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GCVSEGVARS - General Catalog of Variable Stars (GCVS4.2): Extragalactic Variables

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Overview

The General Catalog of Variable Stars (GCVS) is the only reference source on all known variable stars. This database is based on the electronically-readable version as distributed by the Sternberg Astronomical Institute and Institute of Astronomy (Russian Acad. Sci.), Moscow. It is the catalog of extragalactic variable stars, an updated version of the list contained in the GCVS (4th edition), Volume V. The total number of entries in this database is 10979 variable stars in 35 stellar systems (including the Magellanic Clouds, the Andromeda Galaxy, etc.). These variables include 144 stars now considered to be non-members of the galaxies in whose fields they lie, and 92 more stars that are possible non-members.

The present improved electronic version of the GCVS 4th Edition, Volumes I-V, combined with the Name-Lists of Variable Stars Nos. 67 - 77, is also available from the Sternberg Institute via anonymous ftp to ftp://ftp.sai.msu.su/pub/groups/cluster/gcvs/gcvs/ and more information is available via the Web at http://www.sai.msu.su/groups/cluster/gcvs/gcvs/ .


Catalog Bibcode

<II/250/evs_cat.dat>

References

General Catalogue of Variable Stars, 4th ed., vol. V.
Extragalactic Variable Stars
    Artiukhina N.M., Durlevich O.V., Frolov M.S., Goranskij V.P.,
    Gorynya N.A., Karitskaya E.A., Kazarovets E.V., Kholopov P.N.,
    Kireeva N.N., Kurochkin N.E., Lipunova N.A., Medvedeva G.I.,
    Pastukhova E.N., Samus N.N., Tsvetkova T.M.
   <"Kosmosinform", Moscow, (1995)>

Provenance

This online version of the GCVS Vol. V Catalog of Extragalactic Variable Stars was created by the HEASARC in January 2005 based on CDS Catalog II/250, table evs_cat.dat. The latter was itself based on on an electronically-readable version that was distributed by the Sternberg Astronomical Institute and Institute of Astronomy (Russian Acad. Sci.), Moscow.

HEASARC Changes

The HEASARC has made a small number of mostly cosmetic changes to this catalog. Firstly, variable star names have had all the zeroes following the 'V' character deleted, e.g., LMC V30 rather than LMC V0030, to follow the typical naming convention. Secondly, a number of the parameters that are flags (remark_flag, position_flag and eclipse_var_note) had non-alphanumeric values such as * " and ! in the original catalog which the HEASARC has changed to alphanumeric characters. Thirdly, the parameter limit_min_mag had a possible value of '<' in 541 entries in the original catalog, which value was used to designate an upper limit to the brightness (apparently), i.e., it means a lower limit to the minimum magnitude, or that the true minimum magnitude is fainter than the tabulated minimum magnitude. The HEASARC has changed all 541 of these values from '<' to '>' in order to conform to the normal practice for indicating 'fainter than' in magnitudes.

Parameters

Galaxy_Code
This is a numeric code for the galaxy name, ranging from 89 for the LMC to 123 for the WLM Galaxy (codes 1-88 in the GCVS are reserved for constellation names for galactic variable stars). The galaxy codes are as follows:

  Gal. Code   Galaxy     Gal. Code   Galaxy     Gal. Code   Galaxy

      89      LMC            90      SMC            91      M 31
      92      M 33           93      NGC 147        94      NGC 185
      95      NGC 205        96      NGC 300        97      Scl Galaxy
      98      IC 1613        99      ESO 356- 4    100      NGC 1313
     101      NGC 1466      102      Ret Galaxy    103      PGC 19441
     104      NGC 2366      105      NGC 2403      106      Holmberg II
     107      NGC 3031      108      Sextans B     109      Leo A
     110      NGC 3109      111      Leo I         112      Sextans A
     113      NGC 4365      114      NGC 4472      115      NGC 4486
     116      NGC 5128      117      NGC 5457      118      UGC 9749
     119      UGC 10822     120      NGC 6822      121      IC 5152
     122      UGC 12613     123      WLM Galaxy
  

Galaxy_Star_Num
The Variable Star Number within the specified galaxy.

Name
The GCVS Extragalactic Variable Star designation.

Remark_Flag
This flag is set to 'Y' if there is a remark on this star in the file: ftp://cdsarc.u-strasbg.fr/pub/cats/II/250/evs_rem.dat

RA
The Right Ascension of the star in the specified equinox. This was given to no better than a precision of 0.1 seconds of time in the originating table, and in 1950 equatorial co-ordinates.

Dec
The Declination of the star in the specified equinox. This was given to a precision of 1 arcsecond in the originating table, and in 1950 equatorial co-ordinates.

LII
The Galactic Longitude of the star.

BII
The Galactic Latitude of the star.

