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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 - FILE CONTENTS ......................................... 2-1 Section 3 - FILE CHARACTERISTICS .................................. 3-1 Section 4 - REMARKS, MODIFICATIONS AND REFERENCES ................. 4-1 LIST OF TABLES TABLE 1 File Contents ................................................ 2-1 2 File Characteristics ......................................... 3-1 ii 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 from the Astronomical Data Center. Although it should enable users to read and process the data 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 - FILE 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 data is 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. File 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 right ascension (1950), but since numbering of extension, new parallaxes have removed 9419 and added two new stars: 9849, 9850 (both at R.A. (1950) = 4h 19m), The Sun (first record) has number 0. 5 --- A1 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 trigonometric 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 p.e. (parallax) < 15% "9" if p.e. (parallax) < 10% blank otherwise 12- 16 sec/yr F5.4 Annual proper motion of 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 of Dec. in arcseconds; blank if not present. See note on precision for R.A. proper motion above. 23- 27 km/sec 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/sec I4 U component of space velocity relative to Sun (blank if no data). 33- 36 km/sec I4 V component of space velocity relative to Sun (blank if no data). 37- 40 km/sec I4 W component of space velocity relative to Sun (blank if no data). 41- 45 --- F5.4 Box orbit parameter, omega, the distance of the epicenter of the box from the Galactic center (see Woolley and Candy 1968). Note that the quantities omega, 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/sec. The solar motion used is u(o)= +10 km/sec, v(o)=+10 km/sec, w(o)=+7 km/sec, while the Oort's constants adopted are A = +14.6 km/sec/kpc, B = -11.5 km/sec/kpc. For multiple systems omega, 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, m(v) or m(pg). V preferred, sometimes weighted means. Photoelectric data are given to 0.01 mag precision, M(v) and M(pg) 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 R.A. (1900) 78- 80 min F3.1 R.A. (1900) 81 --- A1 Sign of Dec. (1900) 82- 83 degrees I2 Dec. (1900) 84- 85 arcmin I2 Dec. (1900) 2-4 Table 1. (continued) Suggested Byte(s) Units Format Description 86- 87 hours I2 R.A. (1950) taken, in order of preference, from the "Smithsonian Astrophysical Observatory 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 R.A. (1950) 90- 91 sec I2 R.A. (1950) 92 --- A1 Sign of Dec. (1950) 93- 94 degrees I2 Dec. (1950) 95- 97 arcmin 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 --- A2 DM catalog designation. The HD convention of DM assignment is followed: BD north of -23 deg, CD -23 deg >= declination zone >= -52 deg, CPD south of -52 deg. 111 --- A1 Sign of DM declination zone. 112-113 --- I2 (A2) DM zone. 114-118 --- I5 (A5) DM number. DM field is entirely blank for no data. 119-123 --- I5 (A5) Number in the GCRV (Wilson 1953). Blank if not present. 2-5 Table 1. (concluded) Suggested Byte(s) Units Format Description 124-129 --- A6 Other proper-motion catalogue designations; byte 124 or bytes 124-125 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. 130-133 --- I4 (A4) YBS = HR number from "Catalogue of Bright Stars" (Hoffleit 1964). Blank for missing number. 134-136 --- 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. 137 --- 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 138 --- A1 Remarks code as above. Two bytes are used to allow for at least two remarks for the same star. 2-6 SECTION 3 - FILE 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, file density, and coding (EBCDIC, ASCII, BCD) are not included for tape copies. This information should always be supplied if secondary copies of the machine- readable catalogue are transmitted to other users or installations. Table 2. File Characteristics. Catalogue of Stars within twenty-five parsecs of the Sun. NUMBER OF FILES .................................................. 1 LOGICAL RECORD LENGTH (BYTES) ..................................... 138 RECORD FORMAT ..................................................... Fixed TOTAL NUMBER OF LOGICAL RECORDS ................................... 2150 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 137 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. 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. 4-2