GCVSNSVARS - General Catalog of Variable Stars: Suspected Variable Stars (June 2022 Version)

Overview

This catalog is a compilation of stars that have been suspected of variability but have (mostly) not been finally designated as variables. It is the merging and latest updated version of the compilation of the New Catalog of Suspected Variable Stars (NSV Catalog) originally published in 1982 by Kukarkin et al. and the Supplement to the NSV originally published in 1998 by Kazarovets et al. This version (NSV Release 2) has updated the previous catalog in several ways. The accuracy of coordinates has been drastically improved for the objects in the catalog; for most of them, the authors have revised the photometric and spectroscopic data and updated the remarks. In the cases with no existing finding charts, the authors recovered variability of 2800 stars of the catalog, despite large errors of the previously published coordinates.

The data contained in the present catalog include positions, magnitudes, variability types, references to the literature, and spectra.

Catalog Bibcode

References

Revised Version of the New Catalogue of Suspected Variable Stars,
    NSV Release 2, Kazarovets, E. V., Samus, N.N. and Durlevich, O. V.
    <Astronomy Reports (2022)>
    =2022ARep...66..555K
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
New Catalogue of Suspected Variable Stars,
    Kukarkin B.V., Kholopov P.N., Artiukhina N.M., Fedorovich V.P.,
    Frolov M.S., Goranskij V.P., Gorynya N.A., Karitskaya E.A.,
    Kireeva N.N., Kukarkina N.P., Kurochkin N.E., Medvedeva G.I.,
    Perova N.B., Ponomareva G.A., Samus N.N., Shugarov S.Yu.
    <Moscow: Nauka Publishing House (1982)>
New Catalogue of Suspected Variable Stars. Supplement - Version 1.0
    Kazarovets E.V., Durlevich O.V., Samus N.N.
    <Institute of Astronomy of Russian Academy of Sciences and
    Sternberg Astronomical Institute (1998)>
    =1998IBVS.4655....1K

Provenance

This version of the GCVS catalog was last updated by the HEASARC in September 2022, based on the files http://www.sai.msu.su/gcvs/gcvs/nsv2/nsv2.txt and http://www.sai.msu.su/gcvs/gcvs/nsvsup/nsvs.dat.

HEASARC Changes

The HEASARC has made a small number of mostly cosmetic changes to this catalog. Firstly, the suspected variable star names have had all their leading zeroes following the 'NSV' prefix deleted, e.g., NSV 2 rather than NSV 00002, to follow the standard naming convention. Secondly, a number of the parameters (e.g., note_flag, position_flag, mag_system) had values of '*' in the original catalog which the HEASARC has changed to alphanumeric characters. Thirdly, the parameter limit_min_mag had a value of '<' in a number of the 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 of these occurrences from '<' to '>' in order to conform to the normal practice for indicating 'fainter than' in magnitudes.

Parameters

Name
The GCVS Suspected Variable Star prefix NSV (for New Suspected Variable) together with a running number (from 1 to 14812 for stars in the original 1982 NSV Catalog, and from 15001 to 26206 for stars in the 1998 Supplement to the NSV). Leading zeroes have been removed from the running number.

NSV
The NSV Catalog running number (from 1 to 14812 for stars in the original 1982 NSV Catalog, and from 15001 to 26206 for stars in the Supplement to the NSV). Leading zeroes have been removed from the running number, notice.

Note_Flag
This is a flag that is set to 'Y' if there are remarks on the star in the file http://www.sai.msu.su/gcvs/gcvs/nsv2/rem.txt.

The remarks contain information covering situations such as, e.g.:

    1. The discoverer of the light variability is not the author of the
       paper cited in the variability reference, or is one of several
       authors of the paper cited.  In these cases, discoverers' names are
       given in original transcriptions of the remarks.

    2. The most important additional information about a star, although
       the NSV Supplement compilers did not intend to present complete
       bibliographies for any cataloged stars.

    3. Remarks for visual binaries giving visual magnitudes for the
       individual components A and B, angular separations, and position
       angles for faint components (or semi-major axis of a relative orbit
       and period of orbital motion). Then, data for other components are
       given where applicable. (Combined magnitudes are generally reported
       in the main database table).

