J/A+A/361/929 IC 4651 uvby photometry (Meibom, 2000) ================================================================================ New Color-magnitude Diagram for the Open Cluster IC 4651. Deep Stroemgren uvby CCD photometry in a large field. Meibom S. =2000A&A...361..929M ================================================================================ ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, uvby Keywords: Galaxy: open clusters and associations: individual: IC 4651 - stars: Hertzsprung-Russel (HR) and C-M diagrams Description: New accurate CCD photometry in the u, v, b and y bands of the Stroemgren system filters has been obtained for 17640 stars to approximately. V=20mag in a approximately 21' x 21' field centered on the intermediate-age open cluster IC 4651. The observations was obtained with the Danish 1.5-m telescope at the European Southern Observatory, La Silla, Chile. Table 1 contains information about the Date, Night, Filter, Exposure time, Airmass, CCD rotation angle, and RA- , DE-offsets for all 89 frames. Table 2 gives cross-references between the MEI-system (this paper) and the Lindoff (1972A&AS....7..231L, IC 4651 NNN), Eggen (1971ApJ...166...87E, Cl* IC 4651 Egg NN), Anthony-Twarog & Twarog (1987AJ.....94.1222A, Cl* IC 4651 AT 1-NNN, Cl* IC 4651 AT 2-NN), and Anthony-Twarog et al. (1988AJ.....95.1453A, Cl* IC 4651 AMC I-NNN, Cl* IC 4651 AMC NNNN) identification numbers. Table 3 is the final catalogue of the new Stroemgren uvby photometry, ordered by MEI identification number. For each star, it gives the MEI number, Global CCD x- and y-coordinates, J2000 coordinates , the new y, b, v, and u magnitudes on the standard system, number of detections of the individual stars, and their mean errors. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 42 89 Observation log for IC 4651 table2.dat 27 506 Cross-references between the new numbering system, Meibom 2000 (prefix MEI), and previous identification numbers of the stars in IC 4651 table3.dat 128 17640 ubvy photometry table1.tex 145 148 LaTeX version of table1 table2.tex 123 811 LaTeX version of table2 -------------------------------------------------------------------------------- See also: J/A+A/299/53 : Red giants in NGC 3680 and IC 4651 (Mermilliod+, 1995) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 8 A8 --- Frame Frame identification 10- 17 A8 "DD/MM/YY" Date Observation date 19- 20 A2 --- Night Night number 22 A1 ---- Filter [ubvy] Filter 24- 26 I3 s ExpTime Exposure time 28- 32 F5.3 --- Airmass Airmass 34- 36 I3 deg Rot CCD rotation angle 38- 39 I2 arcmin oRA {alpha} offset 41- 42 I2 arcmin oDE {delta} offset -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 I5 --- MEI Meibom number (this paper) 7- 9 I3 --- IC4651 ? Lindoff (1972A&AS....7..231L) number (1) 11- 13 I3 --- Eggen ? Eggen (1971ApJ...166...87E) number (1) 15- 18 I4 --- AT ? Anthony-Twarog & Twarog (1987AJ.....94.1222A) number (1) 20- 22 I3 --- AMCI ? Twarog et al. (1988AJ.....95.1453A) number from CCD photometry (1) 24- 27 I4 --- AMC ? Twarog et al. (1988AJ.....95.1453A) number from photographic photometry (1) -------------------------------------------------------------------------------- Note (1): The identifications in Simbad are: Lindoff (1972A&AS....7..231L) : IC 4651 NNN Eggen (1971ApJ...166...87E) : Cl* IC 4651 Egg NN Anthony-Twarog & Twarog (1987AJ.....94.1222A) : Cl* IC 4651 AT 1-NNN for numbers as 1NNN and Cl* IC 4651 AT 2-NN for numbers as 20NN Twarog et al. (1988AJ.....95.1453A): CCD: Cl* IC 4651 AMC I-NNN photographic: Cl* IC 4651 AMC NNNN -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 5 I5 --- MEI New stellar ID (prefix MEI) 6 A1 --- f_MEI [*] indicates correspondances in table2. 7 I1 --- Flag [0/7] Code indicating type of star (1) 9- 17 F9.3 pix Xpos Global CCD x-coordinate (total field) 19- 27 F9.3 pix Ypos Global CCD y-coordinate (total field) 29- 30 I2 h RAh Right Ascension J2000 (hour) 32- 33 I2 min RAm Right Ascension J2000 (minutes) 35- 39 F5.2 s RAs Right Ascension J2000 (seconds) 41 A1 --- DE- Declination sign (J2000) 42- 43 I2 deg DEd Declination J2000 (degrees) 45- 46 I2 arcmin DEm Declination J2000 (arcminutes) 48- 52 F5.2 arcsec DEs Declination J2000 (arcseconds) 54- 60 F7.4 mag ymag Stroemgren y magnitude of star on standard system 62- 63 I2 --- o_ymag Number of detections in the y filter 65- 70 F6.4 mag e_ymag Standard error of the weighted mean y magnitude 73- 79 F7.4 mag bmag Stroemgren b magnitude of star on standard system 81- 82 I2 --- o_bmag Number of detections in the b filter 84- 89 F6.4 mag e_bmag Standard error of the weighted mean b magnitude 91- 97 F7.4 mag vmag Stroemgren v magnitude of star on standard system 99-100 I2 --- o_vmag Number of detections in the v filter 102-107 F6.4 mag e_vmag Standard error of the weighted mean v magnitude 109-115 F7.4 mag umag Stroemgren u magnitude of star on standard system 117-118 I2 --- o_umag Number of detections in the u filter 120-125 F6.4 mag e_umag Standard error of the weighted mean u magnitude -------------------------------------------------------------------------------- Note (1): The analysis of membership and duplicity leading to the 8 categories (0-7) of the stars in IC 4651, is based on the present data and additional radial-velocity information, and will be the subject of a forthcoming paper. Flag-codes: 0 : Field stars 1 : Single red giant members (9 stars) 2 : Single main-sequence members (29) 3 : Binary red giant members (9) 4 : Binary main-sequence members (34) 5 : Field stars determined from color-magnitude diagram analysis (17) 6 : "new" (discovered) main-sequence stars (654) 7 : "new" (discovered) red giant star candidates (2) -------------------------------------------------------------------------------- History: Lindoff numbers of table2.dat corrected on 16-May-2002 Acknowledgements: S. Meibom ================================================================================ (End) Patricia Bauer [CDS] 11-Aug-2000