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J/AJ/110/1186                          SX Phe stars in NGC 5053 (Nemec+ 1995)

SX Phoenecis stars in the extremely metal-poor globular cluster NGC 5053 Nemec J.M., Mateo M., Burke M., Olszewski E.W. <Astron. J. 110, 1186 (1995)> =1995AJ....110.1186N
ADC_Keywords: Clusters, globular ; Stars, blue ; Stars, variable ; Photometry, CCD Abstract: The results of a major search for photometrically variable blue straggler stars (BSs) in the extremely metal-poor globular cluster NGC 5053 are presented. The survey is based on photometry of over 200 CCD frames (BVI passbands) taken on 18 nights between 1985 and 1994. Five of the 16 BSs monitored for variability are identified as SX Phe stars and their photometric characteristics derived. These five stars are among the shortest-period (49<P<57min), lowest luminosity (3.0≲M_V≲3.3mag), smallest amplitude (0.08≲A_V≲0.25mag) SX Phe stars presently known. Their colors and locations in both B and V period-luminosity (P-L) diagrams suggest that four of the stars (blue stragglers 11, 13, 14, and 15 in the Nemec & Cohen 1989 catalog (1989ApJ...336..780N) are fundamental-mode pulsators, while the fifth and bluest star, No. 7, appears to be a first-overtone pulsator. One of the stars, No. 11, exhibits cycle-to-cycle light variations that are consistent with multimode pulsations; however, not enough photometric information is available to derive its secondary pulsation period. Masses for the stars, estimated directly from the general equation of stellar pulsation and relative to the RR Lyrae stars, range from 0.53M (NC7) to 1.8M (NC13). The SX Phe stars are used to derive improved P-L-[Fe/H] relations for SX Phe stars, from which a revised distance modulus of (m-M)0=16.06 is obtained for NGC 5053. Objects: -------------------------------------------- RA (2000) DE Designation(s) -------------------------------------------- 13 16 26.9 +17 41 52 NGC 5053 = C 1313+179 -------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 69 69 Photometry of the SKJ standard stars table4.dat 52 26 Mean B,V photometry of the blue stragglers table5.dat 35 25 Summary of the blue straggler monitoring table6.dat 43 72 Photometry of blue straggler 10 in NGC 5053 table7.dat 43 33 Photometry of blue straggler 12 in NGC 5053 table8.dat 43 31 Photometry of blue straggler 19 in NGC 5053 table9.dat 43 35 Photometry of blue straggler 21 in NGC 5053 table10.dat 43 21 Photometry of blue straggler 23 in NGC 5053 table11.dat 43 74 Photometry of blue straggler 25 in NGC 5053 table12.dat 43 49 *Photometry of blue straggler 7 in NGC 5053 table13.dat 43 42 Photometry of blue straggler 11 in NGC 5053 table14.dat 43 209 Photometry of blue straggler 13 in NGC 5053 table15.dat 43 41 Photometry of blue straggler 14 in NGC 5053 table16.dat 43 35 Photometry of blue straggler 15 in NGC 5053 table17.dat 74 29 *Properties of the five SX Phe stars in NGC 5053 table18.dat 43 18 Derived log (P)-m0 (M15) relations tables.tex 164 1707 TeX version of all tables
Note on table12.dat: All the B magnitudes from N17 were calculated from I magnitudes through a V-I,B-V transformation. Note on table17.dat: The following general assumptions were made: Mbol(Sun)=+4.76; [Fe/H]=2.41dex for every star in NGC 5053; E(B-V)=0.06, A_V=3.1xE(B-V)=0.19, A_B=4.1xE(B-V)=0.25; Note that the periods given by NNL for the SX Phe stars were preliminary estimates and differ slightly from those reported here.