Designations of components of double/multiple stars: A,B,C ...; a,b,c ...; 1,2,3 ...; the symbols p = preceding, f = following, N = northern, S = southern, E = eastern, W = western may also appear. If specific component no indicated, then coordinates in the Table refer to the primary component.

RA
The Right Ascension of the star in the specified equinox. This was given to a precision of 0.01 seconds of time in J2000 equatorial coordinates in the originating table.

Dec
The Declination of the star in the specified equinox. This was given to a precision of 0.1 arcsecond in J2000 equatorial coordinates in the originating table.

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-tenth of an arcminute
    'B'  means declinations accurate to 1 arcminute

PM_RA
The star's proper motion in Right Ascension, in arcsec/yr.

PM_Dec
The star's proper motion in Declination, in arcsec/yr.

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.

Ref_Astrometry
This field specifies the reference source of the astrometric data for the star.

Variability_Type
The type of variability according to the GCVS (4th Edition) variability classification scheme, with the addition of six new types (ZZO, AM, R, BE, LBV, BLBOO) that were introduced in the Name-Lists 67-72 and in the GCVS vol. V. Descriptions of the 6 new types only are given below, while the entire classification scheme is described in the file http://cdsarc.u-strasbg.fr/ftp/cats/B/gcvs/vartype.txt. The new types are:

  ZZO    ZZ Cet type variables of the DO spectral type showing HeII and
         and CIV absorption lines in their spectra.

  AM     AM Her type variables; close binary systems consisting of a
         dK-dM type dwarf and of a compact object with strong magnetic
         field, characterized by variable linear and circular polarization
         of light. The total range of light variations may reach 4-5 mag V.

  R      Close binary systems characterized by the presence of strong
         reflection (re-radiation) of the light of the hot star
         illuminating the surface of the cooler companion.  Light curves
         are sinusoidal with the period equal to Porb, maximum brightness
         coinciding with the passage of the hot star in front of the
         companion.  The eclipse may be absent.  The range of light
         variation is about 0.5-1.0 mag V (KV Vel).

  BE     It becomes more and more clear that, although the majority of Be
         stars are photometrically variable, not all of them could be
         properly called GCAS variables.  Quite a number of them show
         small-scale variations not necessarily related to shell events; in
         some cases the variations are quasi-periodic.  By now we are not
         able to present an elaborated system of classification for Be
         variables, but we adopt a decision that in the cases when a Be
         variable cannot be readily described as a GCAS star we give simply
         BE for the type of variability.

  BLBOO  The so-called "anomalous Cepheids", i.e. stars with periods
         characteristic of comparatively long-period RRAB variables, but
         considerably brighter by luminosity (BL Boo = NGC 5466 V19).

  EP     Stars showing eclipses by their planets. Prototype: V0376 Peg.

  SRS    Semiregular pulsating red giants with short period (several days
         to a month), probably high-overtone pulsators. Prototype: AU Ari.

  LPB    The comparatively long-period pulsating B stars (periods exceeding one day).

Variability_Flag
This is a flag that is set to the value of '-' if a star's variability seems doubtful or erroneous according to the compilers of the NSV Catalog.

Limit_Max_Mag
This is a limit flag for the maximum magnitude: '<' indicates that the max_mag value given is a numerical upper limit, i.e., the actual maximum magnitude may be brighter than this value, while '>' means that the max_mag value given is a numerical lower limit, i.e., the actual maximum magnitude may be fainter than this value.

Max_Mag
The apparent magnitude at maximum brightness. Magnitudes are reported to hundredths if the observations are photoelectric or CCD, to tenths or whole magnitudes if they are not. If only an amplitude has been measured photoelectrically, then the maximum magnitude is generally given to tenths only and the minimum is reported to hundredths.

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

Limit_Min_Mag
This field may contain flag(s) indicating limit and/or amplitude for the min_mag value.

If the field contains '(', that indicates that the quoted min_mag value is an amplitude relative to the value of the max_mag parameter, rather than the actual minimum magnitude, and the limit, if present, applies to this amplitude.

