J/ApJ/483/826 BVI CCD photometry of Berkeley 17 (Phelps 1997)
Berkeley 17: the oldest open cluster?
Phelps R.L.
<Astrophys. J. 483, 826 (1997)>
=1997ApJ...483..826P 1997ApJ...483..826P
ADC_Keywords: Clusters, open ; Photometry, CCD
Keywords: Hertzsprung-Russell diagram -
open clusters and associations: individual (Berkeley 17) -
stars: abundances - stars: evolution
Abstract:
Faint magnitude BVI CCD photometry of the central region of the old
open cluster Berkeley 17 (Be 17) has been undertaken to investigate
the claim that it is the oldest open cluster yet discovered (Phelps,
Janes, & Montgomery, 1994AJ....107.1079P 1994AJ....107.1079P). This study reveals Be 17 to
have a metallicity -0.30≤[Fe/H]≤0.00; a reddening 0.52≤E(B-V)≤0.68
or 0.61≤E(V-I)≤0.71; a distance modulus, (m-M)0=12.15±0.10,
corresponding to a distance of 2.7±0.1kpc; a diameter of ∼10pc; a
minimum mass of 400 Msun; and an age of 10-13Gyr. With an adopted age
of 12(+1)(-2)Gyr, these results suggest that Be 17 is indeed the
oldest open cluster yet discovered. The inferred old age for Be 17
indicates that the cluster is an important one for studies of the
differences between open and globular clusters, the transition from
the halo/thick disk to the thin disk of the Galaxy, and even for
establishing the minimum age of the universe.
Objects:
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RA (2000) DE Designation(s)
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05 20.6 +30 36 Cl Berkeley 17 = C 0517+305
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1a.dat 51 619 V, B-V color-magnitude diagram data for Be 17
fig1b.dat 51 797 V, V-I color-magnitude diagram data for Be 17
fig2.dat 51 448 V, V-I color magnitude diagram data for the
Be 17 off-cluster control field
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Byte-by-byte Description of file: fig1a.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Identification number
6- 12 F7.2 pix Xpos X coordinate (1)
15- 21 F7.2 pix Ypos Y coordinate (1)
24- 29 F6.3 mag Vmag V magnitude
32- 37 F6.3 mag B-V B-V color
40- 44 F5.3 mag e_Vmag Error in Vmag
47- 51 F5.3 mag e_B-V Error in B-V
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Note (1): 1 pix = 0.30".
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Byte-by-byte Description of file: fig1b.dat fig2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID Identification number
6- 12 F7.2 pix Xpos X coordinate (1)
15- 21 F7.2 pix Ypos Y coordinate (1)
24- 29 F6.3 mag Vmag V magnitude
32- 37 F6.3 mag V-I V-I color
40- 44 F5.3 mag e_Vmag Error in Vmag
47- 51 F5.3 mag e_V-I Error in V-I
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Note (1): 1 pix = 0.30".
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Origin: AAS CD-ROM series, Volume 9, 1997 Lee E. Brotzman [ADS] 24-Jul-97
(End) [CDS] 05-Feb-1998