J/A+A/562/A125 OGLE-III SMC massive stars VI light curves (Kourniotis+, 2014)
Variability of massive stars with known spectral types in the Small Magellanic
Cloud using 8 years of OGLE-III data.
Kourniotis M., Bonanos A.Z., Soszynski I., Poleski R., Krikelis G.,
Udalski A., Szymanski M.K., Kubiak M., Pietrzynski G., Wyrzykowski L.,
Ulaczyk K., Kozlowski S., Pietrukowicz P.
<Astron. Astrophys. 562, A125 (2014)>
=2014A&A...562A.125K 2014A&A...562A.125K
ADC_Keywords: Magellanic Clouds ; Binaries, eclipsing ; Stars, Be ;
Stars, variable
Keywords: binaries: eclipsing - galaxies: individual: SMC - stars: early-type -
stars: variables: general - stars: massive - stars: emission-line, Be
Abstract:
We present a variability study of 4646 massive stars in the Small
Magellanic Cloud (SMC) with known spectral types from the catalog of
Bonanos et al. (2010, Cat. J/AJ/140/416) using the light curves from
the OGLE-III database. The goal is to exploit the time domain
information available through OGLE-III to gain insight into the
processes that govern the evolution of massive stars. This variability
survey of massive stars with known spectral types is larger than any
previous survey by a factor of 7. We find that 60% of our sample (2766
stars) show no significant variability and 40% (1880 stars) exhibit
variability distributed as follows: 807 stars display low-amplitude
stochastic variability with fluctuations in I-band of up to 0.05mag,
443 stars present irregular variability of higher amplitude (76% of
these are reported as variables for the first time), 205 are eclipsing
binaries (including 101 newly discovered systems), 50 are candidate
rotating variables, 126 are classical Cepheids, 188 stars exhibit
short-term sinusoidal periodicity (P<3-days) making them candidate
'slowly pulsating B stars' and non-radial Be pulsators, and 61
periodic stars exhibit longer periods. We demonstrate the wealth of
information provided in the time domain, by doubling the number of
known massive eclipsing binary systems and identifying 189 new
candidate early-type Be and 20 Oe stars in the SMC. In addition, we
find that ∼80% of Be stars are photometrically variable in the
OGLE-III time domain and provide evidence that short-term pulsating
stars with additional photometric variability are rotating close to
their break-up velocity.
Description:
We used the photometry provided by the OGLE-III monitoring survey to
study the variability of 4646 massive stars with known spectral types
in the SMC. Based on the standard deviation of the light curves, we
classified the stars into constant, low-amplitude and high amplitude
variables. We searched the low- and high-amplitude variables for
periodic signals using the Analysis of Variance method
(Schwarzenberg-Czerny, 1989MNRAS.241..153S 1989MNRAS.241..153S). The following tables
present newly discovered and known EBs, ellipsoidal variables,
Cepheids and other periodic stars. We also present the irregular
variables, which have stochastic, high-amplitude variability.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 153 101 Newly discovered eclipsing binaries in the SMC
table2.dat 144 104 Known eclipsing binaries in the SMC
table3.dat 145 50 Candidate rotating variables in the SMC
table4.dat 135 126 Known Cepheids in the SMC
table5.dat 145 138 Short periodic SMC stars
table6.dat 123 50 Short periodic SMC stars with extra variability
table7.dat 158 45 Long periodic SMC stars
table8.dat 128 16 Long periodic SMC stars with extra variability
table9.dat 154 443 Irregular variables in the SMC
table10.dat 40 805302 Light curves of the variables
lc/* . 1073 Individual light curves (1 file per variable)
refs.dat 63 15 Reference
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See also:
J/AJ/140/416 : IR photometry of massive stars in the SMC (Bonanos+, 2010)
J/AcA/60/17 : SMC classical Cepheids VI light curves (Soszynski+, 2010)
J/AcA/60/91 : SMC type II Cepheids VI light curves (Soszynski+, 2010)
J/AcA/60/165 : SMC RR Lyrae VI light curves (Soszynski+, 2010)
