V/61 Almagest (Ptolemy's Star Catalog) ================================================================================ The Almagest: Ptolemy's star catalogue Ptolemy C.: Almagest (years 127-141) Manitius K.: 1913 Jaschek C.: 1987 =1987BICDS..33..125J ================================================================================ ADC_Keywords: Historical catalog Description (from BICDS 33, 1987): This catalogue is the machine readable version of the star catalogue given by Claudius Ptolemy in his book called usually the Almagest. It is based upon its translation by K. Manitius (ed. B.G. Teubner, Leipzig 1913). The table reproduces the values given in book VII, chapter V, namely Identification, name, longitude, latitude and magnitude. To facilitate its use the following changes were made: Identifications : the numbers of Ambronn's catalogue (used by Manitius) were replaced by the numbers in the Bright Star Catalogue (D. Hoffleit and C. Jaschek - Fourth edition - Yale University Observatory 1982) which are commonly used today. Name : we have kept the Bayer names but omitted the description given by Manitius (for instance alpha UMi = that of the end of the tail). Whenever a disagreement exists concerning the identification of a given star, this is signaled by a "D" (disagreement) in the notes (last column). The list of disagreements was taken from Werner H. and Schmeidler F., "Synopsis der Nomenklatur der Fixsterne" - Wissensch. Verlags-Gesellschaft Stuttgart (1986) where the interested reader may find detailed references. Most of the disagreements stem from the work of Peters and Knobel, Washington 1915. Longitude : the Ptolomean longitudes were converted into the commonly used longitudes by adding 0 to longitudes in Aries, 30 to those in Taurus, etc. Longitudes vary thus between 0 and 360 . Latitudes : no change from Ptolemy. Magnitudes : no change from Ptolemy. Notes : "D" stands for disagreements over identifications, see above. With the publication of a computer readable version of this catalogue we hope to satisfy a long standing need. We also pay in this way our debt of gratitude toward the astronomer who produced the most used catalogue in the history of astronomy - for more than fourteen centuries it was THE catalogue by definition. It seems only appropriate that a data center, who is in a long way a descendant of such an enterprise, includes the catalogue in its collection. See also: V/50 (The Bright Star Catalogue) File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file north 47 360 Northern part (except Zodiacal stars) south 47 317 Southern part (except Zodiacal stars) zod-n 47 167 Zodiacal stars, North zod-s 47 183 Zodiacal stars, South -------------------------------------------------------------------------------- Byte-by-byte Description of file: north south zod-n zod-s -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 16 A16 --- Const Constellation name 18- 21 I4 --- HR [0/9110]? Bright Star Number, 0 if cluster 22- 24 A3 --- m_HR Second HR number for binaries 26- 27 I2 --- Seq Number in constellation 29- 31 I3 deg Lon.d Ptolemean (ecliptic) longitude (degrees) (1) 33- 34 I2 arcmin Lon.m Ptolemean (ecliptic) longitude (minutes) (1) 36 A1 --- Lat- Ptolemean (ecliptic) latitude (sign) 37- 38 I2 deg Lat.d Ptolemean (ecliptic) latitude (degrees) 40- 41 I2 arcmin Lat.m Ptolemean (ecliptic) latitude (minutes) 43- 45 F3.1 mag Mag [1/8] Ptolemean magnitude (2) 47 A1 --- Disag [D] 'D' if a disagreement exists concerning identification -------------------------------------------------------------------------------- Note (1): the Ptolomean longitudes were converted by adding 30deg in Taurus etc (see Description). The epoch of observation is compared to -128 by Grasshoff G., 1990, "The history of Ptolemy's Star Catalogue", ed. G.J. Toomer, Springer-Verlag (ISBN 0-387-97181-5) Note (2): the Ptolomean magnitudes are only integer numbers between 1 and 6; the values "7." correspond to "faint", and "8." for "nebula". The decimal value "m.3" (m between 1 and 4) indicate original "(m)-(m+1)" The decimal value "m.7" (m between 1 and 4) indicate original "(m-1)-(m)" Examples: "2.7" correspond to original "3-2" "3.3" correspond to original "3-4" Historical Notes: * 1987: Keypunched at CDS, Strasbourg; original technical note prepared by O.Yu. Malkov * 17-Jul-1995: Documentation standardized at CDS ================================================================================ (End) Francois Ochsenbein [CDS] 17-Jul-1995