J/AJ/127/1000 Stromgren and Ca photometry of NGC 3680 (Anthony-Twarog+, 2004)
uvbyCaHβ CCD photometry of clusters.
IV. Solving the riddle of NGC 3680.
Anthony-Twarog B.J., Twarog B.A.
<Astron. J., 127, 1000-1013 (2004)>
=2004AJ....127.1000A 2004AJ....127.1000A
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, uvby
Keywords: open clusters and associations: individual (NGC 3680) -
stars: evolution - techniques: photometric
Abstract:
CCD photometry on the intermediate-band uvbyCaHβ system is
presented for the open cluster, NGC 3680. Restricting the data to
probable cluster members using the color-magnitude diagram (CMD) and
the photometric indices alone defines a sample of 34 stars at
the cluster turnoff that imply E(b-y)=0.042±0.002(s.e.m.) or
E(B-V)=0.058±0.003(s.e.m.), where the errors refer to internal
errors alone. With this reddening, [Fe/H] is derived from both m1
and hk using both b-y and Hβ as the temperature indices.
Description:
The Caby system was initially defined and developed using traditional
photoelectric photometry obtained at a number of observatories, but
predominantly Cerro Tololo Inter-American Observatory (CTIO) and Kitt
Peak National Observatory, between 1983 and 1996.
Included in this sample were eight stars in the field of NGC 3680,
observed with a pulse-counting system equipped with an S-20
photomultiplier on the 1.0 and 1.5m telescopes at CTIO between
1989 and 1992.
Objects:
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RA (2000) DE Designation(s)
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11 25 42 -43 15.0 NGC 3680 = Cl Melotte 106
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 119 466 uvbyCaHβ photometry in NGC 3680
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See also:
J/AJ/119/2282 : Stromgren photometry of IC 4651 (Anthony-Twarog+, 2000)
J/AJ/125/1383 : Stromgren photometry of NGC 6253 (Anthony-Twarog+, 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Seq WEBDA primary identification number (1)
7- 12 F6.2 pix Xpos WEBDA X pixel coordinate
14- 19 F6.2 pix Ypos WEBDA Y pixel coordinate
21- 26 F6.3 mag Vmag The V-band magnitude
28- 32 F5.3 mag b-y The Stroemgren (b-y) color
34- 39 F6.3 mag m1 ? The Stroemgren m1 index magnitude
41 A1 --- n_m1 [g] calibration of m1 (2)
43- 48 F6.3 mag c1 ? The Stroemgren C1 index magnitude
50 A1 --- n_c1 [g] calibration of c1 (2)
52- 56 F5.3 mag beta ? The Hβ index magnitude
58- 62 F5.3 mag hk ? The hk index [(Ca-b) - (b-y)]
64- 68 F5.3 mag e_Vmag Standard error of the mean in Vmag
70- 74 F5.3 mag e_b-y Standard error of the mean in b-y
76- 80 F5.3 mag e_m1 ? Standard error of the mean in m1
82- 86 F5.3 mag e_c1 ? Standard error of the mean in c1
88- 92 F5.3 mag e_beta ? Standard error of the mean in beta
94- 98 F5.3 mag e_hk ? Standard error of the mean in hk
100-101 I2 --- Ny Number of y-band frames
103-104 I2 --- Nb Number of b-band frames
106-107 I2 --- Nv Number of v-band frames
109-110 I2 --- Nu Number of u-band frames
112-113 I2 --- Nw Number of w-band frames
115-116 I2 --- Nn Number of n-band frames
118-119 I2 --- NCa Number of Ca-band frames
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Note (1): Number as in the WEDBA database, at
http://obswww.unige.ch/webda/cgi-bin/cross.cgi?ngc3680
Note (2): g indicates index was transformed using the giant calibration.
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History:
From electronic version of the journal
References:
Anthony-Twarog & Twarog, Paper I 2000AJ....119.2282A 2000AJ....119.2282A, Cat. J/AJ/119/2282
Anthony-Twarog & Twarog, Paper II 2000AJ....120.3111A 2000AJ....120.3111A
Twarog et al., Paper III 2003AJ....125.1383T 2003AJ....125.1383T, Cat. J/AJ/125/1383
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 02-Jul-2004