J/A+AS/119/221 UBVRI photometry of stars in Berkeley 86 (Deeg+, 1996) ================================================================================ Deep CCD photometry and the initial mass function of the core of the OB cluster Berkeley 86. Deeg H.J., Ninkov Z. =1996A&AS..119..221D (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Clusters, open ; Photometry, CCD Keywords: stars: luminosity function, mass function - open clusters and associations: individual: Bky 86 Description: Based on photometry of deep CCD frames of the central region of the OB cluster Berkeley 86, we derive the cluster mass function. The absence of current star formation, and the cluster's young age of about 6Myrs, leads to the conclusion that the initial mass function (IMF) and the current mass function are identical for stars with m<10m_{sun}_. In the range of 1.2-20m_{sun}_, an IMF with a slope of {GAMMA}=-1.3+/-0.3 is found. This value agrees well with other recent determinations of young clusters IMFs which are close to the classical Salpeter IMF with {GAMMA}=-1.35. Sections of the IMF of Berkeley 86 that are significantly steeper, or flatter, are most likely the result of a dip in the star's mass distribution in the range of 3.5-10m_{sun}_. Similar dips may have led to steep IMFs over narrow mass ranges, as reported in the literature for some other clusters. No sign for a low mass turn-over in the IMF of Berkeley 86 is found for masses extending down to 0.85 m_{sun}_. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1 88 544 UBVRI photometry of 544 stars in Bky86 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1 -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- ID [1,544]+ ID number of stars in this paper 5- 9 A5 --- Forbes-ID ID number of stars in Forbes et al. (1992AJ....103..916F) (1) 11- 18 F8.4 deg RAdeg += Right Ascencion (J2000) (2) 20- 26 F7.4 deg DEdeg Declination (J2000) (2) 28- 32 F5.2 mag Vmag V magnitude 34- 37 F4.2 mag e_Vmag rms uncertainty on Vmag 39- 43 F5.2 mag U-B ? U-B color index 45- 48 F4.2 mag e_U-B ? rms uncertainty on U-B 50- 53 F4.2 mag B-V ? B-V color index 55- 58 F4.2 mag e_B-V ? rms uncertainty on B-V 60- 63 F4.2 mag V-R V-R color index 65- 68 F4.2 mag e_V-R rms uncertainty on V-R 70- 73 F4.2 mag R-I R-I color index 75- 78 F4.2 mag e_R-I rms uncertainty on R-I 80- 83 F4.2 mag E(B-V) E(B-V) extinction 85- 88 F4.2 solMass logM ? log mass of cluster-members; 9.99= non-member; only entries for stars with V<18.5 -------------------------------------------------------------------------------- Note (1): ID 162 = Forbes-ID 1 is also HD228969 Note (2): Precision is about 1 arcsec. -------------------------------------------------------------------------------- Courtesy: Hans-Jorg Deeg References: Forbes, D. et al., 1992, AJ, 103, 916 =1992AJ....103..916F ================================================================================ (End) Patricia Bauer [CDS] 25-Apr-1996