J/AJ/116/1775 BV photometry of M53 (Rey+, 1998)
CCD photometry of the globular cluster M 53.
I. Color-magnitude data and blue straggler stars.
Rey S.-C., Lee Y.-W., Byun Y.-I., Chun M.-S.
<Astron. J. 116, 1775 (1998)>
=1998AJ....116.1775R 1998AJ....116.1775R
ADC_Keywords: Clusters, globular ; Stars, blue ; Photometry, CCD
Keywords: blue stragglers - color-magnitude diagrams -
globular clusters: individual: M 53
Abstract:
The first large-format CCD color-magnitude diagram (CMD) in the B and
V passbands is presented for the Galactic globular cluster M53
(NGC 5024). The observations consist of 40 pairs of B and V CCD frames
with FWHM<1.2" in a pattern covering a 12'x13' region of M53. These
frames were used to produce color-magnitude data for more than 20,000
stars from the tip of the red giant branch (RGB) to about 2 mag below
the main-sequence turnoff (V∼22). The CMD reveals a classic example of
a metal-poor stellar system, with the horizontal branch (HB)
predominantly blueward of the RR Lyrae instability strip and the
relatively steep RGB. The blue HB of M53 does not show the blue tail
phenomenon that is observed in M15. The relative age dating based on
the color difference between the turnoff and the base of RGB reveals
no significant age difference (Δt<1Gyr) between M53 and M92. We
have discovered 114 new blue straggler stars (BSSs) in the field of
M53. The analysis of bright (V<19.39) BSSs clearly shows a bimodal
radial distribution with a high frequency in the inner and outer
regions but a distinct dip in the intermediate region. The
distribution is similar to that found in M3, a globular cluster with a
similar central density and concentration.
Objects:
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RA (2000) DE Designation(s)
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13 12 55.2 +18 12 09 NGC 5024 = M 53
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 35 23535 CCD photometry for M 53
table3.dat 88 54 Identified RR Lyrae variables
table4.dat 88 16 New RR Lyrae candidates
table7.dat 38 117 M 53 blue straggler stars
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See also:
V/97 : Updated 3rd Cat Variable Stars in Globular Clusters (Clement+ 1997)
Byte-by-byte Description of file: table2.dat table7.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- RLB/BSS Sequential number (1)
7- 14 F8.2 pix xpos X coordinate (2)
16- 23 F8.2 pix ypos Y coordinate (2)
25- 29 F5.2 mag Vmag V magnitude
31- 35 F5.2 mag B-V B-V colour index
37- 38 I2 --- HC91 ? Heasley & Christian (1991AJ....101..967H 1991AJ....101..967H)
number
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Note (1): For table2.dat: Cl* NGC 5024 RLB NNNNN in Simbad
For table7.dat: Cl* NGC 5024 BSS NNN in Simbad
Note (2): Positions relative to the cluster center. 1 pix = 0.22"
North is down and east is to the right.
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Byte-by-byte Description of file: table3.dat table4.dat
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Bytes Format Units Label Explanations
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1 A1 --- Region Region designation (1)
3- 5 A3 --- Name Name (2)
7- 9 I3 --- RLB RLB number
11 A1 --- Band [BV] Band
13- 18 F6.3 mag mag1 ? Magnitude in Band at JD=2449807.872
20- 25 F6.3 mag mag2 ? Magnitude in Band at JD=2449807.895
27- 32 F6.3 mag mag3 Magnitude in Band at JD=2449807.939
34- 39 F6.3 mag mag4 Magnitude in Band at JD=2449807.965
41- 46 F6.3 mag mag5 Magnitude in Band at JD=2449808.796
48- 53 F6.3 mag mag6 Magnitude in Band at JD=2449808.881
55- 60 F6.3 mag mag7 Magnitude in Band at JD=2449808.932
62- 67 F6.3 mag mag8 Magnitude in Band at JD=2449809.007
69- 74 F6.3 mag mag9 Magnitude in Band at JD=2449809.046
76- 81 F6.3 mag mag10 ? Magnitude in Band at JD=2449809.065
83- 88 F6.3 mag mag11 ? Magnitude in Band at JD=2449809.113
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Note (1): A: NE region
B: NW Region
C: SE Region
D: SW Region
Note (2): SNN : Sawyer Hogg, 1973, Cat. V/97 designation,
(Cl* NGC 5024 SAW VNNN in Simbad, table3.dat)
VN: this paper designation (Cl* NGC 5024 RLB VN in Simbad, table4.dat)
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History: From AJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 08-Dec-1998