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J/A+A/509/A104      UBVRIJHK photometry of Dolidze 25        (Delgado+, 2010)

Analysis of the stellar population in the central area of the HII region Sh 2-284. Delgado A.J., Djupvik A.A., Alfaro E.J. <Astron. Astrophys. 509, A104 (2010)> =2010A&A...509A.104D
ADC_Keywords: Clusters, open ; Stars, pre-main sequence ; Photometry, UBVRI ; Photometry, infrared Keywords: open clusters and associations: individual: Dolidze 25 - stars: pre-main sequence Abstract: The analysis of our deep UBVRIJHK photometry of Dolidze 25, located in the central area of the HII region Sh 2-284, reveals a young cluster with coeval MS and PMS populations of age 3.2-5Myr. The mass function for the optical PMS population in the mass range above 1.3-3.5M is well fitted by a Salpeter mass function. On the other hand, the NIR photometry results indicate a large number of sources with H-Ks excess, practically distinct from the optical PMS candidate members. In addition, a distinctly older cluster member population of age 40Myr is suggested. The distance determined for the cluster from quantitative fits to ZAMS and isochrones (3.6kpc) is distinctly lower than previously published values. This result originates in the consistent use of low metallicity models for ZAMS fitting, applying published metallicity values for the cluster Description: Photometric color for 1673 stars in the direction of the young open cluster Dolidze 25. UBVRI CCD photometry, calibrated with previously published photoelectric values for some stars in the field, and the observations of standard fields. JHKs photometry, calibrated with matching to 2MASS data. The determination of cluster distance, reddening and age is carried out through comparison with ZAMS, post-MS and PMS isochrones. The reference lines used are obtained from theoretical post-MS and PMS isochrones from the Geneva and Yale groups, for metallicity Z=0.004, in agreement with the spectroscopic metallicity determination published for several cluster members. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 156 1673 Photometric results and membership
See also: II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/A+A/503/107 : Spitzer/IRAC view of Sh2-284 (Puga+, 2009) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 I4 --- Seq Identification number (this work) 7- 9 I3 --- WEBDA Identification number in WEBDA 11- 26 A16 --- 2MASS Identification in 2MASS (HHMMSSss+DDMMSSs) 31- 40 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 43- 50 F8.6 deg DEdeg Declination in decimal degrees (J2000) 52- 56 F5.2 mag U-B ?=99.99 U-B colour index (1) 58- 62 F5.2 mag e_U-B ?=99.99 Error in U-B (1) 64- 68 F5.2 mag B-V ?=99.99 B-V colour index (1) 70- 74 F5.2 mag e_B-V ?=99.99 Error in B-V (1) 76- 80 F5.2 mag Vmag ?=99.99 V magnitude (1) 82- 86 F5.2 mag e_Vmag ?=99.99 Error in Vmag (1) 88- 92 F5.2 mag V-Rc ?=99.99 V-Rc colour index (1) 94- 98 F5.2 mag e_V-Rc ?=99.99 Error in V-Rc (1) 100-104 F5.2 mag V-Ic ?=99.99 V-Ic colour index (1) 106-110 F5.2 mag e_V-Ic ?=99.99 Error in V-Ic (1) 112-116 F5.2 mag Jmag ?=99.99 J magnitude (1) 118-122 F5.2 mag e_Jmag ?=99.99 Error in Jmag (1) 124-128 F5.2 mag Hmag ?=99.99 H magnitude (1) 130-134 F5.2 mag e_Hmag ?=99.99 Error in Hmag (1) 136-140 F5.2 mag Kmag ?=99.99 K magnitude (1) 142-146 F5.2 mag e_Kmag ?=99.99 Error in Kmag (1) 151 I1 --- Mm ?=- Membership assignment (2) 156 I1 --- IRex ?=- NIR excess status (3)
Note (1): A 99.99 entry indicates a non-detection. Note (2): Membership assignment is numbered as follows: 1 = young MS and post-MS member 2 = old MS and post-MS member 3 = PMS member according to 3 CM diagrams 4 = PMS member according to 4 CM diagrams Note (3): NIR excess as follows: 0 = no IR excess from J-H/H-Ks diagram 1 = probable IR excess source 2 = bona-fide IR excess source
Acknowledgements: Delgado A.J., delgado(at)iaa.es
(End) A.J. Delgado. [IAA.CSIC], Patricia Vannier [CDS] 16-Nov-2009
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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