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An Electronic Version of Volume I of the General Catalogue of Variable
Stars with Improved Coordinates

N.N. Samus', V.P. Goranskii, O.V. Durlevich, A.V. Zharova,
E V. Kazarovets, E.N. Pastukhova, M.L. Hazen, and T.M. Tsvetkova

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Astronomy Letters, Vol. 28, No. 3, 2002, pp. 174-181. Translated from
Pis'ma v Astronomicheskii Zhurnal, Vol. 28, No. 3, 2002, pp. 201--209.

Russian Academy of Sciences, ul. Pyatnitskaya 48, Moscow, 109017 Russia
Sternberg Astronomical Institute, Universitetskii pr. 13, Moscow,
119899 Russia
Harvard Observatory, 60, Garden Str., Cambridge, MA, 02138 USA

Received October 17, 2001
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We present a new electronic version of the first volume of the General
Catalogue of Variable Stars (GCVS), fourth edition, which contains data
on 10558 variable stars in Andromeda - Crux (the constellations are
ordered in the Catalog according to the Latin alphabet). This version
incorporates the name lists of variable stars from no.67 to no.76 for
the same constellations. The main distinctive feature of the new
version is that it provides improved equatorial J2000.0 coordinates for
10351 stars (including those for 4592 stars corrected for proper
motions). These are based on identifications with positional catalogs
using finding charts and on our new measurements. We searched for a
number of stars on original plates from the plate collections of several
observatories. So far we have failed to determine accurate coordinates
for 207 variable stars, because there are no finding charts and because
the information for star identification is insufficient. The version
also includes a file of remarks to the first GCVS volume and a
preliminary version of the file of bibliographic references to the
entire fourth edition of the GCVS. Apart from a complete update of the
positional information, the new version incorporates all the other
corrections that were found to be necessary after the first GCVS volume
was published (1985).

Key words: stars - variable and peculiar

www.sai.msu.su/groups/cluster/gcvs/gcvs/vol1/
ftp.sai.msu.su/pub/groups/cluster/gcvs/gcvs/vol1/

File Summary:
-----------------------------------------------------------------
FileName Explanations
-----------------------------------------------------------------
readme.txt This file
vol1.pdf The text of the paper
vol1.dat The new electronic version of volume I of the GCVS4
vol1_pos.dat The positional information for the stars of volume I
of the GCVS4
rem.txt The list of remarks to volume I
ref.txt The list of references for volumes I-III
-----------------------------------------------------------------

The file vol1.dat
-------------------

The main table (vol1.dat) of the new electronic version of volume I
of the GCVS contains information on 10558 objects (not counting the
stars that were erroneously named for the second time or proved to be
nonexistent) in Andromeda - Crux, which are mostly variable stars of
our Galaxy discovered and named before 2001; i.e., it covers the
variable stars that were included in the fourth edition of the GCVS and
name lists nos. 67 - 76 (for the same constellations).

The structure of the main table corresponds to that of the combined
table of the GCVS 4th edition and the name lists (Kholopov et al. 1998;
see also www.sai.msu.su/grops/cluster/gcvs/gcvs/iii/). The differences
between these tables are as follows:

(1) Instead of B1950.0 coordinates, we provide new improved equatorial
J2000.0 coordinates.

(2) The most recent name lists, up to no. 76, were included.

(3) We included all the corrections and changes that were found
necessary during our work on the GCVS in other columns of the main
table, in references, and in remarks. Note that for stars that had no
published finding charts but that we identified with the GSC or with the
US Naval Observatory (USNO) A1.0/A2.0 catalogs, we now give a symbol of
the corresponding catalog (GSC, USNO) as a reference to the finding
chart.

The main table is presented in the form traditional for the GCVS, i.e.,
in the order of constellations and variable-star names adopted in the
GCVS. The table includes the following information: equatorial J2000.0
coordinates (right ascensions to within 0.1s and declinations to within
1"), variability types, magnitudes at maximum and minimum light,
photometric magnitude systems, periods of light variations, durations of
brightness rise from minimum to maximum of eclipse durations, spectral
types, and bibliography. For the stars from name lists no. 67 - 76
published after the appearance of the GCVS 4th edition, we provide not
all columns of the table but only coordinates, variability types,
magnitudes, and bibliography; the missing data will be added to the 5th
edition of the GCVS.

