GCVS - General Catalog of Variable Stars (June 2022 Version)

Overview

Work aimed at compiling detailed catalogs of variable stars in the Galaxy, which has been carried out continuously by Moscow variable-star researchers since 1946 on behalf of the International Astronomical Union, has entered the stage of the publication of the 5th, completely electronic edition of the General Catalog of Variable Stars (GCVS). The GCVS 5.1 is freely accessible on the Internet. The authors recommend citing their paper as a unified reference to the 5th edition of the GCVS.

The GCVS is the only reference source on all known variable stars. This version contains the electronically-readable version as distributed by the Sternberg Astronomical Institute and Institute of Astronomy (Russian Acad. Sci.), Moscow.

After the publication of Volume III of the 4th edition of the GCVS, the subsequent Name-lists with numbers from 67 to 77 contained only names of variable stars in the GCVS systems, together with their coordinates and variability types. The authors actually started compiling the 5th edition of the GCVS ten years ago, with the 78th Name-list of Variable Stars, which provided (as did all subsequent Name-lists) complete GCVS information for each star (in addition to the variability types, ranges of brightness variations, epochs of brightness maxima or minima, periods, etc.). In all, the 78th-81st Name-lists contain more than 13300 variable stars. The complete revision of information on the coordinates of variable stars (see the Introduction section of the reference paper) was also a part of the transition to the 5th edition.

The present electronic version of the GCVS5.1 is available from Sternberg Astronomical Institute (Lomonosov Moscow University) and Institute of Astronomy (Russian Academy of Sciences) at http://www.sai.msu.su/gcvs/gcvs/ as a first release of the fifth GCVS edition. Information on the contents and principles of the fifth edition can be found in Samus et al. (2017), the official reference to GCVS 5.1.

The GCVS 5.1 version contains data for individual variable objects discovered and named as variable stars by 2021 and located mainly in the Milky Way galaxy. The total number of named variable stars, not counting designated non-existing stars or stars subsequently identified with earlier-named variables, is now 58035. The stars of the GCVS 5.1 are stars of the GCVS fourth edition plus Name-lists Nos. 67-84. The stars from the Name-lists Nos.78-84 are presented in the complete GCVS format. Complete information for stars of the Name-lists Nos. 67-77 is so far provided in the first 20 constellations (Andromeda to Cepheus). In these constellations, the GCVS information has been completely revised with active use of new publications as well as observations retrieved by the GCVS compilers by data mining and used to determine new variability types and new light elements whenever possible. The authors are continuing this work and will introduce new data for the next constellations as soon as they are ready.

Catalog Bibcode

2017ARep...61...80S

References

General catalog of variable stars: Version GCVS 5.1,
    Samus N.N., Kazarovets E.V., Durlevich O.V., Kireeva N.N., Pastukhova E.N.
    <Astron. Zh. 94, 87 (2017)>
    =2017ARep...61...80S
    =2017AZh....94...87S

Provenance

This version of the GCVS catalog was last updated by the HEASARC in September 2022, based on the file at http://www.sai.msu.su/gcvs/gcvs/gcvs5/gcvs5.txt.

HEASARC Changes

The HEASARC has made a small number of mostly cosmetic changes to this catalog. Firstly, variable star names for the 335th to 999th variables in a constellation have had the zero following the 'V' character deleted, e.g., V335 And rather than V0335 And, to conform with the standard naming convention. Secondly, a number of the parameters that are flags had values of '*' in the original catalog; the HEASARC in some cases has changed these values to other symbols because an asterisk is a wild-card character in its database systems. Thirdly, the original values of the position_flag parameter of ":" "*" and "'" have been changed to A B and C, respectively, in this HEASARC version. Fourthly, the original values of the period_note parameter of *2, *N, and /N) have been changed to M2, MN, and FN, respectively, in this HEASARC version. Fifthly, the HEASARC has added two parameters, epoch_precision and period_precision, that give the number of decimal places to which the corresponding epoch and period parameters were given in the original table, e.g., if an entry has period_precision = 7, then its period was given to a precision of 10^-7 days. Sixthly, due to system limitations, the HEASARC has changed the "|" character (meaning "or") to a "/" in the new_variability_type parameter. Finally, the original value of '*' for the position_note parameter has been changed to 'Y' in the HEASARC version of this catalog.

