I/6 Cape Catalog of 20554 Faint Stars, -40 to -52° (Spencer Jones+ 1939)
Catalogue of 20554 Faint Stars in the Cape Astrographic Zone -40 to -52 Degrees
for the Equinox of 1900.0
Spencer J.H., Jackson J.
<His Majesty's Stationery Office, London (1939)>
=1939CF....C......0S 1939CF....C......0S
=1939HMSO..C......0S 1939HMSO..C......0S
ADC_Keywords: Positional data ; Proper motions
Description:
This catalog contains positions, precessions, proper motions, and
photographic magnitudes for 20,554 stars. These were derived from
photographs taken at the Royal Observatory, Cape of Good Hope between
1923 and 1928. It covers the astrographic zones -40 degrees to -52
degrees of declination. The positions are given for epoch 1900
(1900.0). It includes spectral types for many of the stars listed. It
extends the earlier catalogs derived from the same plates to fainter
magnitudes. The computer-readable version consists of a single data
table.
The stated probable error for the star positions is 0.024 seconds of
time (R.A.) and 0.25 seconds of arc (Dec.) for stars with one
determination, 0.017 seconds of time, and 0.18 seconds of arc for two
determinations, and 0.014 / 0.15 for stars with three determinations.
The precession and secular variations were derived from Newcomb's
constants.
The authors quote probable errors of the proper motions in both
coordinates of 0.008 seconds of arc for stars with one determination,
0.0055 seconds for stars with two determinations, and 0.0044 for stars
with three.
The photographic magnitudes were derived from the measured diameters
on the photographic plates and from the magnitudes given in the Cape
Photographic Durchmusterung.
The spectral classification of the catalogued stars was done with the
assistance of Annie Jump Cannon of the Harvard College Observatory.
The user should consult the source reference for more details of the
measurements and reductions. See also the notes in this document for
additional information on the interpretation of the entries.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
faint.dat 64 20554 The Catalogue
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Byte-by-byte Description of file: faint.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID Cape Number
6 A1 --- rem *[AFN] Remark
7- 9 I3 --- CPDz *? Cape Phot. Durchmusterung (CPD) Zone
10-14 I5 --- CPDno *? CPD Number or Astrographic Plate
15 I1 --- m_CPDno *[1,4]? Multiplicity Remarks
17-20 F4.1 mag mpg *?=99.9 Photographic Magnitude
21-22 I2 h RAh Mean Right Ascension hours 1900
23-24 I2 min RAm Mean Right Ascension minutes 1900
25-29 F5.2 s RAs Mean Right Ascension seconds 1900
30 A1 --- DE- [-] Declination Sign
31-32 I2 deg DEd Mean Declination degrees 1900
33-34 I2 arcmin DEm Mean Declination arcminutes 1900
35-38 F4.1 arcsec DEs Mean Declination arcseconds 1900
39 I1 --- N Number of Observations
40-44 F5.2 yr Ep-1900 Epoch +1900
45-50 F6.4 s/a pmRA ? Proper Motion in RA seconds of time
51-56 F6.3 arcsec/a pmRAas ? Proper Motion in RA arcseconds
57-62 F6.3 arcsec/a pmDE ? Proper Motion in Dec arcseconds
63-64 A2 --- Sp HD Spectral Type
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Note on rem:
A = Astrographic Star
F = Faint Proper Motion Star
N = Other Note
Note on CPDz:
All CPD Zones are negative (- sign in byte 7).
A value of "0" signifies Astrographic Plate instead of CPD.
Note on CPDno:
See also note on CPDz.
Astrographic plate listed "is the more southerly on which the
star occurs." Thus, y-coordinate is positive wherever possible.
Note on m_CPDno:
A number from 1-4 appears in this byte for double stars where
the same CPD number applies to more than one star.
Note on mpg:
The Photographic Magnitude is "determined from the CPD Magnitude
and the diameter on the Cape Astrographic Plates by means of the
data given in the volume on the Magnitudes of Stars in the Cape
Zone Catalogue."
A null value (99.9) signifies a variable star.
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History:
* Originally keypunched around 1970 (see Lederle 1971BICDS...1...25L 1971BICDS...1...25L)
* 1995-Sep: reformatted at ADC (addition of decimal points)
* 10-Jan-2011: a few spectral types fixed (detected by B. Skiff) for
CF stars 1777, 2060, 7794, 16678, 17279, 17577
References:
Spencer Jones H. and Jackson J. (1939) Catalogue of 20,554 faint stars in the
Cape Astrographic Zone -40deg to -52deg for the equinox of 1900.0
giving positions, precessions, proper motions and photographic
magnitudes (London: HMSO).
(End) Julie Anne Watko [SSDOO/ADC] 26-Mar-1996