Byte-by-byte Description of file: vol1.dat
------------------------------------------------------------------------------
Bytes Format Units Label Explanations
------------------------------------------------------------------------------
1- 2 I2 --- Constell [1/88]Constellation numeric code
3- 6 I4 --- Number Star number within the constellation
7 A1 --- Component Component identification
9- 18 A10 --- GCVS Variable star designation
19 A1 --- NoteFlag [*] Notes in published catalog
(see file rem.txt)
21- 22 I2 h RAh Hours RA, equinox J2000.0
23- 24 I2 min RAm Minutes RA, equinox J2000.0
25- 28 F4.1 s RAs Seconds RA, equinox J2000.0
29 A1 --- DE- Sign Dec, equinox J2000.0
30- 31 I2 deg DEd Degrees Dec, equinox J2000.0
32- 33 I2 arcmin DEm Minutes Dec, equinox J2000.0
34- 35 I2 arcsec DEs Seconds Dec, equinox J2000.0
36 A1 --- u_DEs *[:*] position accuracy flags
38- 47 A10 --- VarType Type of variability(see file
www.sai.msu.su/grops/cluster/gcvs/gcvs/iii/vartype.txt)
49 A1 --- l_magMax [<>(] ">" if magMax is a faint limit
"<" if magMax is a bright limit
"(" if magMax is an amplitude
50- 55 F6.3 mag magMax Magnitude at maximum brightness
56 A1 --- u_magMax Uncertainty flag (:) on magMax
56 A1 --- n_magMax Alternative photometric system for magMax
57 A1 --- f_magMax [)] ")" if magMax is an amplitude
59 A1 --- l_magMin [<(] "<" if magMin is a bright limit
"(" if magMin is an amplitude
60- 65 F6.3 mag magMin Minimum magnitude or amplitude
66 A1 --- u_magMin Uncertainty flag (:) on magMin
67- 68 A2 --- n_magMin Alternative photometric system for magMin
69 A1 --- f_magMin [)] ")" if magMin is an amplitude
71- 72 A2 --- magCode The photometric system for magnitudes
74- 84 F11.5 d Epoch Epoch for maximum light, Julian days
85 A1 --- q_Epoch [:+-] Quality flag on Epoch
86- 90 A4 --- YearNova Year of outburst for nova or supernova
91 A1 --- q_Year [:] Quality flag on Year of outburst
93 A1 --- l_Period [<>(] Code for upper or lower limits
94-109 F16.10 d Period Period of the variable star
110 A1 --- u_Period Uncertainty flag (:) on Period
111-112 A1 --- n_Period [*/N)]
114-116 A3 % M-m/D Rising time (M-m) or duration of eclipse (D)
117 A1 --- u_M-m/D Uncertainty flag (:) on M-m/D
118 A1 --- n_M-m/D [*] Note for eclipsing variable
120-136 A17 --- SpType Spectral type
138-142 A5 --- Ref1 Reference to a study of the star (ref.txt)
144-148 A5 --- Ref2 Reference to a chart or photograph (ref.txt)
150-161 A12 --- Exists Cases of non-existence of the variable etc.
-------------------------------------------------------------------------------

POSITION ACCURACY FLAGS -
(*) - So far we have failed to determine accurate coordinates for 207
variable stars, because there are no finding charts and because the
information for star identification is insufficient. The coordinates
that could not be improved were recalculated from old rough coordinates
to the equinox J2000.0 with allowance for precession.
(:) - A flag indicating that the coordinates are actually rougher than
the new accuracy standard adopted in the table vol1_pos.dat (see below).


The file vol1_pos.dat
---------------------

For 10351 variable stars, our version provides new equatorial J2000.0
coordinates (right ascensions to within 0.01s and declinations to within
0.1"), for 4592 stars with allowance for their proper motions.

The table vol1_pos.dat provides positional information based on our
identifications with major astrometric catalogs, on published data, or
on our new measurements (see below) for 10351 stars of the new version
of volume I (including stars of the new name lists in the same
constellations). The order of stars in this table is the same as that in
the main table.