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 3 A3 --- Star Star name from Sandage et al. (1977AJ.....82..389S) 6- 8 A3 --- Type Type of star (1) 10- 15 F6.2 mag BmagSKJ SKJ B magnitude (2) 17- 22 F6.2 mag Bmag Mean B magnitude derived by authors 24- 27 F4.2 mag e_Bmag Std dev in B for all nights 29- 30 I2 --- o_Bmag Number of B frames star measured on 32 I1 --- n_Bmag Number of nights B measurements made 34- 39 F6.2 mag VmagSKJ SKJ V magnitude 41- 46 F6.2 mag Vmag Mean V magnitude derived by authors 48- 51 F4.2 mag e_Vmag Std dev in V for all nights 53- 55 I3 --- o_Vmag Number of V frames star measured on 57 I1 --- n_Vmag Number of nights V measurements made 59- 63 F5.2 mag B-V(SKJ) SKJ B-V color 65- 69 F5.2 mag B-V Mean B-V color
Note (1): Type: rgb = red giant branch; bhb = blue horizontal branch; rhb = red horizontal branch; agb = asymptotic giant branch. Note (2): SKJ = Sandage, Katem & Johnson (1977AJ.....82..389S)
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Star Star number from Nemec and Cohen catalog (1989ApJ...336..780N) 3 A1 --- f_Star [v] Indicates photometric variability 5- 10 F6.2 mag Vmag Derived mean V magnitude 12- 15 F4.2 mag e_Vmag Std dev in V magnitude 17- 19 I3 --- o_Vmag Number of V frames star measured on 21- 22 I2 --- n_Vmag Number of nights V measurements made 24- 29 F6.2 mag Bmag Derived mean B magnitude 31- 34 F4.2 mag e_Bmag Std dev in Bmag 36- 38 I3 --- o_Bmag Number of B frames star measured on 40- 41 I2 --- n_Bmag Number of nights B measurements made 43- 47 F5.2 mag B-V B-V color 49- 52 F4.2 mag e_B-V B-V error
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Star Star number 4- 9 F6.2 mag Vmag Derived mean V magnitude 11- 15 F5.2 mag B-V B-V color 16 A1 --- u_B-V B-V uncertainty flag 19- 27 A9 --- Behave Photometric behavior, e.g. "constant" 30- 35 A6 --- Confid Confidence rating, e.g. "high"
Byte-by-byte Description of file: table[6-9].dat table1[0-6].dat
Bytes Format Units Label Explanations
1- 2 I2 --- Night Night number 4- 13 F10.4 d HJD-2440000 HJD (epoch 2440000) of observation 15- 21 F7.3 mag Vmag ? V magnitude 23- 28 F6.3 mag e_Vmag ? V magnitude error 30- 36 F7.3 mag Bmag ? B magnitude 38- 43 F6.3 mag e_Bmag ? B error
Byte-by-byte Description of file: table17.dat
Bytes Format Units Label Explanations
1- 22 A22 --- Property Property of SX Phe star 25- 34 A10 --- NC7 Value of property for NC7 35- 44 A10 --- NC11 Value of property for NC11 45- 54 A10 --- NC13 Value of property for NC13 55- 64 A10 --- NC14 Value of property for NC14 65- 74 A10 --- NC15 Value of property for NC15
Byte-by-byte Description of file: table18.dat
Bytes Format Units Label Explanations
1 A1 --- Band [BVK] Passband (1) 4- 16 A13 --- Type Type of variable star 19 A1 --- Mode [FH] Pulsation mode (2) 21- 24 I4 --- Num Number of stars 26- 31 F6.2 --- Int Intercept 33- 38 F6.2 --- Slope []? Slope 40- 43 F4.2 --- e_Slope []? Slope standard error
Note (1): B Passband: r2 = 99.71, RMS-error=0.14 (r: regression coefficient) V Passband: r2 = 99.67, RMS-error=0.14 K Passband: r2 = 99.75, RMS-error=0.07 Note (2): F = Fundamental; H = First overtone
