J/AJ/135/1459 Period of M15 variable stars (Corwin+, 2008)
The globular cluster M15.
I. Identification, discovery, and period determination of variable stars.
Corwin T.M., Borissova J., Stetson P.B., Catelan M., Smith H.A., Kurtev R.,
Stephens A.W.
<Astron. J., 135, 1459-1473 (2008)>
=2008AJ....135.1459C 2008AJ....135.1459C
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, UBVRI
Keywords: globular clusters: individual (M15) - stars: evolution -
stars: variables: other
Abstract:
We present new BVI CCD photometry for variables in the globular
cluster M15. Our photometry was obtained using both the image
subtraction package ISIS and DAOPHOT/ALLFRAME. The data were acquired
in 2001 on two observing runs on 11 observing nights using the 2m
telescope of the Bulgarian National Astronomical Observatory "Rozhen"
with a Photometrics CCD camera. For 39 previously known variables, we
present a period for the first time, and improved periods were
obtained for many previously known variables. Fourteen new variables
are reported. We present updated Bailey diagrams for the cluster, and
discuss its Oosterhoff classification. Although many of M15's RRab
pulsators fall at an intermediate locus between Oosterhoff types I and
II (OoII) in the Bailey diagram, we argue that M15 is indeed a bona
fide OoII globular cluster.
Description:
Time-series photometry was obtained during the interval 2001 July 13
to 2001 July 19 with the 2m Ritchey-Chretien telescope of the
Bulgarian National Astronomical Observatory "Rozhen" with a
Photometrics CCD camera. This represents almost all of our data.
During the interval 2001 September 18 to 2001 September 25, using the
same telescope and instrument, a few additional images were obtained.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 148 M15 variables, new periods
table2.dat 45 98 M15 variables, positions relative to cluster center
table3.dat 67 111 M15 variables, VBI photometry
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See also:
J/AJ/110/704 : RR Lyrae Variables in M15 (Silbermann+ 1995)
J/AJ/124/3255 : UBV photometry in M15 (van der Marel+, 2002)
J/other/RMxAA/42.75 : M15 RR Lyrae CCD RV light curve (Arellano Ferro+, 2006)
J/ApJ/670/379 : UV photometry of M15 (Dieball+, 2007)
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 Variable name (G1)
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 29 F4.1 arcsec DEs Declination (J2000)
31- 40 F10.7 d Per.p ? Previous period
42- 50 F9.7 d Per ? Our period
51 A1 --- u_Per [?] Uncertainty flag on Per
53- 58 A6 --- Type Variable type
61 A1 --- --- [=]
62- 65 A4 --- OName Other name (VNNN)
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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 Variable name (G1)
7- 12 F6.2 arcsec Xpos.p Previous X position
14- 20 F7.2 arcsec Ypos.p Previous Y position
22- 27 F6.2 arcsec Xpos Our X position
29- 35 F7.2 arcsec Ypos Our Y position
37- 40 A4 --- OName Other name (VNNN, ZKNN, Phe)
42- 45 F4.2 arcsec Diff Difference
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Name Variable name (G1)
6 A1 --- --- [=]
7- 10 A4 --- OName Other name (ZKNN)
12- 17 F6.3 mag <Vmag> ? Mean V magnitude
19- 24 F6.3 mag <Vint> ? Intensity-averaged V magnitude
26- 29 F4.2 mag Vamp ? Amplitude in V band
31- 36 F6.3 mag <Bmag> ? Mean B magnitude
38- 43 F6.3 mag <Bint> ? Intensity-averaged B magnitude
45- 48 F4.2 mag Bamp ? Amplitude in B band
50- 55 F6.3 mag <Imag> ? Mean I magnitude
57- 62 F6.3 mag <Iint> ? Intensity-averaged I magnitude
64- 67 F4.2 mag Iamp ? Amplitude in I band
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Global notes:
Note (G1): Variable identified in Simbad as :
<Cl* NGC 7078 SAW VNNN> for VNNN,
<Cl* NGC 7078 ZK NN> for ZK NN,
<Cl* NGC 7078 CBS NN> for NVNN.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 12-Oct-2010