Byte-by-byte Description of file: vol1_pos.dat
------------------------------------------------------------------------------
Bytes Format Units Label Explanations
------------------------------------------------------------------------------
1- 2 I2 --- Constell [1/88]Constellation numeric code
3- 6 I4 --- Number Star number within the constellation
7 A1 --- Component Component identification
9- 18 A10 --- GCVS Variable star designation
20- 21 I2 h RAh Hours RA, equinox J2000.0
22- 23 I2 min RAm Minutes RA, equinox J2000.0
24- 28 F5.2 s RAs Seconds RA, equinox J2000.0
30 A1 --- DE- Sign Dec, equinox J2000.0
31- 32 I2 deg DEd Degrees Dec, equinox J2000.0
33- 34 I2 arcmin DEm Minutes Dec, equinox J2000.0
35- 38 F4.1 arcsec DEs Seconds Dec, equinox J2000.0
39 A1 --- u_DEs *[:] position accuracy flag
41- 46 F6.3 arcsec/yr PMa Proper motion RA
48- 53 F6.3 arcsec/yr PMd Proper motion DE
55- 62 F8.3 yr Epoch *Epoch
64 A1 --- u_Ident *Uncertainty flag (?) on identification
66- 77 A12 --- Ident *The source of astrometric data
-------------------------------------------------------------------------------

POSITION ACCURACY FLAG (:) - indicating that the coordinates are
actually rougher than the new accuracy standard adopted in the catalog,
because we failed to determine better coordinates and to find them in
source catalogs or in publications. In comparatively numerous cases,
such coordinates were obtained by transforming B1950.0 coordinates from
the IRAS Point Sorce Catalog (see below).

EPOCH of the given coordinates. No epoch is provided when using the
coordinates from the literature if the epoch was no specified in the
publication and cold not be established;

FLAG (?) ON IDENTIFICATION - the variable star's identification with
the source catalog is uncertain;

THE SOURCE OF ASTROMETRIC DATA - A brief designation of the source of
astrometric data. In several cases, the catalog designation is folowed
by the symbol "+pm"; it implies that the position for a certain epoch
was taken from the catalog and reduced to the epoch 2000.0 using
information on the star's proper motion from a different source.

Below, we give a list of the major catalogs and other data sources used,
roghly in the order of our preference in identifying variable stars
(see also the description of the catalogs provided for A.A. Volchkov's
visualization code we used at www.simfov.ru).

Hip - The Hipparcos Catalogue (ESA 1997).

Tyc2 - The Tycho Catalogue (Hog et al. 2000). In isolated instances
where the star is absent in the second Tycho catalogue but is present in
the first catalogue (ESA 1997), the source is indicated as Tyc1.

PPM - The Positions and Proper Motions (Roser et al. 1991-1993).

NPM - The Lick Northern Proper Motion Program (Klemola et al. 1987).

AC - The Four-Million Star Catalog (see Gulyaev and Nesterov 1992).

ACT - The ACT Reference Catalog (Urban et al. 1997).

GSC - The Guide Star Catalog (Lasker et al. 1990). The symbol "ns"
accompanying a GSC reference implies that the entry is marked as a
nonstellar object in the cited catalog.

GSC 2.2 - The Guide Star Catalog, Version 2.2.01, 2001, Space Telescope
Science, Institute and Osservatorio Astronomico di Torino.

A2.0 - A Catalog of Astrometric Standards (Monet et al. 1998). There are
rare cases where the star could be found only in the previous version of
the catalog; they are marked as A1.0.

IRAS - The Infrared Astronomical Satellite Catalogue of Point Sources
(Neugebauer et al. 1988). We used it only when it was impossible to
identify a star with positional catalogs or to find a star at optical
wavelengths and independently measure its coordinates.

GCVS AUTHORS - For some 200 stars (1.8% of all the stars in the new
version), we measured their coordinates using Digitized Sky Survey
images, plates from various collections, or other images. As a rule, we
used A2.0 catalog stars as the reference stars in our measurements using
the Digitized Sky Survey. The rectangular coordinates of stars were
measured by an eye-pointing of the cursor at their photometric centers
in commercially available image processing applications with a large
magnification. The measurements were reduced by Turner's linear method.
The accuracy of our measurements was typically about 0.5" both in right
ascension and in declination.

LITERATURE - The coordinates taken from current astronomical periodicals.


