I/34 Second Greenwich Catalog of Stars for 1925.0 (London 1935)
Second Greenwich Catalog of Stars for 1925.0 (in Two Parts)
Fundamental Stars and Stars in the Zone +32d.0 to +64d.0
Royal Greenwich Obs.
<London (1935)>
ADC_Keywords: Positional data ; Proper motions
Description:
The observations for these two catalogs were made with the transit
circle at the Royal Observatory in Greenwich, England, between the
years 1922 and 1930 under the direction of Sir Frank Dyson, Astronomer
Royal. Part I contains fundamental stars contained in the annual
volumes of Greenwich Observations of the Sun, Moon and Planets. In
addition, 232 stars observed at the prime vertical, South of +32dDec.,
have been observed. Part II contains all stars down to 7.9 mag in the
A.G. scale between the limits of 32d and 64d Dec with the addition of
285 fainter stars in the sparse region of the sky from 12h to 16h RA.
From internal information, the probable error of one observation of a
star is found to be ±0.35 arcsec in RA and ±0.28 arcsec in DE. As
the number of observations is generally 5, the pe of a position in the
catalog, apart from systematic errors, should be ±0.15 arcsec. In
determining the proper motion of the fundamental stars, the positions
of this catalogue were combined with the First Greenwich Catalog of
Stars for 1925.0 (Observed 1915-1921), the two Pulkova Catalogues and
the two Cape Catalogues preceding this catalogue.
Note that the problable errors on the proper motions are not included
in this electronic version.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
greenw2a.dat 110 2111 Part I. Fundamental Stars reduced with
proper motion to the epoch 1925.0
greenw2b.dat 112 10587 Part II. Catalogue of Stars reduced without
proper motions to the epoch 1925.0
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See also:
I/33 : First Greenwich Catalogue
Byte-by-byte Description of file: greenw2a.dat
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Bytes Format Units Label Explanations
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2- 5 I4 --- No. Running number with the catalog.
7- 10 I4 --- PGC ? Preliminary General Catalog Number.
11- 15 F5.2 mag vmag ?=-9.99 Visual Magnitude (1)
16 A1 --- varFlag [-] A minus sign if star is variable (1)
18- 20 A3 --- SpType Spectral type (2)
22- 23 I2 h RAh Right Ascension 1925.0, Ep=1925.0 (hours).
25- 26 I2 min RAm Right Ascension (minutes).
28- 33 F6.3 s RAs Right Ascension (seconds).
35- 42 F8.4 s/yr AvarRA Annual Variation in RA (precession)
44- 51 F8.4 s/hyr SvarRA Secular Variation in RA (2nd term precess.)
53 A1 --- DE- Sign of the declination.
54- 55 I2 deg DEd Declination 1925.0, Ep=1925.0 (degrees).
57- 58 I2 arcmin DEm Declination (arcminutes).
60- 64 F5.2 arcsec DEs Declination (seconds).
66- 72 F7.3 arcsec/yr AvarDE Annual Variation in DEC (precession)
74- 80 F7.3 arcsec/hyr SvarDE Secular Variation in DE (2nd term precess.)
82- 84 I3 0.1yr epRA Mean Epoch of RA - 1900.0.
86- 88 I3 0.1yr epDE Mean Epoch of DE - 1900.0.
90- 92 I3 --- o_RAs No. of Observations of RA.
94- 96 I3 --- o_DEs No. of Observations of DE.
98 A1 --- Note [12349JQ0-] Notes (3)
100-104 I5 .1ms/yr pmRA Proper motion in RA.
106-110 I5 mas/yr pmDE Proper motion in DE.
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Note (1): When variable, only the brightest magnitude is given.
The published catalog gives the range in brightness and period.
Note (2): a * in the third byte means more than one spectral type has
been given for this star.
Note (3): The symbols used are:
1 = Brighter Star;
2 = Fainter Star;
3 = First Star;
4 = Second Star;
9 = Observed as one star;
J = Brighter Star, Reduction to center of gravity;
Q = Position is for center of gravity;
- = Double Star System;
O = Triple Star System.
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Byte-by-byte Description of file: greenw2b.dat
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Bytes Format Units Label Explanations
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2- 6 I5 --- No. Running number with the catalog.
7 A1 --- dflag [a] 'a' for supplementary star
9- 17 A9 --- BD Bonner Durchmusterung designation
18- 22 F5.2 mag vmag ?=-9.99 Visual Magnitude. (1)
23 A1 --- vFlag [-] A minus sign if star is variable. (1)
25- 27 A3 --- SpType Spectral type. (2)
29- 30 I2 h RAh Right Ascension 1925.0 (hours)
32- 33 I2 min RAm Right Ascension (minutes).
35- 39 F5.2 s RAs Right Ascension (seconds).
41- 47 F7.4 s/yr AvarRA Annual Variation in RA (precession)
49- 55 F7.4 s/hyr SvarRA Secular Variation in RA (2nd term precess.)
57 A1 --- DE- Sign of the declination.
58- 59 I2 deg DEd Declination 1925.0 (degrees).
61- 62 I2 arcmin DEm Declination (arcminutes).
64- 67 F4.1 arcsec DEs Declination (seconds).
69- 75 F7.3 arcsec/yr AvarDE Annual Variation in DE (precession)
77- 82 F6.3 arcsec/hyr SvarDE Secular Variation in DE (2nd term precess.)
84- 86 I3 0.1yr EpRA-1900 Mean Epoch of RA - 1900.0.
88- 90 I3 0.1yr EpDE-1900 Mean Epoch of DE - 1900.0.
92- 94 I3 --- o_RAs No. of Observations of RA.
96- 98 I3 --- o_DEs No. of Observations of DE.
100 A1 --- Note [1234679JLM0RQ] Note (3)
102-106 I5 0.1ms/yr pmRA Proper motion in RA.
108-112 I5 mas/yr pmDE Proper motion in DE.
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Note (1): When variable only the brightest magnitude is given.
The published catalog gives the range in brightness and period.
Note (2): a * in the third byte means more than one spectral type has
been given for this star.
Note (3): The symbols used are:
1 = Brighter Star;
2 = Fainter Star;
3 = First Star;
4 = Second Star;
6 = South Star;
7 = Mean of the two stars was observed;
9 = Observed as one star;
J = Brighter Star, Reduction to center of gravity;
L = First star. Reduction to center of gravity
M = Second star. Reduction to center of gravity
0 = Triple Star System
R = Observed as one star in some observations.
Q = Position is for center of gravity; -=Double Star System;
History:
* The catalogue was originally keypunched at the Astronomisches
Rechen-Institut, Heidelberg, Germany, before 1970.
* 18-Jul-1997: standardisation by Edward Shaya [SSDOO/ADC]
* 09-Nov-1999: minor correction by Francois Ochsenbein [CDS]
(End) Edward Shaya [SSDOO/ADC] 18-Jul-1997