J/PASP/126/521 UBVRIJHK photometry of RR Lyrae in M4 (Stetson+, 2014)
Optical and near-infrared UBVRIJHK photometry for the RR Lyrae stars in the
nearby globular cluster M 4 (NGC 6121).
Stetson P.B., Braga V.F., Dall'Ora M., Bono G., Buonanno R., Ferraro I.,
Iannicola G., Marengo M., Neeley J.
<Publ. Astron. Soc. Pac., 126, 521-543 (2014)>
=2014PASP..126..521S 2014PASP..126..521S
ADC_Keywords: Stars, variable ; Photometry, UBVRI ; Photometry, infrared
Keywords: Stars
Abstract:
We present optical and near-infrared UBVRIJHK photometry of stars in
the Galactic globular cluster M4 (NGC 6121) based upon a large corpus
of observations obtained mainly from public astronomical archives. We
concentrate on the RR Lyrae variable stars in the cluster, and make a
particular effort to accurately reidentify the previously discovered
variables. We have also discovered two new probable RR Lyrae variables
in the M4 field: one of them by its position on the sky and its
photometric properties is a probable member of the cluster, and the
second is a probable background (bulge?) object. We provide accurate
equatorial coordinates for all 47 stars identified as RR Lyraes, new
photometric measurements for 46 of them, and new period estimates for
45. We have also derived accurate positions and mean photometry for 34
more stars previously identified as variable stars of other types, and
for an additional five non-RR Lyrae variable stars identified for the
first time here. We present optical and near-infrared color-magnitude
diagrams for the cluster and show the locations of the variable stars
in them. We present the Bailey (period-amplitude) diagrams and the
period-frequency histogram for the RR Lyrae stars in M4 and compare
them to the corresponding diagrams for M5 (NGC 5904). We conclude that
the RR Lyrae populations in the two clusters are quite similar in all
the relevant properties that we have considered. The mean periods,
pulsation-mode ratios, and Bailey diagrams of these two clusters show
support for the recently proposed "Oosterhoff-neutral" classification.
Description:
Our optical observations of M4 consist of 5003 individual CCD images
obtained during the course of 18 observing runs between 1994 and 2010.
The infrared photometry for M4 consisted of 55 datasets from 18
observing runs between 2002 and 2012.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 68 47 Positions and periods for the RR Lyrae variables
in M4
table4.dat 77 47 Mean optical magnitudes and amplitudes for the
RR Lyraes in M4
table5.dat 55 47 Mean NIR Magnitudes and Amplitudes for the
RR Lyraes in M4
notes.dat 80 88 Individual notes on RR Lyrae variables
table6.dat 92 40 Positions and mean optical photometry for
other candidate variable stars
table7.dat 45 40 Mean infrared photometry for other candidate
variable stars
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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- 3 A3 --- ID Star designation (VNN or CN)
4 A1 --- n_ID [c] Missing data (1)
6- 7 I2 h RAh Right ascension (J2000.0)
9- 10 I2 min RAm Right ascension (J2000.0)
12- 16 F5.2 s RAs Right ascension (J2000.0)
18 A1 --- DE- Declination sign (J2000.0)
19- 20 I2 deg DEd Declination (J2000.0)
22- 23 I2 arcmin DEm Declination (J2000.0)
25- 28 F4.1 arcsec DEs Declination (J2000.0)
30- 35 F6.4 d Per1 ?=- Pulsation period from Clement et al.
(2001AJ....122.2587C 2001AJ....122.2587C) compilation
37- 46 F10.8 d Per2 ?=- Pulsation period based on our current data
using the string-length method (SL)
48- 57 F10.8 d Per3 ?=- Pulsation period based on our current data
using the Lomb-Scargle method (LS)
59- 68 F10.4 d T0 ?=- Epoch of maximum (HJD-2400000) (2)
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Note (1): We have no data of our own for this star. The astrometry is based
on measurements of three images from the Digitized Sky Survey, carefully
transformed to our coordinate system. This is the position of a fairly
isolated star of appropriate apparent brightness lying 0.7" from the
position given in Clement et al. (2001AJ....122.2587C 2001AJ....122.2587C). The light-curve
parameters are based on data from Cacciari (1979AJ.....84.1542C 1979AJ.....84.1542C).
Note (2): estimated from the analytical fit of the V-band light curve, except
V33 (T0 from Cacciari, 1979AJ.....84.1542C 1979AJ.....84.1542C) and V34 from de Sitter
(1947BAN....10..287D 1947BAN....10..287D)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Star designation
4 A1 --- n_Per [ef] Note on Period (G1)
6- 15 F10.8 d Per Pulsation period based on the LS method
18- 22 F5.2 mag Umag Mean U magnitude (4)
24- 28 F5.2 mag Bmag Mean B magnitude (4)
30- 34 F5.2 mag Vmag Mean V magnitude (4)
36- 40 F5.2 mag Rmag ?=- Mean R magnitude (4)
42- 46 F5.2 mag Imag ?=- Mean I magnitude (4)
48- 51 F4.2 mag Uamp ?=- Luminosity amplitude in U band (5)
53- 56 F4.2 mag Bamp ?=- Luminosity amplitude in B band (5)
58- 61 F4.2 mag Vamp ?=- Luminosity amplitude in V band (5)
63- 66 F4.2 mag Ramp ?=- Luminosity amplitude in R band (5)
68- 71 F4.2 mag Iamp ?=- Luminosity amplitude in I band (5)
73- 76 A4 --- Type Type of RR Lyrae (RRab or RRc) (6)
77 A1 --- n_Type [*] * for variables that are candidate
Blazhko variables
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Note (4): Mean U, B, V, R, I magnitudes. The mean was computed as an intensity
mean and then transformed into magnitude.
