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J/A+A/374/504       UBVI photometry of NGC 7654              (Pandey+, 2001)

NGC 7654: An interesting cluster to study star formation history Pandey, A.K., Nilakshi, Ogura, K., Sagar, R., Tarusawa, K. <Astron. Astrophys. 374, 504 (2001)> =2001A&A...374..504P
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, UBVRI Keywords: open cluster; spatial structure, mass function, star formation Abstract: CCD UBVIc photometry in a wide field around the open cluster NGC 7654 has been carried out for ∼17860 stars, down to V∼20. The reddening across the cluster region is found to be variable with E(B-V) from 0.46mag to 0.80mag. The cluster is situated at a distance of 1380±70pc. The colour magnitude diagrams show a large age spread in the ages. Star formation was biased towards relatively higher masses during the early phase of star formation whereas most of the low mass stars of the cluster were formed during the later phase. The star formation seems to have been a gradual process that proceeded sequentially in mass and terminated with the formation of most massive stars. The present data do not support a uniform mass function (MF) for different regions in the cluster. Description: File table2.dat contains the photometric data of the stars in the field of NGC 7654. The stars are numbered in the increasing order of their radial distance from the cluster center. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 23 24 12 +61 35.0 NGC 7654 = M 52 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 114 17862 UBVIc photometric data of the stars in the field of NGC 7654
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 I6 --- No Identification number of the stars 8- 15 F8.2 pix Xpos Pixel coordinate (1) 17- 24 F8.2 pix Ypos Pixel coordinate (1) 28- 33 F6.3 mag Vmag Magnitude in the V (Johnson) band 35- 41 F7.3 mag B-V ? B-V colour index 42 A1 --- n_B-V [*] *: no value 44- 49 F6.3 mag V-I ? V-I (Cousins) colour index 50 A1 --- n_V-I [*] *: no value 52- 57 F6.3 mag U-B ? U-B colour index 58 A1 --- n_U-B [*] *: no value 61- 65 F5.3 mag e_Imag ? Errors in the I (Cousins) band 66 A1 --- n_Imag [*] no value 69- 73 F5.3 mag e_Vmag Errors in the V (Johnson) band 77- 81 F5.3 mag e_Bmag ? Errors in the B (Johnson) band 82 A1 --- n_Bmag [*] *: no value 85- 89 F5.3 mag e_Umag ? Errors in the U (Johnson) band 90 A1 --- n_Umag [*] *: no value 93- 97 F5.3 --- chi chi parameter in the V (Johnson) band (3) 100-105 F6.3 --- Sharp Sharpness parameter in the V (Johnson) band (2) 106-114 F9.3 arcsec r Radial distance of the stars from the cluster center (X=855, Y=755)
Note (1): Pixel coordinates: * Origin: X=0, Y=0 * Orientation East: X=0, West: X=1600; South: Y=0, North: Y=1600 * Scale: 1 pix = 1.5arcsec Note (2): the sharpness parameter measures how well the PSF fits the object. Note (3): the χ parameter measures the average rms deviation to the PSF fit normalized to the expected errors.
Acknowledgements: A.K. Pandey
(End) Patricia Bauer [CDS] 12-Jul-2001
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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