of Lomonosov Moscow State University,
Russia

General Catalogue of Variable Stars



The draft classification (version August 9, 2006) for new GCVS versions
IAU XXVIth General Assembly,
Prague, 2006

Samus N.N.
Moscow, the GCVS team


Along with the "+" sign (coexistence of two types), it is suggested to introduce the "|" sign (meaning "or") for classification options for the same object, e.g. EC|Ell, EC|RR.

Pulsating variables

Present:Suggested:
ACYG ACyg
BCEP, BCEPS BCep (BCEPS, after Jakate, seem not justified)
CEP Cep
DCEP, DCEPS, CEP(B) DCep, DCep0, DCep1, DCepB01, DCepB12
Remark: 0 fundamental, 1 1st overtone, 01 fundamental plus overtone, 12 1st and 2nd overtones. For non-beat Cepheids, it is safer not to indicate the mode yet
CW, CWA, CWB CW (period will also be given)
DSCT, DSCTC, SXPHE DSct (amplitude will also be given, population membership is not always obvious)
L, LB, LC L, Lb (for red stars)
M M
PVTEL PVTel
RR, RRAB, RRC, RR(B) RR, RR0, RR1, RRB01
RV, RVA, RVB RV, RVb (if the secondary wave's amplitude is at least equal to that of the main oscillation)
SR, SRA, SRB, SRC, SRS SR (the regularity level should be indicated by the presentation of the light elements; if a star is a supergiant, it will be obvious from its spectral type)
SRD SRd (we feel not inclined to introduce the UU Her type)
ZZ, ZZA, ZZB, ZZO ZZ (subtype is contained in the spectral type)
BLBOO BLBoo
GDOR GDor
RPHS RPHS (rapidly pulsating hot subdwarfs. We repeat our call for suggestions of a better designation).
LPB or LBV SPB

Eruptive variables
Present:Suggested:
FU, I, IA, IB, INA, INB, INT, IT, IN(YY), IS, ISA, ISB I, TT, TTc, TTw, HAeBe
Remark: I is for irregulars with doubts about their being young, TTc for classical and TTw, for weak-lined T Tauri stars, HAeBe for Herbig Ae/Be stars
GCAS, BE Be
RCB RCB
RS Move to rotating variables
SDOR SDor
UV, UVN UV
WR WR
New type: PP (a proto-planetary object)
New type: dL (L dwarf), the causes of variability not quite clear yet

Rotating variables
Present:Suggested:
ACV, SXARI ACV
ACVO roAp, ACV+roAp
BY BY; also should include chromospherically active giants
ELL Ell
FKCOM FKCom
PSR Psr
R R
RS (earlier among eruptive)

Cataclysmic variables and other stars with outbursts
Present:Suggested:
No subtype: CV
N, NA, NB N, Nhf (final helium flash; suggestions of a different designation are welcome)
NR Nr, NSym (symbiotic Nova),
UGWZ (see below)
NC NSym
NL CV, UXUMa ("permanent outburst"), VY (VY Scl type, fadings from time to time)
SN, SNI, SNII SN (to avoid introducing the current complex classification)
AM AM (including XM from X-ray variables), DQ (intermediate polars)
UG, UGSS, UGZ UG, UGSS, UGZ
UGSU UGSU, UGWZ (WZ Sge type, extremely long supercycles, large amplitudes), UG_ER (ER UMa type, short supercycles and normal cycles, small amplitudes; ideas of a better abbreviation are welcome)
ZAND Sym, NSym

Eclipsing variables (the description of the class should not mention close binarity)
Present:Suggested:
E, EA, EB, EW, EP E, EA, EC contact
(merging EB and EW), EP
PN, WD, WR Remove from the classification, indicate through the spectral type or Remarks
RS If such a star has eclipses, give notation like EA+RS, RS+EA
AR, D, DM, DS, DW, K, KE, KW, SD Remove from the classification: as a rule, these types in the GCVS are based on indirect evidence

X-ray variables
Present:Suggested:
X, XB, XF, XI, XJ, XND, XNG, XP, XPR, XPRM, XM AM (move to cataclysmics), X, XN, XNB (approximately corresponds to XNG, a B star orbiting a compact object), Xlm (low mass), Xhm (high mass), Xmq (microquasars). In this class, advice from experts is especially needed.