J/A+A/436/527       UBVIc photometry of NGC 4852              (Carraro+, 2005)

Luminosity and mass functions of galactic open clusters: II. NGC 4852. Carraro G., Baume G., Piotto G., Mendez R.A., Schrnidtobreik L. <Astron. Astrophys. 436, 527 (2005)> =2005A&A...436..527C 2005A&A...436..527C
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, CCD ; Photometry, Cousins Keywords: open clusters and associations: individual: NGC 4852 - Hertzsprung-Russell (HR) and C-M diagrams Abstract: We present wide-field deep UBVIc photometry for the previously unstudied open cluster NGC 4852 down to a limiting magnitude Ic∼24, obtained from observations taken with the Wide Field Imager camera on-board the MPG/ESO 2.2m telescope at La Silla (ESO, Chile), in the photometric night of July 7, 2002. These data are used to obtain the first estimate of the cluster basic parameters, to study the cluster spatial extension by means of star counts, and to derive the Luminosity (LF) and Mass Functions (MF). The cluster radius turns out to be 5.0±1.0arcmin. The cluster emerges clearly from the field down to V=20mag. At fainter magnitudes, it is completely confused with the general Galactic disk field. The stars inside this region define a young open cluster (200 million years old) 1.1kpc far from the Sun (m-M=11.60, E(B-V)=0.45). The Present Day Mass Functions (PDMF) from the V photometry is one of the most extended in mass obtained to date, and can be represented as a power-law with a slope alpha=2.3±0.3 and (the Salpeter MF in this notation has a slope alpha=2.35), in the mass range 3.2≤m/m≤0.6. Below this mass, the MF cannot be considered as representative of the cluster MF, as the cluster merges with the field and therefore the MF is the result of the combined effect of strong irregularities in the stellar background and interaction of the cluster with the dense Galactic field. The cluster total mass at the limiting magnitude results to be 2570±210M. Objects: -------------------------------------------------------- RA (2000) DE GLON GLAT Designation(s) -------------------------------------------------------- 13 00 06.0 -59 36 02 304.03 +3.25 NGC 4852 -------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table5.dat 112 145926 Photometry of NGC 4852 -------------------------------------------------------------------------------- See also: J/A+A/404/927 : UBVRI photometry of NGC 2422 (Prisinzano+, 2003) Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 I6 --- Seq Sequential number 9- 16 F8.5 h RAhr Right ascension (J2000) (1) 19- 27 F9.5 deg DEdeg Declination (J2000) (1) 30- 38 F9.3 pix Xpos CCD position along X axis 41- 49 F9.3 pix Ypos CCD position along Y axis 51- 56 F6.3 mag Vmag Johnson V band magnitude 60- 64 F5.3 mag e_Vmag Error in V band magnitude 66- 72 F7.3 mag B-V ?=99.999 Johnson (B-V) color index 75- 80 F6.3 mag e_B-V ?=99.999 Error in B-V color 83- 88 F6.3 mag U-B ?=99.999 Johnson (U-B) color index 91- 96 F6.3 mag e_U-B ?=99.999 Error in U-B color 99-104 F6.3 mag V-Ic Johnson-Cousins (V-I) color index 108-112 F5.3 mag e_V-Ic Error in V-Ic color -------------------------------------------------------------------------------- Note (1): The center is in 13.0025, -59.6133. The scale is 0.238"/pix. -------------------------------------------------------------------------------- Acknowledgements: Giovanni Carraro, gcarraro(at)das.uchile.cl History: * 21-Mar-2005: First version * 19-Jun-2005: More accurate right ascension (the original had only 3 decimals figures). References: Prisinzano et al., Paper I (NGC 4815) 2001A&A...369..851P 2001A&A...369..851P
(End) Patricia Vannier [CDS] 21-Mar-2005
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