File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file lac_data.dat 50 1942 Lacaille's catalog of 1942 stars from [CA] obs_data.dat 56 1935 Lacaille's observations from [EA] neb_data.dat 24 42 Lacaille's nebulous objects from [EN] lac_obs_neb.dat 16 1942 Mapping between [CA], [EA], [EN] lac_notes.dat Issues in source catalogs [CA], [EA], [EN] -------------------------------------------------------------------------------- Byte-by-byte Description of file: lac_data.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- LNo [1-1942] Number in this catalog 5 A1 --- Note [+]? Warning about this entry (1) 6- 8 A3 --- Con Constellation abbreviation 9 A1 --- Inf [~]? ~ if 'informis' (2) 10- 12 A3 --- Con_ ?Second constellation abbreviation (3) 14- 16 A3 --- Let ?Letter in constellation 18- 20 A3 --- Mag Magnitude or nebulosity type (4) 22- 24 I3 deg RA.d Right ascension 1750 (degrees) 25 A1 --- Ref [*]? Reference star marker (5) 26- 27 I2 arcmin RA.m Right ascension 1750 (minutes) 29- 30 I2 arcsec RA.s Right ascension 1750 (seconds) 32- 33 I2 deg DE.d Declination south 1750 (degrees) 35- 36 I2 arcmin DE.m Declination south 1750 (minutes) 38- 39 I2 arcsec DE.s Declination south 1750 (seconds) 41- 50 A10 --- Name ?Star name -------------------------------------------------------------------------------- Note (1): a '+' here indicates a that there is an issue with this entry, with an explanation in lac_notes.dat. Note (2): this field contains the '~' character when the 'Constellationum Nomina' column indicates that the star is "informis" (outside of figure, as in Ptolemy's catalog) between two constellations, e.g., 'Inf. int. Oct. & Mens.'. In this case, the next field has the abbreviation of the second constellation. Note (3): this field contains the abbreviation of the second constellation when the 'Constellationum Nomina' column indicates that the star is either "informis" between two constellations or simply between two constellations (e.g., 'Inter Phoen. & Tucan.'). Note (4): magnitude is either an integer between 1 and 6 or one of neb "a nebulosity or remarkable whiteness in the sky, such as a faint comet would appear" ('neb.' in the catalog), En "a star surrounded or accompanied by a nebulosity" ('E neb.' in the catalog), An "a cluster of small stars close together, that appear to the naked eye as a nebulosity in the sky" ('A neb.' in the catalog), GAn "a considerable cluster of such stars" ('G.A. neb.' in the catalog), AEn "a cluster of small stars wrapped in a nebulosity" ('AE neb.' in the catalog). Note (5): Lacaille places a '*' here for stars that have been observed with maximal precision and served as reference to determine the positions of the others. -------------------------------------------------------------------------------- Byte-by-byte Description of file: obs_data.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- ONo [1-1935] Observation number 5 A1 --- Note [+]? Warning about this entry (1) 6- 8 A3 --- Con ?Constellation abbreviation 10- 12 A3 --- Let ?Letter in constellation 14- 16 A3 --- Mag Magnitude or nebulosity type (2) 18- 19 I2 h RA.h Right ascension (hours) 20 A1 --- Ref [*]? Reference star marker (3) 21- 22 I2 min RA.m Right ascension (minutes) 24- 25 I2 s RA.s Right ascension (seconds) 27- 28 I2 deg DE.d Declination south (degrees) 30- 31 I2 arcmin DE.m Declination south (minutes) 33- 34 I2 arcsec DE.s Declination south (seconds) 36- 38 A3 --- Month Month of the observation 40- 41 I2 --- Day Day of the month of the observation 43- 45 I3 --- Page ?Page number (4) 47- 56 A10 --- Name ?Star name -------------------------------------------------------------------------------- Note (1): a '+' here indicates a that there is an issue with this entry, with an explanation in lac_notes.dat. Note (2): 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 (3): reference stars have a '*' here. See Note (5) for lac_data.dat. Note (4): lines in [EA] are not numbered. The page number is mentioned for the first entry of each page to make it easier to match the observations file with the original document. -------------------------------------------------------------------------------- Byte-by-byte Description of file: neb_data.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 A3 --- Set Object class (I, II, or III) 4 A1 --- Delim [.] Delimiter 5- 6 I2 --- Num Object number within the class 8- 9 I2 h RA.h Right ascension 1750 (hours) 11- 12 I2 min RA.m Right ascension 1750 (minutes) 14- 15 I2 s RA.s Right ascension 1750 (seconds) 17- 18 I2 deg DE.d Declination south 1750 (degrees) 20- 21 I2 arcmin DE.m Declination south 1750 (minutes) 23- 24 I2 arcsec DE.s Declination south 1750 (seconds) -------------------------------------------------------------------------------- Byte-by-byte Description of file: lac_obs_neb.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- CA [1-1942] Catalog number in [CA] 5 A1 --- f_EA [x*]? Issue with observation numbering (1) 6- 9 I4 --- EA [1-1935]? Observation number in [EA] 11- 16 A6 --- NA ?Identifier in [EN] (.) -------------------------------------------------------------------------------- Note (1): 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). -------------------------------------------------------------------------------- References: [EA] M. l'Abbé de la Caille, Table des Ascensions Droites et des Déclinaisons Apparentes des Étoiles australes renfermées dans le tropique du Capricorne : observées au cap de Bonne-espérance, dans l'intervalle du 6 Août 1751, au 18 Juillet 1752. Histoire de l'Académie royale des sciences, Année 1752, pp. 539--592. Imprimerie royale, Paris, 1756. [EN] M. l'Abbé de la Caille, Sur les Étoiles Nébuleuses du Ciel Austral. Histoire de l'Académie royale des sciences, Année 1755, pp. 194--199. Imprimerie royale, Paris, 1761. [CA] Nicolas-Louis de la Caille, Coelum Australe Stelliferum seu Observationes ad Construendum Stellarum Australium Catalogum institutae, in Africa ad Caput Bonae-Spei. Guerin & Delatour, Paris, 1763. History: * 2020-09-01: new revised edition. ================================================================================