Parameters

Variable_Star_Number
The GCVS numeric designation of the variable star, made from the constellation and star names codes. The numeric code for the constellation name is in alphabetic order of the full constellation name, so, for example, Cancer or CNC has a code value of 12 which precedes the code value of 16 for Capricornus or CAP). The codes are as follows:

  Constellation   Constell_code    Constellation   Constell_code
      Name                             Name

      And         1                    Ant         2
      Aps         3                    Aqr         4
      Aql         5                    Ara         6
      Ari         7                    Aur         8
      Boo         9                    Cae        10
      Cam        11                    Cnc        12
      CVn        13                    CMa        14
      CMi        15                    Cap        16
      Car        17                    Cas        18
      Cen        19                    Cep        20
      Cet        21                    Cha        22
      Cir        23                    Col        24
      Com        25                    CrA        26
      CrB        27                    Crv        28
      Crt        29                    Cru        30
      Cyg        31                    Del        32
      Dor        33                    Dra        34
      Equ        35                    Eri        36
      For        37                    Gem        38
      Gru        39                    Her        40
      Hor        41                    Hya        42
      Hyi        43                    Ind        44
      Lac        45                    Leo        46
      LMi        47                    Lep        48
      Lib        49                    Lup        50
      Lyn        51                    Lyr        52
      Men        53                    Mic        54
      Mon        55                    Mus        56
      Nor        57                    Oct        58
      Oph        59                    Ori        60
      Pav        61                    Peg        62
      Per        63                    Phe        64
      Pic        65                    Psc        66
      PsA        67                    Pup        68
      Pyx        69                    Ret        70
      Sge        71                    Sgr        72
      Sco        73                    Scl        74
      Sct        75                    Ser        76
      Sex        77                    Tau        78
      Tel        79                    Tri        80
      TrA        81                    Tuc        82
      UMa        83                    UMi        84
      Vel        85                    Vir        86
      Vol        87                    Vul        88

The star number within the constellation, which typically corresponds to the order in which the variables were found. For historical reasons, the first designated variable star in a constellation was given the name 'R constellation', e.g., 'R CMa', the second the prefix 'S', etc, the ninth 'Z', the tenth 'RR', etc., the 55th 'AA', etc, until the 334th 'QZ', at which point the letters have been exhausted, and the 335th variable is given the 'V0335' (or V335) prefix, e.g., 'V0335 And', and so on for all subsequent discoveries in the constellation.

Variable_Star_Cpt
The component identification, 'A', 'B', 1, 2, 4, 5, 8, 9, i.e., the designations of components of double/multiple stars. Thus, the star del² Gru has a value of 2 for this parameter to clearly distinguish it from the star del¹ Gru. Usually, only one component of the binary is variable, but there are 2 cases (CE Cas A and B, and EQ Peg A and B) where both components are variable and are listed as separate entries in the catalog.

Name
The variable star designation. For a brief explanation of the variable star naming convention, see the help entry for the variable_star_number parameter. Notice that stars which have Bayer designations, e.g. Alpha Ori, which have been discovered to be variable stars have not been given a new variable star designation but are listed by their Bayer designation in the GCVS, e.g., as 'alf Ori'. (The traditional transliterations of Greek letters are used, e.g., 'alf' for alpha). There are also a small number of historical variable stars which were named using lower-case latin characters, e.g. g Her and u Her. The lower- and upper-case latin letters must be distinguished, notice, because in some cases, e.g., u Her and U Her, there are names for completely different stars using the alternate naming conventions.

Note_Flag
This flag is set to 'Y' if there are notes on this star in the published version of the catalog. These comments can be found in http://www.sai.msu.su/gcvs/gcvs/gcvs5/remark.txt.

RA
The Right Ascension of the star in the specified equinox. This was given to a precision of no better than 0.01 seconds of time in the originating table. The position is not listed when the variable is equivalent to another catalogued variable in this GCVS table.

Dec
The Declination of the star in the specified equinox. This was given to a precision of no better than 0.1 arcsecond in the originating table. The position is not listed when the variable is equivalent to another catalogued variable in this GCVS table.

LII
The Galactic Longitude of the star. The position is not listed when the variable is equivalent to another catalogued variable in this GCVS table.

BII
The Galactic Latitude of the star. The position is not listed when the variable is equivalent to another catalogued variable in this GCVS table.

Position_Flag
This is a code flag describing the positional accuracy, as follows:

    ':'  means the position is uncertain.

Variability_Type
The type of variability according to the GCVS variability classification scheme. The system of variable star classification corresponds to the GCVS, 4th edition, with six additional classes (ZZO, AM, R, BE, LBV, and BLBOO) that were introduced in the Name-Lists 67 - 72 and in the GCVS vol. V. The full scheme is described in the file: http://cdsarc.u-strasbg.fr/ftp/cats/B/gcvs/vartype.txt. The HEASARC has made one change to the schema therein described: unique variable stars outside of the range of the GCVS classification scheme are designated as 'Unique', rather than by '*' as in the reference, so as to avoid confusion with the wild-card asterisk character.

