Lomonosov Moscow State University Institute of Astronomy Russian Academy of Sciences

File Summary:
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 FileName        Explanations
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htm/index.html   HTML-site
gcvs5.txt        The GCVS 5.1 Catalog (main table)
ref.txt          References
remark.txt       Remarks

R, S, T, U, V, W, X, Y, Z
RR, RS, RT, RU, RV, RW, RX, RY, RZ
       SS, ST, SU, SV, SW, SX, SY, SZ
             TT, TU, TV, TW, TX, TY, TZ
                    UU, UV, UV, UX, UY, UZ
                            VV, VW, VX, VY, VZ
                                    WW, WX, WY, WZ
                                              XX, XY, XZ
                                                     YY, YZ
                                                             ZZ
AA, AB, AC, … AI, AK, AL, … AZ
        BB, BC, … BI, BK, BL, … BZ
               CC, … CI, CK, CL, … CZ
…
                           II, IK, IL, … IZ
                                KK, KL, … KZ
…
QQ, QR, QS, QT, QU, QV, QV, QX, QY, QZ.

The line for a variable star in the catalog begins with the first field, starting with a six-digit ordinal number. The first two digits are constellation numeric code in the alphabet order of their unabbreviated Latin names (01 for Andromeda, 02 for Antlia, … 88 for Vulpecula). The next four digits are the number of the variable star in this constellation. Thus, 010001 is R And; 725861 is V5861 Sgr. If the first digit after the constellation number is 9, it means that the last two digits correspond to a Greek or Latin letter, numbered in the alphabet order. In the case of the second digit after the constellation number being 0, this is a Greek letter. For example, 019001 is á And; 869024 is omega Vir. If the second digit after the constellation number is 1, the next digits correspond to a lowercase Latin letter (e.g., 179112 is l Car); 2 in this position corresponds to an uppercase Latin letter (189202 is B Cas). In a small number of cases, also used is the next position after the six-digit number is a digit that corresponds to a flag modifying the designation if the GCVS name contains an index. Thus, the six-digit number and the flag take the form 180106A and 180106B for the two variable components of the binary Cepheid CE Cas: CE Cas A and CE Cas B. 0390041 means delta 1 Aps; 6892122 is L2 Pup.

The traditional name of the variable star is presented in the next field. Note three-letter abbreviations of Greek letters in this field; they are the same as those used for Greek letters in SIMBAD.

For 51606 variable stars, our version provides new equatorial J2000.0 coordinates (right ascensions to within 0.01s and declinations to within 0.1"), for 23934 stars with allowance for their proper motions.

Note on Component:

designations of components of double/multiple stars: A,B; 1,2,3 ... (tau 1). Usually only one component of the binary is variable, but there exist two cases (CE Cas A,B; EQ Peg A,B) when both components are variable and enter the catalogue as separate lines.

Note on GCVS:

traditional transliterations of greek letters are used. Lower- and upper-case latin letters must be distinguished (e.g. u Her and U Her).

Note on NoteFlag:

An asterisk in this field means the presence of a remark in the file remark.txt .

Note on RAh, RAm, RAs, DE-, DEd, DEm, DEs:

the position is not listed when the variable is equivalent to another catalogued variable ("=" in column Exists, byte 168).

Note on u_DEs:

(:)a flag indicating that the coordinates are actually rougher than the accuracy standard adopted in the this table.

Note on n_magMax, n_magMin: Code for alternative photometric system.

Field is non-blank if magMin is a magnitude or amplitude given in a system other than that indicated by magCode. An asterisk in the corresponding position means the amplitude measured in white light.

Note on magCode:

the photometric system in which magMin and magMax are reported (see also Note on n_magMax, n_magMin). The main codes are P (photographic magnitudes) and V (visual, photovisual, or Johnson's V). Several stars from the 68th Name-List have in these positions "1." designating the 1.04 micrometer band of the system introduced by G.W.Lockwood. The designations u,v,b,y refer to the Stroemgren system. The symbols "Ic" and "Rc" mean magnitudes in Cousins' I system. "g" designates magnitudes in the system of Thuan and Gunn; "T" stands for broad-band Tycho magnitudes formed from B and V measurements; "r" are red magnitudes not tied to a particular system.

Note on Epoch:

Epochs are given for minimum light for all eclipsing and ellipsoidal variables, as well as for RV Tau and RS CVn types, and for maximum for all other types. This rule may occasionally be broken, but this is explained only in the remarks to the catalog, which are not available in machine-readable form at this time. The epochs are Julian dates, with the starting figures 24... omitted; The only exception is WY Sge, where the complete epoch is JD 2372494:. The codes ":" are used if the epoch is uncertain.

Note on q_Epoch:

the following codes are used (see also note on Epoch) :
":" are used if the epoch is uncertain;
"+" epoch may be later than that reported;
"-" epoch may be earlier than that reported.

Note on l_Period: the following codes are used:

">" or"<" if period is a lower or upper limit, respectively.
"(": the period is the mean cycle time of a U Gem or recurrent nova (in this case, there is ")" in pos. 129).

Note on n_Period:

the following codes are used: "*N" if the period may be a multiple of the quoted value;
"/N" if the period may be a fraction of the quoted value;
")" - see the note on l_Period.

Note on M-m/D:

this column holds the rising time (M-m) of intrinsic variables, or the duration of the eclipse (D) for eclipsing binaries. These values help to define the shape of the light curve. The value is given in percentage of the period of the star.

Note on u_M-m/D:

the "*" indicates that the duration of the light constancy phase at minimum light (d) for an eclipsing variable is equal to zero.

Note on Ref1, Ref2:

"00001" - if the main characteristics of the star were determined by the authors themselves.
"00002" - "10204" - GCVS 4.2
"N0001" - "N0412" - New designations GCVS 5.1
"V 001" - "V 554" - Catalogue of Extragalactic Variable stars
"67001" - "81321" - Name-Lists Nos.67-81
" HIP" - The Special Name-List No.74 for Hipparcos Variables.
If no chart is available for the variable, but the star is contained in one of the Durchmusterung catalogs or the Hubble Space Telescope Guide Star Catalog, the corresponding abbreviation (BD, CPD, CoD, GSC, HIP, USNO, 2MASS, UCAC2) is given.

Note on Exists:

"=" in byte 168 appears in two cases.

First, it is used if the variable is equivalent to another cataloged variable. In such case, after the "=" symbol, the alternative name of the variable follows, and all necessary information on the star is to be found under that alternative name.

Second , the "=" symbol may be followed by the star's name in the Catalogue of Extragalactic Variable stars.

Note on Epoch coor:

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;

Note on u_Ident:

The variable star's identification with the source catalog is uncertain;

Note on Ident :

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.

Note on VarTypeII:

Upon recommendations of the IAU Commissions 27 and 42, in 2006, we developed a new experimental system of classification for variable stars.

Note on GCVSII:

The repetition of the GCVS name.

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.

UCAC2 - US Naval Observatory CCD Astrograph Catalog (Zacharias et al., 2004).

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

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.

A2.0, B1.0 - A Catalog of Astrometric Standards (Monet et al., 1998) (there were rare cases when the star could be found only in the previous version of the catalogue, marked as A1.0); The Whole-Sky USNO-B1.0 Catalog of 1 045 913 669 Sources (Monet et al., 2003).

2MASS - The Two Micron All Sky Survey (Cutri et al., 2003).

GCVS - For some 10 stars, the coordinates were measured by the authors using Digitized Sky Survey images, plates from different collections, or other images.

Lit. - The coordinates taken from current astronomical periodicals.