Standards for Astronomical Catalogues, Version 2.0 (pdf) (February 2000)
3.1 Structure of the ReadMe File
The Description File, named ReadMe,
is aimed to provide all necessary information
to locate the catalogue (authors, title, references, summary, etc...) and to
interpret its contents by automatic procedures.
I/221 The Magellanic Catalogue of Stars - MACS (Tucholke+ 1996)
================================================================================
The Magellanic Catalogue of Stars - MACS
Tucholke H.-J., de Boer K.S., Seitter W.C.
<Astron. Astrophys. Suppl. Ser., 119, 91-98 (1996)>
<The Messenger 81, 20 (1995)>
=1996A&AS..119...91T
=1995Msngr..81...20D
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ADC_Keywords: Magellanic Clouds ; Positional data
Description:
The Magellanic Catalogue of Stars (MACS) is based on scans of ESO
Schmidt plates and contains about 244,000 stars covering large areas
around the LMC and the SMC. The limiting magnitude is B<16.5m and the
positional accuracy is better than 0.5" for 99% of the stars. The
stars of this catalogue were screened interactively to ascertain that
they are undisturbed by close neighbours.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
lmc.dat 52 175779 The Large Magellanic Cloud
smc.dat 52 67782 The Small Magellanic Cloud
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Byte-by-byte Description of file: lmc.dat smc.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- MACS Designation
14- 15 I2 h RAh Right Ascension J2000 , Epoch 1989.0 (hours)
17- 18 I2 min RAm Right Ascension J2000 (minutes)
20- 25 F6.3 s RAs Right Ascension J2000 (seconds)
27 A1 --- DE- Declination J2000 (sign)
28- 29 I2 deg DEd Declination J2000 , Epoch 1989.0 (degrees)
31- 32 I2 arcmin DEm Declination J2000 (minutes)
34- 38 F5.2 arcsec DEs Declination J2000 (seconds)
40 I1 --- Npos Number of positions used
42- 46 F5.2 mag Mag ?=99.00 Instrumental Magnitude
(to be used only in a relative sense)
48 I1 --- PosFlag [0,1] Position Flag (0: ok,
1: internal error larger than 0.5")
50 I1 --- MagFlag [0,1] Megnitude Flag (0: ok,
1: bad photometry or possible variable)
52 I1 --- BochumFlag *[0] Bochum Flag
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Note on BochumFlag: 1 if in Bochum catalog of astrophysical information
on bright LMC stars) (yet empty)
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Author's address:
Hans-Joachim Tucholke <tucholke@astro.uni-bonn.de>
================================================================================
(End) Hans-Joachim Tucholke [Univ. Bonn] 20-Nov-1995
The ReadMe file of a catalogue
An example of the ReadMe file of the catalogue I/221
is given in the ReadMe.
The description file contains severals sections; as a general rule,
only section headers are left flushed, while the text is indented
— with the noticeable exceptions of the title,
the file names in the File Summary section,
and of Note headers (section 3.5).
No line in this description file can exceed 80 characters;
it is moreover suggested to limit the textual parts to 70 characters,
such that a conversion to FITS could keep the text as COMMENT
cards.
The description file contains the following parts:
First line: catalogue designation, an abbreviated title
followed within parenthesis by the last name of the first author,
a + sign if there are multiple authors, and the year —
this information has to be condensed in a single line of 80
characters or less;
Full title(s), authors, and reference(s) of the catalogue.
Each title is left-adjusted (no indentation);
the line(s) containing the authors' names are indented
(at least two blanks), and the bibliographic
reference is enclosed between angle brackets.
The standard SIMBAD/NED/ADS 19-byte bibliographical reference
code(s) named BibCode(
see e.g.a description in the SIMBAD User's Guide, page 65,
or on the WWW page
http://cds.cds.unistra.fr/simbad/refcode.html)
is introduced by an equal sign, as a word without embedded blank
of exactly 20 characters (with the equal sign).
The Keywords.
There are three categories of keywords:
Keywords: introduces the list of keywords
as in the printed publication
ADC_Keywords introduces the list of
data-related keywords, out of a
controlled set (see also
examples at ADC). Unlike the Keywords: set
which is generally related to the scientific goal of
a paper, the ADC_Keywords are stricly related
to the tabular material collected in the paper.
Mission_Name:
for data originated from satellite mission, this
header precedes the satellite name.
