J/AJ/142/155 Variable stars photometry from Dome A (Wang+, 2011)
Photometry of variable stars from Dome A, Antarctica.
Wang L., Macri L.M., Krisciunas K., Wang L., Ashley M.C.B., Cui X.,
Feng L.-L., Gong X., Lawrence J.S., Liu Q., Luong-Van D., Pennypacker C.R.,
Shang Z., Storey J.W.V., Yang H., Yang J., Yuan X., York D.G., Zhou X.,
Zhu Z., Zhu Z.
<Astron. J., 142, 155 (2011)>
=2011AJ....142..155W 2011AJ....142..155W
ADC_Keywords: Stars, variable ; Photometry, SDSS
Keywords: site testing - stars: variables: general
Abstract:
Dome A on the Antarctic plateau is likely one of the best observing
sites on Earth thanks to the excellent atmospheric conditions present
at the site during the long polar winter night. We present
high-cadence time-series aperture photometry of 10000 stars with
i<14.5mag located in a 23deg2 region centered on the south celestial
pole. The photometry was obtained with one of the CSTAR telescopes
during 128 days of the 2008 Antarctic winter. We used this photometric
data set to derive site statistics for Dome A and to search for
variable stars. Thanks to the nearly uninterrupted synoptic coverage,
we found six times as many variables as previous surveys with similar
magnitude limits. We detected 157 variable stars, of which 55% were
unclassified, 27% were likely binaries, and 17% were likely pulsating
stars. The latter category includes δ Scuti, γ Doradus,
and RR Lyrae variables. One variable may be a transiting exoplanet.
Description:
An observatory that can operate year round without interruptions is
required to best capitalize upon the advantages provided by the
Antarctic plateau. We have built such an observatory at Dome A, called
PLATO (PLATeau Observatory), and a quad-telescope called CSTAR (the
Chinese Small Telescope ARray). Observations were conducted from 2008
March 20 through 2008 July 27; during this interval, more than 287800
frames were acquired with a total integration time of 1615hr. The
total amount of raw data collected during the observing season was
about 350GB. Two groups have carried out independent analyses of the
data; one at the National Astronomical Observatories of the Chinese
Academy of Sciences (Zhou et al. 2010PASP..122..347Z 2010PASP..122..347Z) and another at
Texas A&M University and Beijing Normal University (present work).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 83 157 Variable stars observed
table6.dat 36 639 Fourier analysis of variable star candidates
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2012)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
J/ApJS/188/473 : Chandra variable guide star catalog (Nichols+, 2010)
J/A+A/499/967 : Long-term monitoring of γ Dor stars (Cuypers+, 2009)
J/ApJ/598/597 : Frequency analysis of RR Lyrae (Alcock+, 2003)
J/AJ/115/1016 : M31B eclipsing binaries and Cepheids (Kaluzny+ 1998)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [572/136863] CSTAR identification
8- 17 A10 --- GSC2.3 Identification from Guide Star Catalog (1)
19- 20 I2 h RAh Hour of Right Ascension from GSC2.3 (J2000) (2)
22- 23 I2 min RAm Minute of Right Ascension from GSC2.3 (J2000)
25- 29 F5.2 s RAs Second of Right Ascension from GSC2.3 (J2000)
31 A1 --- DE- [-] Declination sign from GSC2.3 (J2000) (2)
32- 33 I2 deg DEd Degree of Declination from GSC2.3 (J2000)
35- 36 I2 arcmin DEm Arcminute of Declination from GSC2.3 (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of Declination from GSC2.3 (J2000)
43- 47 F5.2 mag imag CSTAR mean i band magnitude
49- 57 F9.6 d Per ? Main period
59- 61 A3 --- n_Per Source of period determination (3)
63- 69 F7.4 d T0 ? Epoch of minimum light (JD-2454500) (4)
71- 83 A13 --- Type Tentative classification of variable type (5)
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Note (1): The Guide Star Catalog, version 2.3.2 (GSC2.3, Cat. I/305).
The GSC2.3 identification differs from GSC2.2 preliminary version: 10
characters, the first four representing the level-6 HTM (Hierarchical
Triangular Mesh) coded in base 36 (0..9 and A..Z), and the last 6
represent a zero-filled sequence number assigned to each source upon
initial detection.
Note (2): If the star is not in GSC2.3, the position is based on the CSTAR
master image.
Note (3): Code as follows:
LS = Lomb-Scargle method (Lomb 1976Ap&SS..39..447L 1976Ap&SS..39..447L; Scargle
1982ApJ...263..835S 1982ApJ...263..835S);
BLS = box fitting algorithm (Kovacs et al. 2002A&A...391..369K 2002A&A...391..369K);
P04 = Fourier decomposition with Period04 program (Lenz & Breger
2005CoAst.146...53L 2005CoAst.146...53L).
See section 5.1 for further explanations.
Note (4): Of primary eclipse or minimum light (JD-2454500), when applicable.
Note (5): Code as follows:
[A] = variable from All Sky Automated Survey;
[G] = variable from the General Catalog of Variable Stars (Cat. B/gcvs);
CW-FO = W Virginis variable, first-overtone pulsator;
DCEP-FU = Delta Cephei variable,fundamental-mode pulsator;
DSCT = Delta Scuti variable;
EC = contact binary;
ESD = semi-detached binary;
ED = detached binary;
GDOR = Gamma Doradus variable;
LT = long-term trend;
MISC/SR = Miscellaneous/semi-regular variable;
RRL = RR Lyrae variable.
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- ID [572/133742] CSTAR identification
8- 17 F10.6 d-1 Freq Frequency; in units of cycle/day
19- 24 F6.2 mmag Amp [0.23/281.91] amplitude of the peak
26- 30 F5.2 --- S/N Signal-to-noise ratio of each peak
32- 36 A5 --- Notes Relations between primary and other frequencies (1)
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Note (1): We searched for multiple periods in the time-series photometry of the
variables using the Period04 program (Lenz & Breger, 2005CoAst.146...53L 2005CoAst.146...53L).
We started by identifying the frequency (f1) that displayed the
highest S/N peak in the periodogram. Next we prewhitened the time
series (i.e., subtracted off the most significant frequency) and
searched for the next highest peak in the frequency spectrum. We
repeated the process until all peaks with S/N>4 were identified.
For example, consider the variable CSTAR#061353, shown in Figure 17.
There are three significant peaks in the periodogram, with
fi=44.2879, 44.1690, and 42.1209 cycles/day) and S/Ns of 15.8, 15.7,
and 15.0, respectively. See section 5.2.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 11-Mar-2013