J/AJ/135/1350 Hot variable stars in NGC 330 (Schmidtke+, 2008)
Hot variable stars in the SMC cluster NGC 330.
Schmidtke P.C., Chobanian J.B., Cowley A.P.
<Astron. J., 135, 1350-1360 (2008)>
=2008AJ....135.1350S 2008AJ....135.1350S
ADC_Keywords: Photometry, UBVRI ; Stars, variable ; Stars, Be ;
Cross identifications ; Magellanic Clouds
Keywords: galaxies: star clusters - Magellanic Clouds -
stars: emission-line, Be - stars: variables: other
Abstract:
In a sample of 150 hot stars in NGC 330, a SMC cluster containing a
high fraction of Be stars, we searched for photometric variables using
OGLE II data. At least one third of all stars are variable, with 38
being periodic. We found 27 pulsators (λ Eri variables), six
eclipsing systems, two bursting sources, and several stars with
unusual photometric behavior. Pulsations are present in ∼30% of known
Be stars, and they are long lived, lasting more than a decade. The
strongest pulsators are associated with stars evolved from the main
sequence.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 150 Sample of stars in NGC 330
table2.dat 92 38 Photometric periods for stars in NGC 330
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See also:
J/A+AS/102/451 : Emission-line stars and PNe in the SMC (Meyssonnier+ 1993)
J/AJ/108/932 : Variable stars in the SMC cluster NGC 330 (Sebo+, 1994)
J/AcA/48/147 : OGLE SMC BVI photometry (Udalski+ 1998)
J/A+AS/134/489 : Be stars in MC young clusters (Keller+ 1999)
J/A+A/472/577 : NGC 330 Be stars and binaries (Martayan+, 2007)
http://ogledb.astrouw.edu.pl/~ogle/photdb/ : OGLE II photometric databases
web site
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Name except for 2 stars (G1)
7- 24 A18 --- XID Other identification(s) (G1)
26- 30 F5.2 mag Vmag V-band magnitude
32 A1 --- r_Vmag [d] Origin of Vmag (2)
34- 38 F5.2 mag B-V ?=- B-V color index
40 A1 --- r_B-V [ed] Origin of B-V (2)
42- 47 I6 --- OGLE OGLE II Number SMC-SC7 (
in Simbad)
48 A1 --- f_OGLE [fg] Flag on OGLE (3)
50- 55 F6.3 mag Imag I-band mean magnitude
58- 62 F5.3 mag Isig Standard deviation of the normalized light curve
64- 74 A11 --- Notes Note(s) on individual sources (4)
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Note (2): Flag as follows:
d = From Grebel et al. (1996A&A...311..470G 1996A&A...311..470G)
e = From Momany et al. (2001A&A...379..436M 2001A&A...379..436M)
Note (3): Flag as follows:
f = Same as OGLE SMC-SC7 206271
g = Same as OGLE SMC-SC7 206788
Note (4): Notes as follows:
1 = identified as a Be star by one or more authors;
2 = identified as a λ Eri variable (small-amplitude pulsator)
by Balona (1992MNRAS.256..425B 1992MNRAS.256..425B);
3 = studied by Martayan et al. (2007, Cat. J/A+A/472/577);
4 = see text for B224 and B317.
stats = Stars with SigI lying along the "non-variable" (lower) edge of
the relation sigI vs Imag were not analyzed for possible periods.
For those stars we only looked at the statistics of their photometry
(the standard deviation), but we made no full analysis for possible
periods. See section 3 for more details.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Name from Balona, 1992MNRAS.256..425B 1992MNRAS.256..425B, except
for 2 stars (G1)
7- 24 A18 --- XID Other identification(s) (G1)
26- 29 F4.1 mag Imag I-band mean magnitude (1)
31- 35 F5.3 mag Iamp I-band amplitude (1)
37 A1 --- f_Per1 Flag on Per1
38- 44 F7.3 d Per1 Photometric period
45 A1 --- u_Per1 Uncertainty flag on Per1
47- 53 F7.3 d Per2 ? 2d photometric period
54 A1 --- u_Per2 Uncertainty flag on Per2
56- 60 F5.3 d Per3 ? 3d photometric period
62- 64 A3 --- Var Variable type (NRP, ecl, bur) (2)
66 A1 --- f_Var [de] Flag on Vartype (3)
68- 92 A25 --- Comm Comments
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Note (1): Imag = approximate mean magnitude; DeltaI = amplitude of sine curve
fit or primary eclipse depth.
Note (2): Variable type as follows:
NRP = Nonradial pulsations;
ecl = eclipses;
bur = outbursts.
Note (3): Flag as follows:
d = Balona (1992MNRAS.256..425B 1992MNRAS.256..425B) and/or Sebo & Wood (1994,
Cat. J/AJ/108/932) noted this as an eclipsing binary
e = Alternatively, this source might be eclipsing with double
the period listed
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Global Notes:
Note (G1): Acronyms used:
B = Balona (1992MNRAS.256..425B 1992MNRAS.256..425B), <Cl* NGC 330 Bal NNNN> in Simbad;
G = Grebel et al. (1992A&A...254L...5G 1992A&A...254L...5G), <Cl* NGC 330 GRD a> in Simbad;
HV = Harvard Var., <SV* HV NNNNN> in Simbad;
K = Keller et al. (1999, Cat. J/A+AS/134/489),
<Cl* NGC 330 KWBBE NNNN> in Simbad;
MA = Meyssonnier & Azzopardi (1993, Cat. J/A+AS/102/451),
<[MA93] NNNN> in Simbad;
Rob = Robertson (1974A&AS...15..261R 1974A&AS...15..261R), <Cl* NGC 330 Rob ANN> in Simbad;
SW = Sebo & Wood (1994, Cat. J/AJ/108/932), <Cl* NGC 330 SW NNNN> in Simbad.
History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 06-Sep-2010