The files rem.txt and ref.txt
-----------------------------

The list of remarks to volume I (rem.txt) includes information that
supplements the main table for 2167 stars. In contrast to
the printed bilingual version of the 4th GCVS edition (Kholopov et al.
1985-1988), all remarks in the file are given only in English and
generally correspond to the English text of the remarks in the printed
edition. The remarks contain, in particular, information on variable
stars in double systems, on period variability, on secondary minima of
eclipsing variables, and on proximity to star clusters and nebulae in
the sky. For unique variable stars, the remarks give detailed
descriptions of the variability pattern.

The preliminary version of bibliographic references (ref.txt) for volumes
I-III of the 4th edition contains 12979 references to the literature from
the main table and remarks. All references in Cyrillic alphabet in the
printed version were transliterated into the Latin alphabet in this
file.

Acknowledgments
---------------

We are grateful to A.A. Volchkov and J. Manek for providing us with the
necessary software. We wish to thank S.V. Antipin for assistance, L.N.
Berdnikov for providing unpublished finding charts for several southern
Cepheids, C. Lopez (Argentina), N.T. Ashimbaeva, and G.V. Romanova for
making their results available to us prior to their publication. We
also wish to thank the researchers, primarily D. Williams (USA), who
helped us to identify the "lost" variable stars using plates of other
observatories. This study was supported in part by the Russian Foundation
for Basic Research (project no. 99-02-16333), the Program of Support
for Leading Scientific Schools of Russia (project no 00-15-96627), the
Federal Program "Astronomy', and the American Association of Variable
Star Observers. We used the Digitized Sky Survey images provided by the
Hubble Space Telescope Science Institute under support from grant NAG
W-2166 of the USA Government.

References
----------

1. E. Hog, C. Fabricius, V. V. Makarov, et al., The Tycho-2 Catalogue,
CD-ROM (Copenhagen, 2000).

2. P. N. Kholopov, N. N. Samus', M. S. Frolov, V.P. Goranskii, N. A.
Gorynya, E. A. Karitskaya, E. V. Kazarovets, N. N. Kireeva, N. P.
Kukarkina, N. E. Kurochkin, G. I. Medvedeva, N. B. Perova, A. S.
Rastorguev, and S. Yu. Shugarov, General Catalogue of Variable Stars
(Nauka, Moscow, 1985-1988), Vols. I-III.

3. P. N. Kholopov, N. N. Samus, N. M. Artiukhina, O. V. Durlevich, M. S.
Frolov, V. P. Goranskij, N. A. Gorynya, E. A. Karitskaya, E. V.
Kazarovets, N. N. Kireeva, N. P. Kukarkina, N. E. Kurochkin, N. A.
Lipunova, G. I. Medvedeva, E. N. Pastukhova, N. B. Perova, A. S.
Rastorguev, S. Yu. Shugarov, and T. M. Tsvetkova, Centre de Donnees
Astronomiques de Strasbourg, II/214A (1998).

4. A. R. Klemola, R. B. Hanson, and B. F. Jones, Centre de Donnees
Astronomiques de Strasbourg, I/199 (1987).

5. B. M. Lasker, C. R. Sturch, B. J. McLean, et al., Astron. J. 99,
2019 (1990).

6. C. Lopez, private communication (1998).

7. D. Monet, A. Bird, B. Canzian, et al., USNO-A V2.0. A Catalog of
Astrometric Standards (US Naval Observatory, Washington, 1998), 11 CD
ROMs.

8. G. Neugebauer, R. J. van Duinen, H. J. Habing, et al., IRAS Point
Source Catalog (NASA, Washington, 1988).

9. On the Four-Million Star Catalog, Ed. by A. P. Gulyaev and V. V.
Nesterov (Mosk. Gos. Univ., Moscow, 1992).

10. S. Roeser, U. Bastian, L. I. Yagudin, and V. V. Nesterov, PPM
Star Catalogue. Positions and Proper Motions (Astronomisches
Rechen-Institut, Heidelberg, 1991-1993).

11. The Hipparcos and Tycho Catalogues (European Space Agency, 1997),
ESA SP-1200.

12. S. E. Urban, T. E. Corbin, and G. L. Wyckoff, The ACT Reference
Catalog (US Naval Obs., Washington, 1997).

13. A. A. Volchkov and O. A. Volchkov, http://www.simfov.ru, 2001.