Note (5): Luminosity amplitudes in U, B, V, R, I. The amplitudes were estimated
as the difference between minimum and maximum of the analytical fit. The U
amplitude is only available for a few variables (see Appendix A).
Note (6): Pulsation mode: RRab, fundamental; RRc, first overtone.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Star designation
4 A1 --- n_Per [eg] Note on ID (G1)
6- 15 F10.8 d Per Pulsation period based on the LS method
18- 22 F5.2 mag Jmag ?=- Mean J magnitude (2)
24- 28 F5.2 mag Hmag ?=- Mean H magnitude (2)
30- 34 F5.2 mag Kmag ?=- Mean K magnitude (2)
36- 39 F4.2 mag Jamp ?=- Luminosity amplitude in J band (3)
41- 44 F4.2 mag Hamp ?=- Luminosity amplitude in H band (3)
46- 49 F4.2 mag Kamp ?=- Luminosity amplitude in K band (3)
51- 54 A4 --- Type Type of RR Lyrae (4)
55 A1 --- n_Type [*] * for variables that are candidate Blazhko
variables
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Note (2): Mean J, H, K magnitudes. The mean was computed as an intensity mean
and then transformed into magnitude.
Note (3): Luminosity amplitudes in J, H, K. The amplitudes were estimated as the
difference between minimum and maximum of the analytical fit.
Note (4): Pulsation mode: RRab, fundamental; RRc, first overtone.
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Star designation (VNN or CN)
5- 80 A76 --- Note Text of the note
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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- 3 A3 --- ID Star designation (VNN, KNN or CN)
4 A1 --- n_ID [*] Note on K58 (1)
5- 7 A3 --- OName Other name (G2)
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 31 F4.1 arcsec DEs Declination (J2000)
33- 37 F5.2 mag Umag ? Mean U magnitude
39- 43 F5.2 mag Bmag ? Mean B magnitude
45- 49 F5.2 mag Vmag ? Mean V magnitude
51- 55 F5.2 mag Rmag ?=- Mean R magnitude
57- 61 F5.2 mag Imag ? Mean I magnitude
63- 73 F11.8 d Per ? Period
74 A1 --- n_Per [a] Note on Per (2)
76- 92 A17 --- Com6 Comments on optical photometry
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Note (1): *: K58 originaly not in table6.dat, added here with position from
Kaluzny et al. 2013AcA....63..181K 2013AcA....63..181K, without other data
Note (2): a: Because of the haphazard cadence of our observations, this star is
subject to extreme aliasing problems. Left to ourselves, we would not have
been able to determine a secure period. Kaluzny et al. 2013 (J/AJ/145/43)
give the period of this star as 48.19days, and this is the best period we
were able to find between 48.1 and 48.3days. Many other periods outside this
range would be possible if our data were all that were available.
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- ID Star designation
5- 7 A3 --- OName Other name (G2)
10- 14 F5.2 mag Jmag Mean J magnitude
16- 20 F5.2 mag Hmag Mean H magnitude
22- 26 F5.2 mag Kmag Mean K magnitude
28- 45 A18 --- Com7 Comments on IR photometry
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Global notes:
Note (G1): Notes as follows:
e = The period is the one given in the compilation of Clement et al.
(2001AJ....122.2587C 2001AJ....122.2587C). The tabulated magnitudes based on robust means of
our data; we have insufficient data to fit a light curve.
f = Tabulated results based on published data from Cacciari
(1979AJ.....84.1542C 1979AJ.....84.1542C); the star lies outside our field.
g = Outside our field of view (for IR data)
Note (G2): Alternative name from Kaluzny et al. (1997AJ....113.2219K 1997AJ....113.2219K) or
Mochejska et al. (2002AJ....124.1486M 2002AJ....124.1486M), which translates in <[KTK97] VNN>
(Nos V44-V55) or <[MKT2002] VNN> (Nos V56-V57) respectively in Simbad.
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History:
From electronic version of the journal
References:
Braga et al., Paper I 2015ApJ...799..165B 2015ApJ...799..165B
Neeley et al., Paper II 2015ApJ...808...11N 2015ApJ...808...11N, Cat. J/ApJ/808/11
Braga et al., Paper IV. 2016AJ....152..170B 2016AJ....152..170B, Cat. J/AJ/152/170
Braga et al., Paper V. 2018AJ....155..137B 2018AJ....155..137B
(End) Patricia Vannier [CDS] 06-Nov-2014