If the value is '>', then the min_mag value given is a bright limit, i.e., the actual minimum magnitude may be fainter than this value, while if the value is '<', then the min_mag value given is a faint limit, i.e., the actual minimum magnitude may be brighter than this value.

Min_Mag
The minimum apparent magnitude, or the amplitude of variability. If the value of limit_min_mag contains '(', this indicates that the min_mag value given is an amplitude rather than an observed minimum magnitude. Magnitudes are reported to hundredths if the observations are photoelectric or CCD, to tenths or whole magnitudes if they are not. If only an amplitude has been measured photoelectrically, then the maximum magnitude is generally given to tenths only and the minimum is reported to hundredths. If the value of min_mag_flag is 'st', then the quoted value of min_mag is an amplitude in steps rather than magnitudes, and the original references should be consulted for further information.

Min_Mag_Flag
This flag is set to ':' if the min_mag value is considered uncertain, and is set to 'st' if the quoted value of min_mag is an amplitude in steps rather than magnitudes, and the original references should be consulted for further information. In 3 cases (NSV 25926, NSV 25927 and NSV 25981) the value is set to 'A' (the HEASARC changed the original '*' since an asterisk is used as a wild card character in its system): the significance of this flag value is not specified in the original CDS documentation.

Mag_System
A code for the photometric system in which the max_mag and min_mag value are reported (if the value of min_mag_system is blank), or for the photometric system in which the max_mag value only is reported (if the value of min_mag_system is non-blank). The main codes are V (visual, photovisual, or Johnson V), B (Johnson B) and p (photographic magnitudes). The designations u, v, b, y refer to the Stroemgren system. The symbols Ic and Rc mean magnitudes in the Cousins I, R 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 are red magnitudes not tied to a particular system. A value of 'w' for this parameter means that the quoted magnitude is for a white-light measurement. Several stars from the 68th Name List have values of '1.' for this parameter to designate the 1.04 micron band of the system introduced by G.W. Lockwood.

Ref_Star
This is a reference code referring to a study of the star, the key to which can be found in the file http://www.sai.msu.su/gcvs/gcvs/nsv2/ref.txt.

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 file http://www.sai.msu.su/gcvs/gcvs/nsv2/ref.txt.

Alt_Name
The identification of the suspected variable in the paper whose code reference is given in the ref_star parameter. DM numbers are given without a prefix, the standard naming convention of "The Henry Draper Catalogue" being used (BD for declination zones +89 to -22, CD for zones -23 to -51, and CP for zones -52 to -89). Some identifications are given by coordinate designations, a 6-digit number consisting of hours, minutes, and seconds (or tenths of a minute) of time and degrees of declination with sign included. A value of 'Y' signifies that a designation is given in the remarks to the published catalog. This parameter is not populated for the stars in the NSV Supplement (entries with values of the nsv parameter of 15001 or greater).

Spect_Type
The spectral type and luminosity class of the suspected variable star, if known. Spectral types from the HD Catalog are generally given in parentheses. Also, the following (non-standard) symbols may be used:

                    AF     for A-F type stars
                    BA     for B-A type stars
                    e      emission spectrum
                    ea     e sub alpha
                    ev     variable emission in spectrum
                    FG     for F-G type stars
                    KM     for K-M type stars
                    T      characteristics of T Tauri stars

Alt_Var_Name
The alternative name of the suspected variable star either as given in the main Catalog of Galactic Variable Stars (the HEASARC GCVS table, created from the CDS table B/gcvs/gcvs_cat.dat), a Name-List number, if it starts with the 2-digit number 67-77 and is followed by the 4-digit number of the star in the corresponding Name List, or as given in the GCVS Catalog of Extragalactic Variable Stars (the HEASARC GCVSEGVARS table, created from the CDS table B/gcvs/evs_cat.dat). In the last case, the name may be followed by an asterisk: this indicates that there are remarks about this star in GCVS Volume V.

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 GCVSNSVARS database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Wednesday, 23-Nov-2022 19:34:33 EST