E. V. Kazarovets

GENERAL CATALOGUE OF VARIABLE STARS

The General Catalogue of Variable Stars (GCVS) is a large-scale project undertaken in Moscow since 1946 on behalf of the IAU. After a brief outline of its history, we discuss current problems of variable star catalogues and present our plans for the nearest future, including determination of accurate coordinates for all GCVS stars, new Name-lists, improvements of the classification scheme, etc.

General catalogue of variable stars: Version GCVS 5.1

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 Catalogue of Variable Stars (GCVS). This paper describes the requirements for the contents of the 5th edition and the current state of the catalog in its new version, GCVS 5.1. The complete revision of information for variable stars in the constellation Carina and the compilation of the 81st Name-list of Variable Stars are considered as examples of work on the 5th edition. The GCVS 5.1 is freely accessible on the Internet. We recommend the present paper as a unified reference to the 5th edition of the GCVS.

A Catalog of Variable Stars based on the new name list

We present a new electronic version of the General Catalog of Variable Stars (GCVS) based on the new IAU name list of confirmed variable stars. The catalog contains 1270 stars, most of them contained earlier in the New Catalog of Suspected Variable Stars or its supplement. A number of recent studies—including those by authors of the catalog, who investigated many stars using data from modern automatic surveys, determined light-curve elements for periodic stars, and plotted numerous light curves—have made it possible to move these stars to the GCVS. Among the catalog objects, 24 stars are novae or other unusual variable stars that acquired their GCVS names out of the usual order, upon communication from the Bureau of Astronomical Telegrams of the International Astronomical Union. We present the GCVS names, coordinates, classifications (in two forms: the GCVS system and a new, proposed system), brightness-variation limits, and light-curve elements for the catalog stars, as well as bibliographic references and remarks when necessary. We discuss several catalog stars that are of astrophysical interest or caused problems during the compilation of the catalog.

The Fifth Edition of the General Catalogue of Variable Stars: experiences in the constellation Centaurus

We have recently announced that the General Catalogue of Variable Stars enters the stage of its fifth, purely electronic edition (GCVS 5.1). We have included 1408 variable stars in the constellation Centaurus in this new version, GCVS 5.1. Working on this revision, we applied current possibilities from data mining, suggested new variability types for many variable stars and found new light elements for a large number of periodic variables. This paper describes the work completed during the preparation of GCVS 5.1 for Centaurus and discusses in detail a number of the most astrophysically significant cases.

Catalogs of variable stars, current and future

To study effects of stellar variability, it is necessary to have complete lists of variable stars with good coordinates, correct variability ranges, reliable classification. The General Catalogue of Variable Stars (GCVS) is one of the main sources of information of this kind. Recently, the flow of information on stellar variability has increased strongly, requiring new approaches to GCVS compilation. New classification schemes are needed for variable stars, taking into account the development of our knowledge. We present information on the current state of the GCVS, its web data base, new Name-Lists containing thousands of new variables. We also discuss the problems of developing a new classification system for variable stars, of implementing catalogs of variable stars based on automatic surveys into the GCVS, of cooperation and interaction between the GCVS and other important sources of information on variable stars.

GCVS problems with flare stars

These examples clearly show the importance of good finding charts for flare star identifications. Though continuously emphasized by IAU Comm. 27, the situation does not improve noticeably. Flare stars without finding charts constitute 36% of all flare stars in the Name-lists Nos. 67–71, compared to 7% of RR Lyraes without finding charts in the same lists. We expect a drastical increase of the number of known variables due to discoveries with space-borne telescopes. This will make identifications and positional work the most laborious and important part of compiling variable star catalogues. Kind cooperation of flare star discoverers is quite necessary. We ask our colleagues to take some more effort and find improved positions, publish finding charts or, at least, GSC identifications. This will spare much more effort in subsequent work.