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

    'A'  means right ascensions accurate to one second of time and
         declinations accurate to one arcsecond;
    'B'  means declinations accurate to 0.1 arcminutes;
    'C'  means declinations accurate to one arcminute;
    'D'  means for V474 in the Sculptor system (V474 SclG), the listed
         coordinates refer to the galaxy's center since the coordinates
         of the star itself are unknown.
  

Variability_Type
The type of variability according to the GCVS variability classification scheme, with the addition of the new "BLBOO" type, named after the prototype star BL Boo = NGC 5466 V19 referring to the so-called "anomalous Cepheids", i.e. stars with periods characteristic of comparatively long-period RRAB variables, but considerably brighter in luminosity. There are also suspected variables designated by the symbol "var:".

Max_Mag
The apparent magnitude at maximum brightness.

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

Limit_Min_Mag
This is a limit flag for the minimum magnitude: '>' indicates that the min_mag value given is a bright limit, ie., the actual minimum magnitude is fainter than this value, while '(' means that the min_mag value given 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 min_mag value is considered uncertain.

Mag_System
The designation of the photometric band in which the magnitudes are given: P means photographic magnitudes, V means visual or photovisual magnitudes as well as Johnson V system magnitudes. In the latter case, they are usually distinguishable from visual magnitudes by the number of digits after the decimal point (as a rule, V system magnitudes are based upon photoelectric or CCD photometry). The letters U, B, R, I, J, H, K, L, M, N, O, Q mean, as a rule, magnitudes expressed in the corresponding systems of broad-band photometry.

Epoch
The epoch of maximum or minimum, expressed as the Julian Date. For eclipsing and ellipsoidal variables, RV Tau and RS CVn stars, the catalog gives the epoch of minimum light, while for the rest of variables, it gives the epoch of maximum light. For novae (variability_type N) and supernovae (variability_type SN), the epoch is completed by the year of the outburst (nova_year parameter).

Epoch_Flag
This flag is set to ':' if the epoch is considered uncertain.

Limit_Period
A code qualifying the period, that is set to '(' if the period is the mean cycle time of a U Gem star or recurrent nova.

Period
The period of the variable star, in days, or, if limit_period = '(', the mean cycle time of a U Gem star or recurrent nova. This parameter is given with a range of precisions up to a possible maximum of 1.E-08 days in the original table.

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

Rise_Eclipse_Time
This parameter contains either the rise time (M-m, the duration of light increase from minimum to maximum) for intrinsic variables, or the duration of the eclipse (D) for eclipsing or Algol-type binaries. The value is given as a percentage of the period of the star.

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 light constancy phase at minimum light (d) is equal to zero.

Spect_Type
The spectral type of the variable star. If there exist several spectral type determinations for a star, the more recent ones have been preferred, taking into account the reliability of each determination. The symbols "d" (dwarfs) and "g" (giants) have been converted into luminosity classes V and III, respectively. If a star showed spectral features typical of novae during or after the outburst, a symbol 'NOVA' is given in this parameter. If the spectrum showed features characteristic of U Gem variables, this parameter contains the symbol 'UG'. A continuous spectrum is designated as 'cont', the symbol 'e' means an emission-line spectrum, lower-case letters 'ea', 'eb' in this field stand for 'e alpha', 'e beta'. For RR Lyrae stars, spectral types derived from hydrogen lines are given. A plus sign (+) between two spectral type values means that the spectra of two components of a spectroscopic binary are observed. Two spectral type values separated with a minus sign (-) give the range of spectral type variations in the process of brightness changes.

Ref_Star
This is a reference code referring to a major study of the star, the key to which can be found in the file: ftp://cdsarc.u-strasbg.fr/pub/cats/II/250/refs.dat

Ref_Chart
This is a reference code referring to a study that contains a chart or photograph of the star field, the key to which can be found in the file: ftp://cdsarc.u-strasbg.fr/pub/cats/II/250/refs.dat

Alt_Name_1
An alternative designation for the variable star that is used in the reference whose code is given in the ref_star parameter.

Alt_Name_2
An alternative designation for the variable star that is used in the reference whose code is given in the ref_chart parameter.

GCVS_Nsv_Name
The alternative GCVS or NSV designation for the variable star.

Non_Member
This is a flag indicating the nonmembership status of the variable star in the Galaxy in whose field the star lies. The symbols 'N' or 'N:' indicate nonmembership and possible nonmembership, respectively, in the galaxy in question. For the stars that are in the main GCVS (vols. I-III) or the GCVS Catalog of Newly Suspected Variables (NSV) and which are not members of the corresponding galaxy, the present catalog typicallu gives only the Extragalactic Variable running number, the coordinates, the symbol 'N' in this field, and the GCVS or NSV name.

Nova_Year
The year of outburst of the star, if a nova.

Nova_Year_Flag
This flag is set to ':' if the outburst year of the nova is considered uncertain.

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 GCVSEGVARS database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 28-Jan-2005