Whatever the category, multiple keywords are separated by a
semicolon (;) or a dash (-) embedded in blanks.
A short description of the contents, the purpose and remarks
of special importance
of the catalogue introduced by
Description: and/or
Abstract:
section headers;
This description contains a plain ascii text; special symbols
are written with the the following conventions shared with data-base:
exponents are within carrets (^) signs, e.g.
x2+ y2 is written x^2^+y^2^, and
indices are within underscores _ like
H2O written H_2_O
special symbols can be written as text within braces,
like {delta} for δ,
{Delta} for Δ,
{+/-} for ±, {prop.to} for ∝, ...
(i.e. mostly standard LaTeX type aliases)
(optional) The list of observed objects introduced by Objects:
only in the case where no data table contains the list and position of
the astronomical objects observed or studied, as for example
in the study of a high-resolution spectrum of a single star.
Such a list is normally restricted to very few objects – less than
10 or 20 typically; when the list of objects is large, it is suggested
to store the list of objects with their positions in a dedicated
file named objects.dat or stars.dat described in a standard
way.
The structure for this list must follow the following template:
Objects:
--------------------------------------------------
RA (equinox) DE Name(s)
--------------------------------------------------
hh mm ss.s +dd mm ss Name1 = Name1
--------------------------------------------------
The header line (the one with RA, DE, and the equinox)
should be aligned with the data, in order to give a measure
of the starting byte of the object designations (names).
When each object in this list is related to a file,
the name of this file can be put within brackets at the end of
each line, as for instance in catalogue J/MNRAS/301/1031.
A list of the files making up the catalogue is introduced
by the File Summary: section header. This list includes
the following basic information for each file:
its name, its record length (length of the longest line),
the number of records, and a short title (caption).
(optional) The list of related catalogues, data sets
or services are introduced by the See also: header.
In this section, each catalog or service starts on a new line,
and is followed by a colon embedded in blanks, e.g.:
See also:
J/A+AS/97/729 : O-rich stars in 1-20um range
http://machine/description.html : Detailed Description
(optional) Due to the frequent difficulties
encountered the the nomenclature of astronomical objects,
a dedicated section introduced
by the Nomenclature Notes: header
provides the necessary explanations in the peculiar conventions
used in this matter.
A description explaining which are the columns of the
tables, how to get the values stored in these columns,
and what is their meaning is introduced by the
Byte-by-byte Description of file: section header.
This line may specify that data files include header lines
which are not part of the data
(see section 2.4);
the existence of header lines can be specified either
by a number (i.e. the first n lines of the files are not data),
or by a character which introduces a comment
(usually a hash #).
The existence of header lines is specified
in parentheses as e.g. Byte-by-byte Description (12 headlines):
or when header lines are introduced by a has sign: Byte-by-byte Description (# headlines):
The description is presented as a five-column table
with the following elements:
the starting (from 1) and ending byte of a column,
separated by a dash -;
this dash is however not required for
a single-byte column .
à la FITS format which specifies
how to interpret numbers or symbols, composed of
a letter A, I, F or E
indicating to intrepret the data as Ascii text,
Integer number, Floating-point number
with a fixed number of decimals, or a floating-point
number written in Exponential notation
followed by a number indicating the width of
the column in bytes,
eventually followed by a dot and a number
indicating the number of decimal digits
(for F and E notations)
This format could be preceded by an iteration factor
to designate an array of values all written with the
same format.
the Unit in which the value is expressed;
unit standards are detailed below (section 3.2).
The symbol — indicates unitless values,
and the square brackets [unit]
indicates values tabulated as decimal logarithmic values.
a label or column header. Standard names
and name building rules are detailed in section 3.3.
a short explanation of the contents of the column.
This last field may also specify:
a set of valid characters
for an alphabetical column, or limits for numeric columns:
see section 3.4.
(optional) Global notes — notes which apply to several
tables — are introduced by Note (Gn):n being the number of the global note referenced in the
Byte-by-byte Description of file: sections.
(optional) some other sections may exist when required, e.g.
History; introduces notes about the modification
history,
Acknowledgements: etc...
(optional) The list of references is introduced
by the References: header; the 19-character BibCode
is used when possible,
to enable an automatic link
to the existing Abstract Services like ADS.
the very last line includes just the left-flushed word
(End),
the name of the person who took care of the standardisation, and
the date of the last modification.