CDROM/AJ/V105/P1441 IC 4665 (Prosser 1993) ================================================================================ The Open Cluster IC 4665 Charles F. Prosser <1993, AJ, 105, 1441> =1993AJ....105.1441P ================================================================================ Abstract: The results of a combined astrometric, photometric, and spectroscopic program to identify members of the open cluster IC 4665 are presented. Numerous new proper motion/photometric candidate members and at least 23 M dwarfs with H-alpha emission have been identified. A reanalysis of IC 4665's age using different methods yields conflicting results ranging from approx. 3x10^7 yr to the age of the Pleiades. This study provides a list of candidate cluster members in the intermediate and low-mass regime of this cluster. Future spectroscopic observations of these candidates should eventually identify true cluster members. The results of new echelle observations of some candidates and the photometric monitoring of one apparent cluster member are given in an appendix. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1.dat 120 55 IC 4665: 30 s proper motion candidates table2.dat 120 142 IC 4665: Yerkes and Lick proper motion candidates -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- P Running identification number, P 4- 5 2X --- --- Blank 6-10 F5.2 mag V Johnson V magnitude 11-15 F5.2 mag B-V []? B-V color 16-20 F5.2 mag V-I []? V-I color 21-25 F5.2 mag R-I []? R-I color 26 1X --- --- Blank 27-28 I2 --- n_V Number of observations at V magnitude 29-30 I2 --- n_B Number of observations at B magnitude 31-32 I2 --- n_I Number of observations at I magnitude 33-34 I2 --- n_R Number of observations at R magnitude 35 1X --- --- Blank 36-38 F3.0 h RAh Right ascension 1950 39-41 F3.0 min RAm R.A. 42-47 F6.2 s RAs R.A. 48 A1 --- DE- Sign of declination, always blank 49-50 F2.0 deg DEd Declination 1950 51-53 F3.0 arcmin DEm Dec. 54-58 F5.1 arcsec DEs Dec. 59 1X --- --- Blank 60-66 F7.2 mm X Survey coordinates, X 67-73 F7.2 mm Y Survey coordinates, Y 74-80 F7.2 0.01arcsec/yr mu_x Relative proper motion component, mu_x 81-87 F7.2 0.01arcsec/yr mu_y Relative proper motion component, mu_y 88-93 F6.2 0.01arcsec/yr e_mu_x Error in mu_x, sigma_x 94-99 F6.2 0.01arcsec/yr e_my_y Error in mu_y, sigma_y 100-101 2X --- --- Blank 102-105 A4 --- Prob *Proper motion membership probability 106-108 6X --- --- Blank 112-113 A2 --- Phot Membership on the basis of photometry 114-115 2X --- --- Blank 116-120 A5 --- Other Other previous identifications -------------------------------------------------------------------------------- Notes for file: table1.dat -------------------------------------------------------------------------------- Prob: A proper motion membership probability has been determined from gaussian fitting to the cluster and field proper motion distributions - however the reader is advised not to attach great weight to the probabilities calculated due to the high contamination of field stars found for this cluster. -------------------------------------------------------------------------------- Comments for file: table2.dat -------------------------------------------------------------------------------- Table 2 lists the proper motion candidates recovered from analysis of the Lick 36-inch and Yerkes 40-inch plates. The format of Table 2 is the same as for Table 1, with the addition of a column which gives the number, 'N', of Yerkes plate fields (see printed paper) which contributed a proper motion estimate for the star. Relative proper motions from analysis of more than one Yerkes field were averaged together. No proper motion membership probabilities were calculated for the Lick candidates in Table 2 due to the rough approximations made to correct for magnitude dependent effects in the proper motions during the analysis of the Lick 30min/1hr plate reductions. The first 27 entries in Table 2 are those stars for which proper motions had also been derived from the Lick short exposure plates (Table 1). These 27 entries are separated by a blank line from those remaining Yerkes/Lick proper motion candidates which were not measured on the short exposure plates. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- P Running identification number, P 4- 5 2X --- --- Blank 6-10 F5.2 mag V Johnson V magnitude 11-15 F5.2 mag B-V []? B-V color 16-20 F5.2 mag V-I []? V-I color 21-25 F5.2 mag R-I []? R-I color 26 1X --- --- Blank 27-28 I2 --- n_V Number of observations at V magnitude 29-30 I2 --- n_B Number of observations at B magnitude 31-32 I2 --- n_I Number of observations at I magnitude 33-34 I2 --- n_R Number of observations at R magnitude 35 1X --- --- Blank 36-38 F3.0 h RAh Right ascension 1950 39-41 F3.0 min RAm R.A. 42-47 F6.2 s RAs R.A. 48 A1 --- DE- Sign of declination, always blank 49-50 F2.0 deg DEd Declination 1950 51-53 F3.0 arcmin DEm Dec. 54-58 F5.1 arcsec DEs Dec. 59 1X --- --- Blank 60-66 F7.2 mm X Survey coordinates, X 67-73 F7.2 mm Y Survey coordinates, Y 74-80 F7.2 0.01arcsec/yr mu_x Relative proper motion component, mu_x 81-87 F7.2 0.01arcsec/yr mu_y Relative proper motion component, mu_y 88-93 F6.2 0.01arcsec/yr e_mu_x Error in mu_x, sigma_x 94-99 F6.2 0.01arcsec/yr e_my_y Error in mu_y, sigma_y 100-101 2X --- --- Blank 102-105 A4 --- Prob *Proper motion membership probability 106-108 3X --- --- Blank 109 I1 --- N Num. of Yerkes fields to determine mu 110-111 2X --- --- Blank 112-113 A2 --- Phot Membership on the basis of photometry 114-115 2X --- --- Blank 116-120 A5 --- Other Other previous identifications -------------------------------------------------------------------------------- Notes for file: table2.dat -------------------------------------------------------------------------------- Prob: A proper motion membership probability has been determined from gaussian fitting to the cluster and field proper motion distributions - however the reader is advised not to attach great weight to the probabilities calculated due to the high contamination of field stars found for this cluster. -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 28-Feb-1995