File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file ident.dat 111 2006 Identifications of Lacaille's stars dists.dat 39 2006 Differences with modern positions neb_ident.dat 65 44 Identifications of nebulous objects lacflm.dat 31 153 Cross-mapping with Flamsteed's catalog lacpia.dat 25 841 Cross-mapping with Piazzi's catalog lacref.dat 25 1974 Cross-mapping with the reference star list -------------------------------------------------------------------------------- Byte-by-byte Description of file: ident.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942]? Catalog number in [CA] (G1) 5 A1 --- f_EA [x*] Issue with observation numbering (G2) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ? Designation in [EN] (.) 17 A1 --- NoId [*] Unidentified entry flag 19- 21 A3 --- BCon ? Bayer constellation 23- 25 A3 --- BLet ? Bayer letter 27 A1 --- BInd ? Bayer index 29- 31 A3 --- FCon ? Flamsteed constellation 33- 35 I3 --- FNum [1-141]? Flamsteed number 37- 40 I4 --- HR [1-9110]? Bright Star catalog number 42- 47 I6 --- HD [1-359083]? Henry Draper catalog number 48 A1 --- addHD [*] Next HD number included 49- 54 I6 --- HIP [1-120416]? Hipparcos catalog number 56- 61 I6 --- SAO [1-258997]? SAO catalog number 62 A1 --- addSAO [*] Next SAO number included 63- 66 A4 --- Com ? Component letter(s) (3) 68- 72 F5.2 --- Mag ? Magnitude of match 73 A1 --- Shr [*] Asterisk if shared magnitude 74-111 A38 --- Name ? Deep sky object designation(s) -------------------------------------------------------------------------------- Note (3): component letter(s) from the Hipparcos or SAO catalog. -------------------------------------------------------------------------------- Byte-by-byte Description of file: dists.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942]? Catalog number in [CA] (G1) 5 A1 --- f_EA [x*] Issue with observation numbering (G2) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ? Designation in [EN] (.) 17 A1 --- NoId [*] Unidentified entry flag 18- 24 F7.2 arcmin dRA ? Difference in right ascension.cos(DE) (3) 26- 32 F7.2 arcmin dDE ? Difference in declination (3) 34- 39 F6.2 arcmin dist ? Distance between match and Lacaille (3) -------------------------------------------------------------------------------- Note (3): difference (HIP - Lacaille), or (SAO - Lacaille) if there is no HIP match. -------------------------------------------------------------------------------- Byte-by-byte Description of file: neb_ident.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 A6 --- NId ? Nebulosity id as in neb_data.dat if any 7 A1 --- Diff [-] Issue with coordinates (1) 8- 11 I4 --- ONo [1-1935] Observation number in [EA] 12 A1 --- Diff_ [-] Issue with coordinates (2) 13- 16 I4 --- LNo [1-1942]? Catalog number in [CA] if any 18- 20 A3 --- Mag Magnitude or nebulosity type (3) 21 A1 --- NoNeb [*] Issue with nebulosity type (4) 22- 28 A7 --- LacId Identification from [CA] (5) 30- 31 A2 --- Type [AS|CN|DN|GA|GC|OC]? object type (6) 33- 40 A8 --- Id Object identifier (7) 42- 65 A24 --- Name ? Object name -------------------------------------------------------------------------------- Note (1): a '-' here indicates that the coordinates given in [EN] differ from the coordinates given for the corresponding observation in [EA]. Note (2): a '-' here indicates that the coordinates given in [CA] dont' agree well with the coordinates given for the corresponding observation in [EA]. Note (3): magnitude is either an integer between 1 and 6 or one of 'neb', 'En', 'An', 'GAn', 'AEn'. See Note (4) for lac_data.dat. Note (4): a '*' here indicates that the nebulous object matches a non-nebulous entry in [EA] and [CA]. In this case, the Mag field contains a numeric magnitude instead of a nebulosity type. Note (5): the constellation(s) or constellation and letter of the catalog entry in [CA]. Note (6): modern object type abbreviation, such as AS - asterism, CN - cluster with nebula, DN - diffuse nebula, GA - galaxy, GC - globular cluster, OC - open cluster. Note (7): modern object identifier, Messier (M), NGC, IC, Trumpler (Tr), or Collinder (Cr) number. -------------------------------------------------------------------------------- Byte-by-byte Description of file: lacflm.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942]? Catalog number in [CA] (G1) 5 A1 --- f_EA [x*] Issue with observation numbering (G2) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ? Designation in [EN] (.) 18 A1 --- Status [=*] status (G3) 20- 23 I4 --- FNo [1/2936]? Unique Flamsteed star number 25- 27 A3 --- FCon ? Flamsteed constellation abbreviation 29- 31 I3 --- FNum [1/141]? Flamsteed number -------------------------------------------------------------------------------- Byte-by-byte Description of file: lacpia.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942]? Catalog number in [CA] (G1) 5 A1 --- f_EA [x*] Issue with observation numbering (G2) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ? Designation in [EN] (.) 18 A1 --- Status [=>*] status (G3) 20- 21 I2 --- ZHr [0/23]? Hour part of the Piazzi designation 22 A1 --- Dot [.] Dot delimiter 23- 25 I3 --- ZNum ? Piazzi star number within the hour -------------------------------------------------------------------------------- Byte-by-byte Description of file: lacref.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942]? Catalog number in [CA] (G1) 5 A1 --- f_EA [x*] Issue with observation numbering (G2) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ? Designation in [EN] (.) 18 A1 --- Status [=>x*] status (G3) 20- 25 I6 --- RefNo ? Number in the reference star list -------------------------------------------------------------------------------- Global notes: Note (G1): the number is missing on lines containing additional matches for the current star. Note (G2): an 'x' here marks places where the observation numbers are out of sequence, because the reduction of coordinates has caused a change in the right ascension order. A '*' here marks entries in Lacaille's catalog that don't have a corresponding entry in the observations catalog (there are 7 of them). Note (G3): status of this Lacaille object with respect to the other catalog, according to the identifications retained in ident.dat for Lacaille's catalog and ident.dat for the other catalog: = indicates that the Lacaille and other catalog entries are identified as the same object or collection of objects, > indicates that the Lacaille catalog entry includes the other catalog's entry, and more (for instance if two components of a double star are distinguished in the other catalog but lumped into one entry in this one), x indicates that the Lacaille catalog entry has an identification, but no match in the other catalog, * indicates that the Lacaille catalog entry is unidentified. -------------------------------------------------------------------------------- History: * 2026-07-13: new revised edition. ================================================================================