Max_Mag_Limit
This parameter is a limit [<>] or amplitude flag [(] for the maximum magnitude, where '>' indicates that the latter is a faint limit, '<' that it is a bright limit, and '(' that it is an amplitude rather than an observed magnitude.

Max_Mag
The apparent magnitude at maximum brightness, or, if the value of limit_max_mag is '(', the amplitude of variation.

Max_Mag_Flag
This flag is set to ':' if the maximum magnitude is considered uncertain.

Min_Mag_Limit
This is a limit flag for the minimum magnitude, '>' indicating that the latter is a bright limit, and '(' that it is an amplitude rather than an observed magnitude.

Min_Mag
This parameter is either the apparent magnitude at minimum brightness, or, if the value of limit_min_mag is '(', the amplitude of variation.

Min_Mag_Flag
This flag is set to ':' if the minimum magnitude is considered uncertain.

Min_Mag_Alt_Sys
This is a code which is non-blank when the minimum magnitude or amplitude (min_mag) is given in an alternative photometric system to the one for the maximum magnitude (max_mag) which is given by the mag_system parameter. These codes are described in the parameter help for the mag_system parameter (see below).

Sec_Min_Mag_Limit
This is a limit flag for the secondary minimum magnitude, '>' indicating that the latter is a bright limit, and '(' that it is an amplitude rather than an observed magnitude.

Sec_Min_Mag
This parameter is either the apparent magnitude at secondary minimum brightness, or, if the value of limit_min_mag is '(', the amplitude of the variation (this information is given for eclipsing variable stars).

Sec_Min_Mag_Flag
This flag is set to ':' if the secondary minimum magnitude is considered uncertain.

Sec_Min_Mag_Alt_Sys
This is a code which is non-blank when the secondary minimum magnitude or amplitude (sec_min_mag) is given in an alternative photometric system to the one for the maximum magnitude (max_mag, which is given by the photometric system specified by the mag_system parameter). These codes are described in the parameter help for the mag_system parameter (see below).

Mag_System
The photometric system in which the maximum and minimum (unless min_mag_altsys and/or sec_min_mag_altsys are non-blank) magnitudes are reported. The main codes used are p or P or PH or pg (photographic magnitudes) and V (visual, photovisual, or Johnson's V). Several stars from the 68th Name-List have values of '1.' designating the 1.04 micrometer band of the system introduced by G.W. Lockwood. The designations u, v, b, and y refer to the Stroemgren system, the symbols 'Ic'and 'Rc' mean magnitudes in Cousins' RI system, 'g' designates magnitudes in the system of Thuan and Gunn, 'T' stands for broad-band Tycho magnitudes formed from B and V measurements, while 'r' indicates red magnitudes that are not tied to a particular system. Observations made in 'white light' are indicated by 'w' (rather than '*' as in the original table). Codes of Hp and T refer to the magnitudes used in th Hipparcos and Tycho missions, J, H, K, L, M to the standard infrared magnitudes, G to Gaia magnitudes, and u', g' r' i' to SDSS photmetric system magnitudes.

Epoch
This is generally the epoch for maximum light, in Julian Days, except for all eclipsing and ellipsoidal variables, as well as for RV Tau and RS CVn types, where it is the epoch for minimum light. This rule may occasionally be broken, but this is explained only in the remarks to the catalog.

The epochs are Julian dates, with the starting figures 24... omitted, i.e., JD-2,400,000.0 = MJD + 0.5, where MJD is the Modified Julian Date. The only exception is WY Sge, where the complete epoch is JD 237249.

Epoch_Precision
The precision of the quoted epoch value, i.e., the number of digits after the decimal point in the original table. Thus, a precision of 4 means that the epoch was given to 10^-4 days in the original table, which are not available in the machine-readable form at this time.

Epoch_Flag
This parameter is a flag qualifying the epoch according to the following codes:

    ':'   epoch is uncertain;
    '+'   epoch may be later than that reported;
    '-'   epoch may be earlier than that reported.

Nova_Year
The year of outburst for a nova or supernova. The exact date of maximum light is given in JD-2,400,000.0 in the epoch parameter.

Nova_Year_Flag
This parameter is set to ':' to indicate that there is uncertainty in the year of the nova or supernova outburst.

Period_Limit
A code qualifying the period, as follows: '>' or '<' if the period is a lower or upper limit, respectively, or '(' if the period is the mean cycle time of a U Gem or recurrent nova.

Period
The period of the variable star, in days. This is given with a range of precisions up to a possible maximum of 1.E-10 days in the original table.

Period_Precision
The precision of the quoted period value, i.e., the number of digits after the decimal point in the original table. Thus, a precision of 4 means that the period was given to a precision of 10^-4 days in the original table.

