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J/MNRAS/420/1333 NGC 5024 (M53) RR Lyrae VI light curves (Arellano Ferro+, 2012)

The unusually large population of Blazhko variables in the globular cluster NGC 5024 (M53). Arellano Ferro A., Bramich D.M., Figuera Jaimes R., Giridhar S., Kuppuswamy K. <Mon. Not. R. Astron. Soc., 420, 1333-1346 (2012)> =2012MNRAS.420.1333A
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, UBVRI Keywords: stars: variables: RR Lyrae, globular clusters: individual: NGC 5024 Abstract: We report the discovery of amplitude and phase modulations typical of the Blazhko effect in 22 RRc and nine RRab type RR Lyrae stars in NGC 5024 (M53). This brings the confirmed Blazhko variables in this cluster to 23 RRc and 11 RRab stars, which represent 66 and 37 per cent of the total population of RRc and RRab stars in the cluster, respectively, making NGC 5024 the globular cluster with the largest presently known population of Blazhko RRc stars. We place a lower limit of 52 per cent on the overall incidence rate of the Blazhko effect among the RR Lyrae population in this cluster. New data have allowed us to refine the pulsation periods. The limitations imposed by the time span and sampling of our data prevent reliable estimations of the modulation periods. The amplitudes of the modulations range between 0.02 and 0.39mag. The RRab and RRc are neatly separated in the colour-magnitude diagram, and the RRc Blazhko variables are on average redder than their stable counterparts; these two facts may support the hypothesis that the horizontal branch (HB) evolution in this cluster is towards the red and that the Blazhko modulations in the RRc stars are connected with the pulsation mode switch. Description: Time-series V and I photometry for all the RR Lyrae stars in our field of view. We list standard and instrumental magnitudes and their uncertainties corresponding to the variable star identification, filter, and epoch of mid-exposure. For completeness, we also list the reference flux, difference flux, and photometric scale factor, along with the uncertainties on the reference and difference fluxes. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 31 55 Periods and epochs of the RR Lyrae stars in NGC 5024 in our field of view table1.dat 78 13173 Time series V and I photometry for all the RR Lyrae stars in our field of view table6.dat 28 248 Phase and magnitude at the time of maximum brightness in the V band for a group of stars with Blazhko modulations
See also: J/AJ/116/1775 : BV photometry of M53 (Rey+, 1998) J/PAZh/23/454 : Identification and coordinates in M 53 (Evstigneeva+, 1997) J/A+A/358/547 : M53 variable stars V light curves (Kopacki, 2000) J/A+A/507/803 : VI photometry of new M53 variables (Dekany+, 2009) J/MNRAS/416/2265 : Variable stars in NGC 5024 (M53) (Arellano+, 2011) J/MNRAS/424/2722 : Variable stars in NGC 5024 (M53) (Bramich+, 2012) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 3 A3 --- VName Variable star name, <Cl* NGC 5024 SAW VNN> in Simbad 4 A1 --- n_VName [*] Flux contamination (1) 6- 12 A7 --- Type Bailey's type (2) 14- 21 F8.6 d Per Period 23- 31 F9.3 d HJDmax Maximum brightness HJD (HJD-2400000)
Note (1): V52 and V53 lie in close spatial proximity and it is possible that flux contamination between the variables is at least a partial cause of the observed Blazhko effect. Note (2): Bl: Blazhko variables with the SB-index larger than 145.
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 A3 --- VName Variable star name 5 A1 --- Filter [VI] Observation filter 7- 19 F13.5 d HJD Heliocentric Julian date at mid-exposure 21- 26 F6.3 mag magst Standard magnitude 28- 33 F6.3 mag maginst Instrumental magnitude 35- 39 F5.3 mag e_maginst Magnitude uncertainty (standard or instrumental) 41- 48 F8.3 s-1 Fref Reference flux (in ADU/s unit) (1) 50- 54 F5.3 s-1 e_Fref Reference flux uncertainty (in ADU/s unit) 56- 64 F9.3 s-1 DFlux Difference flux (in ADU/s unit) (1) 66- 71 F6.3 s-1 e_DFlux Difference flux uncertainty (in ADU/s unit) 73- 78 F6.4 --- p Photometric scale factor (1)
Note (1): Light curves for each star were constructed by calculating the total flux ftot(t) in adu/s at each epoch t from ftot(t)=fref+fdiff(t)/p(t) where fref is the reference flux (adu/s), fdiff(t) is the differential flux (adu/s) and p(t) is the photometric scalefactor (the integral of the kernel solution) Conversion to instrumental magnitudes was achieved using mins(t)=25.0-2.5log(ftot(t)) where mins(t) is the instrumental magnitude of the star at time t. Uncertainties were propagated in the correct analytical fashion.
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 3 A3 --- VName Variable star name 5- 10 F6.3 --- phimax [0/1] Phase at maximum brightness 12- 17 F6.3 mag Vmax V magnitude at maximum brightness 19- 28 F10.5 d HJDmax Maximum brightness HJD (HJD-2450000)
Acknowledgements: Daniel Bramich, dbramich(at)eso.org
(End) Daniel Bramich [ESO, Germany], Patricia Vannier [CDS] 31-Jan-2013
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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