, A. N. 1943, Astrophys. J. 97, 381.
Vyssotsky, A. N. 1956, Astrophys. J. 61, 201.
Vyssotsky, A. N. 1958, Astrophys. J. 63, 211.
Vyssotsky, A. N. and Bateer, A. M. 1952, Astrophys J. 116, 117.
Vyssotsky, A. N., Janssen, E. M., Miller, W. J. and Walther, M. E. 1946,
Astrophys. J. 104, 234.
Wilson, R. E. 1953, General Catalogue of Stellar Radial Velocities, Publ.
Carnegie Inst., Washington, No. 601.
4-2
REFERENCES (continued)
Woolley, R. v.d. R. and Candy, M. P. 1968, Mon. Not. R. Astron. Soc. 141, 277.
Woolley, R., Epps, E. A., Penston, M. J. and Pocock, S. B. 1970, Catalogue of
Stars within twenty-five parsecs of the Sun, Roy. Obs. Ann., No. 5.
4-3
