J/AJ/118/453 M9 RR Lyrae CCD observations (Clement+, 1999)
New CCD observations of the RR Lyrae variables in the Oosterhoff type II
cluster M9.
Clement C.M., Shelton I.
<Astron. J., 118, 453-461 (1999)>
=1999AJ....118..453C 1999AJ....118..453C
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, CCD
Keywords: globular clusters: general - RR Lyrae variable -
stars: fundamental parameters - stars: horizontal-branch -
stars: oscillations
Abstract:
CCD observations have been used to study 16 of the previously known
variables in the Oosterhoff type II globular cluster M9. The
properties of the RR Lyrae variables in M9 are compared with those in
the Oosterhoff type I cluster M3. Methods devised by Simon, Jurcsik, &
Kovacs have been used to derive physical parameters for the stars
from Fourier analysis. The mean metal abundance so derived for M9,
[Fe/H]=-1.77, is in good agreement with the metal abundance derived
from spectroscopic observations. All methods for calculating the
absolute magnitudes of RR Lyrae variables from Fourier coefficients
indicate that the RR Lyrae variables in M9 are more luminous than
those in M3. However, there are three RR Lyrae stars in M3 that may be
as bright as the M9 stars. These three are thought to be in a more
advanced evolutionary state than the other M3 RR Lyrae stars. Absolute
magnitudes have also been derived for the RR Lyrae stars in M68 and
M107. The different methods predict that RR Lyrae stars in metal-poor
clusters are more luminous than those in more metal-rich clusters, but
there are inconsistencies in the relative luminosities derived by the
different methods.
Description:
Time-series V CCD photometry for the 16 RR Lyrae stars in the globular
cluster M9.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 46 16 Elements of the variable stars
table1.dat 125 165 Time-series CCD V photometry of 16 RR Lyrae stars
in Messier 9 (NGC 6333)
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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- 3 A3 --- Seq Sequential number of the variable (VNN),
<Cl* NGC 6333 SAW VNN> in Simbad
5- 8 A4 --- Type Type of RR Lyrae
10- 13 I4 arcsec Xpos X position
15- 17 I3 arcsec Ypos Y position
19- 27 F9.7 d Per Period
29- 33 F5.3 mag AV ?=- Absorption in V band
35- 39 F5.3 mag e_AV ?=- rms uncertainty on AV
41- 46 F6.3 mag <Vmag> ?=- Mean V magnitude
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian day
14- 19 F6.3 mag V1mag ?=- V magnitude of V1
21- 26 F6.3 mag V2mag V magnitude of V2
28- 33 F6.3 mag V4mag ?=- V magnitude of V4
35- 40 F6.3 mag V5mag V magnitude of V5
42- 47 F6.3 mag V6mag ?=- V magnitude of V6
49- 54 F6.3 mag V7mag ?=- V magnitude of V7
56- 61 F6.3 mag V10mag ?=- V magnitude of V10
63- 69 F7.4 mag V11mag ?=- V magnitude of V11
71- 76 F6.3 mag V14mag V magnitude of V14
78- 83 F6.3 mag V15mag ?=- V magnitude of V15
85- 90 F6.3 mag V16mag ?=- V magnitude of V16
92- 97 F6.3 mag V17mag ?=- V magnitude of V17
99-104 F6.3 mag V18mag ?=- V magnitude of V18
106-111 F6.3 mag V19mag ?=- V magnitude of V19
113-118 F6.3 mag V20mag ?=- V magnitude of V20
120-125 F6.3 mag V21mag ?=- V magnitude of V21
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Acknowledgements:
Armando Arellano Ferro, armando(at)astro.unam.mx,
Instituto de Astronomia, UNAM, Mexico
References:
(End) A. Arellano Ferro [Inst. Astron., UNAM], P. Vannier [CDS] 25-Feb-2013