Table1: Telescopes and CCD cameras ------------------------------------------------------------------ Night Tel Obs Focal CCD Frame Pixel Scale Grain RON (1) (2) (3) (4) (5) ----------------------------------------------------------------- 1-3 CFH HC f/4.0 RCA1 320512 30 0.41 28.6 75. 4-5 P60 NS f/8.7 RCA3 320512 30 1.29 6.0 30. 6-7 CFH NR f/4.0 RCA2 6401024 15 0.20 11.6 51. 8 P60 N f/4.3 RCA3 320512 30 0.47 6.0 30. 9-11 P60 S f/8.7 RCA3 320512 30 1.29 6.0 30. 12 P60 M f/4.3 TI4 800800 15 0.47 2.0 9. 13-15 S90 MO f/9 TI2 800800 15 0.15 2.6 7.3 16 P60 M f/4.3 TI4 800800 15 0.47 2.0 9. 17 P60 M f/4.3 Tek 10241024 24 0.38 2.4 5.5 18 DAO N f/5 SITe-1 10241024 25 0.55 4.7 13. Notes: (1) See Table 2 for the dates that correspond to these night numbers. (2) CFH - Canada-France-Hawaii 3.6m P60 - Palomar 1.5m (60 in.) S90 - Steward Observatory 2.3m (90 in.) DAO - Dominion Astrophysical Observatory 1.8m (72 in.) (3) C = Christian C., H = Heasley J., M = Mateo M., N = Nemec J., O = Olszewski E., R = Richer H., S = Schombert J. (4) See Boroson, Thompson & Shectman (1983, AJ, 88, 1707) for a discussion of the P60, f/8.7 re-imaging optics. (5) On Night 12 the raw data were binned 2x2 at the telescope. On Night 16 the raw data were binned 2x2 using post-processing software Table2: Summary of CCD observations -------------------------------------------------------------------------------- Night Date HJD Num Blue straggler RR Lyr (1) (2) (3) (4) (5) -------------------------------------------------------------------------------- 1 1985 Feb 19/20 6117.13-.17 2B, 1V 1-3,13,17,24,25 4 2 1985 Feb 20/21 6118.12-.16 3B, 3V 1-3,13,17,24,25 4 3 1985 Feb 21/22 6119.09-.14 6B, 5V 1-3,13,17,24,25 4 4 1986 Jun 5/6 6587.80-.86 3B, 3V 12,14-16,20,21 1,2,7 5 1986 Jun 6/7 6588.76-.82 3B, 3V 12,14-16,20,21 1,2,7 6 1987 Apr 28/29 6914.99-.02 5V 1-4,7,13,22,23,25,26 8,10 7 1987 Apr 29/30 6915.81-.90 4B, 6V 10,14,21,25 2 8 1987 May 22/23 6938.68-.88 14V 1-11,13,25 10 9 1987 Jun 23/24 6970.68-.82 3B, 3V 1,2,4-7,11,17,19,22,23,24 3-6,8,10 3B, 3V 2,3,6,8-16,18,21,24,25 1,2,4,7 10 1987 Jun 24/25 6971.68-.79 2B, 2V 1,2,4,5,7,17,19,22,23 3-6,8,10 2B, 2V 2,3,6,8-16,18,21,24,25 1,2,4,7 11 1987 Jun 25/26 6972.69-.76 3B, 2V 1,2,4,5,7,17,19,22,23 3-6,8,10 2B, 2V 2,3,6,8-16,18,21,24,25 1,2,4,7 12 1988 Feb 15/16 7207.93-.07 1B,31V 1-4,7,10,13,17,24,25,26 4,10 13 1988 Feb 26/27 7218.79-.05 46V 1-4,13 none 14 1988 Feb 27/28 7219.79-.02 58V 1-4,13 none 15 1988 Feb 28/29 7220.78-.83 11V 1-4,13 none 16 1988 Mar 8/9 7229.79-.83 8V 1-5,10,13,17,25 10 17 1991 Jun 8/9 8416.67-.80 1I,15V 1-7,10-15,17,19,21-26 3,4,6-8,10 18 1994 Apr 9/10 9452.74-.03 23B,29V none 1-4,6-10 Notes: (1) On Nights 9-11, CCD frames were taken of the East and West sides of the cluster, with some overlap; these are summarized on the upper and lower rows, respectively. (2) Range in HJD (epoch 2440000) of CCD frame (3) Number of B and V frames (nnB, nnV) (4) List of blue stragglers monitored (5) List of RR Lyrae monitored References: Nemec & Cohen 1989 catalog, 1989ApJ...336..780N Origin: AAS CD-ROM series, Volume 5, 1995 Lee Brotzman [ADS] 30-Oct-1995
(End) [CDS] 10-Jan-1996
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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