J/AcA/61/217 : SMC long-period variables VI light curves (Soszynski+ 2011)
J/MNRAS/415/1366 : OGLE RR Lyrae in SMC (Kapakos+, 2011)
Byte-by-byte Description of file: table1.dat table2.dat table4.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Record number within the original table
5- 44 A40 --- Name(s) Other star name(s), semi-colon (;) separated
45- 60 A16 --- SpType MK Spectral Type
62- 70 F9.6 deg RAdeg Right ascension, equinox J2000.0
72- 80 F9.5 deg DEdeg Declination, equinox J2000.0
82- 87 F6.3 --- Skew Value of Skewness
89- 94 F6.3 --- Kurt Value of Kurtosis
96-109 A14 --- OGLEIII OGLE-III field & database number
111-115 F5.2 mag Imag Mean magnitude (apparent) in I filter
117-121 F5.2 mag Vmag ?=99.99 Mean magnitude (apparent) in V filter
123-125 A3 --- Ref Reference, in refs.dat file
127-136 F10.6 d Per Period
138-153 A16 --- Note Notes (G1)
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Byte-by-byte Description of file: table[35678].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq Record number within the original table
5- 47 A43 --- Name(s) Other star name(s), semi-colon (;) separated
50- 61 A12 --- SpType MK Spectral Type
63- 71 F9.6 deg RAdeg Right ascension, equinox J2000.0
73- 81 F9.5 deg DEdeg Declination, equinox J2000.0
83- 96 A14 --- OGLEIII OGLE-III field & database number
98-102 F5.2 mag Imag Mean magnitude (apparent) in I filter
104-108 F5.2 mag Vmag Mean magnitude (apparent) in V filter
110-119 F10.6 d Per Period
121-128 A8 --- Ref Reference, in refs.dat file
130-158 A29 --- Note Note (G1)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq Record number within the original table
5- 56 A52 --- Name(s) Other star name(s), semi-colon (;) separated
58- 76 A19 --- SpType MK Spectral Type
78- 86 F9.6 deg RAdeg Right ascension, equinox J2000.0
88- 96 F9.5 deg DEdeg Declination, equinox J2000.0
98-111 A14 --- OGLEIII OGLE-III field & database number
113-117 F5.2 mag Imag Mean magnitude (apparent) in I filter
119-123 F5.2 mag Vmag ?=99.99 Mean magnitude (apparent) in V filter
125-129 F5.3 mag s_Imag Standard Deviation σI
131-138 A8 --- Ref Reference, in refs.dat file
140-154 A15 --- Note Note (G1)
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- OGLEIII OGLE-III Field and Database Number
16 A1 --- Filter [IV] Filter passband (G2)
18- 27 F10.5 d Obs.Date Heliocentric Julian date (HJD-2450000)
29- 34 F6.3 mag mag Magnitude in Filter
36- 40 F5.3 mag e_mag Uncertainty in magnitude
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Byte-by-byte Description of file (# headlines): lc/*
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Bytes Format Units Label Explanations
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1 A1 --- Filter [IV] Filter passband (G2)
3- 12 F10.5 d Obs.Date Heliocentric Julian date (HJD-2450000)
14- 19 F6.3 mag mag Magnitude in Filter
21- 25 F5.3 mag e_mag Uncertainty in magnitude
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Ref Reference code
5- 23 A19 --- BibCode BibCode
25- 42 A18 --- Aut Author's name
44- 63 A20 --- Com Comments
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Global Notes:
Note (G1): Keys in notes are:
* = Hunter et al. (in preparation)
** = Evans et al. (2006A&A...456..623E 2006A&A...456..623E)
*** = Martayan et al. (2007A&A...472..577M 2007A&A...472..577M)
SAT = Possible Saturation Noise
CON = Possible Constant Star
FOR = Possible Foreground Star
AM = Apsidal Motion
BCEP = Candidate β Cephei
DPV = Double-Periodic Variable
TEB(a) = Transient Eclipsing Binary. Period corresponds to HJD range
2452000-2454200
TEB(b) = Transient Eclipsing Binary. Additional transient EB with
P=5.242314 days, in the HJD range 2453200-2453800
Note (G2): Filter passband:
I = Cousins I-band magnitude
V = Johnson V-band magnitude
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Acknowledgements:
M. Kourniotis, mkourniotis(at)astro.noa.gr,
IAASARS, National Observatory of Athens, Greece
(End) M. Kourniotis [IAASAR, Greece], Patricia Vannier [CDS] 08-Jan-2014