Period_Flag
This flag is set to ':' if the value of the period is considered uncertain.

Period_Note
This is another flag that contains information that the actual period may be either a multiple ('MN' or 'M2') or a fraction ('FN') of the quoted period value.

Rise_Eclipse_Time
This parameter contains either the rise time (M-m) for intrinsic variables, or the duration of the eclipse (D) for eclipsing binaries, both given as a percentage of the period value for the star. These values help to define the shape of the light curve.

Rise_Eclipse_Time_Flag
This flag is set to ':' if the rise time or eclipse duration given in the rise_eclipse_time parameter is considered uncertain.

Eclipse_Var_Note
This is a note used for eclipsing variables that is set to '0' when the duration of the constant brightness phase at minimum light (d) is equal to zero, or to ':' if the value is considered uncertain.

Spect_Type
The spectral type of the variable star.

Ref_Star
This is a reference code referring to a major study of the star, as follows (the codes and their corresponding references can be found in the file http://www.sai.msu.su/gcvs/gcvs/gcvs5/ref.txt):

    "00001" - if the main characteristics of the star were determined by
              the authors themselves;
    "00002" - "10204" - GCVS 4.2;
    "N0001" - "N0599" - New designations GCVS 5.1;
    "V 001" - "V ###" - Catalog of Extragalactic Variable stars;
    "67001" - "84009" - Name-Lists Nos. 67-84;
    "  HIP"           - The Special Name-List No.74 for Hipparcos Variables;
    "n0001" - "n####" - references to the Suspected variables (first part);
    "s0001" - "s####" - references to the Suspected variables (supplement).

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.

Ref_Chart
This is a reference code referring to a reference containing a chart or photograph of the star field, as follows (the codes and their corresponding references can be found in the file http://www.sai.msu.su/gcvs/gcvs/gcvs5/ref.txt):

    "00001" - if the main characteristics of the star were determined by
              the authors themselves;
    "00002" - "10204" - GCVS 4.2;
    "N0001" - "N0599" - New designations GCVS 5.1;
    "V 001" - "V ###" - Catalog of Extragalactic Variable stars;
    "67001" - "84009" - Name-Lists Nos. 67-84;
    "  HIP"           - The Special Name-List No.74 for Hipparcos Variables;
    "n0001" - "n####" - references to the Suspected variables (first part);
    "s0001" - "s####" - references to the Suspected variables (supplement).

Comment_Flag
This field is set to 'Y' if the particular star is believed either not to be a variable star or not to exist.

Alt_Name
This field may contain other names for the variable star. Firstly, it can contain the other cataloged variable star name for the same star in the GCVS: all necessary information on the star is to be found under that alternative name. Secondly, it can contain the star's alternate name in the GCVS Catalog of Extragalactic Variable Stars.

PM_RA
The proper motion of the star in the Right Ascension direction, in arcseconds per year.

PM_Dec
The proper motion of the star in the Declination direction, in arcseconds per year, given to a precision of 1 millisecond per year.

Coordinates_Epoch
The epoch of the tabulated coordinates. No epoch is provided when using coordinates taken from the literature if the epoch was not specified in the publication and could not be established.

Coordinates_Epoch_Flag
This parameter is, if not blank, a flag '?' indicating that the epoch of the coordinates is uncertain.

Ref_Astrometry_Flag
This flag parameter is set to '?' to indicates that the variable star's identification with the source catalog is considered uncertain.

Ref_Astrometry
A brief designation of the source reference for the astrometric data. In several cases, the catalog designation is folowed by the symbol "+pm"; this 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, roughly in the order of the authors' preference in identifying variable stars (see also the description of the catalogs provided for A.A. Volchkov's visualization code that they used at http://www.simfov.ru):

    Hip - The Hipparcos Catalog (ESA 1997).
    Tyc2 - The Tycho Catalog (Hog et al. 2000).  In isolated instances
    where the star is absent in the second Tycho catalog but is present in
    the first catalog (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 catalog, marked as A1.0); The Whole-Sky USNO-B1.0

New_Variability_Type
The new variability type of the star. Upon recommendations of the IAU Commissions 27 and 42, in 2006, the authors developed a new experimental system of classification for variable stars. See Section 2 of the reference paper or http://www.sai.msu.su/gcvs/gcvs/classif.htm for more details on this new scheme. Due to system limitations, the HEASARC has changed the "|" character (meaning "or") to a "/".

Class
The HEASARC Browse object classification, based on the spectral type parameter (spect_type), if there is information in this field, else based on the variability type parameter (variability_type).

Contact Person

Questions regarding the GCVS database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:27:56 EDT