J/MNRAS/349/641     VIc, CT1 magnitudes in Trumpler 5        (Piatti+, 2004)

The old open cluster Trumpler 5: a reddened, metal-poor anticentre cluster. Piatti A.E., Claria J.J., Ahumada A.V. <Mon. Not. R. Astron. Soc., 349, 641-648 (2004)> =2004MNRAS.349..641P 2004MNRAS.349..641P
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, VRI ; Photometry, CMT1T2V Keywords: techniques: photometric - open clusters and associations: general - open clusters and associations: individual: Trumpler 5 Abstract: CCD observations in the Johnson V, Kron-Cousins I and the Washington system C and T1 passbands have been used to generate colour-magnitude diagrams (CMDs) reaching down to V∼21.0mag and T1∼19.0 for Trumpler 5, an old open cluster located towards the Galactic anticentre. Our data analysis confirms the existence of non-uniform extinction over the face of the cluster, the mean E(V-I) and E(C-T1) values being 0.80±0.05 and 1.17±0.15, respectively. Through comparison of the cluster CMDs with theoretical isochrones of the Geneva group, Washington Standard Giant Branches and measures of V and T1 indices, we derive the following values for the cluster apparent distance modulus, age, and metallicity: V-MV=13.80±0.30 (corresponding to a distance from the Sun of 2.4±0.5 kpc and 0.04kpc above the Galactic plane), t=5.0±0.5Gyr and [Fe/H]=-0.30±0.15. We estimate the cluster angular radius to be about 7.7 arcmin (=5.4pc) from star counts carried out within and outside the cluster field. Description: The observations were carried out with the Cerro Tololo Inter-American Observatory (CTIO) 0.9-m telescope in 1997 December, with the 2048x2048pix CCD Tektronix 2K #3, as described in Paper I (Piatti et al., Cat. J/MNRAS/340/1249) for the open cluster NGC 2194. The scale on the chip is 0.40arcsec/pixel, yielding an area of 13.6x13.6arcmin2. The filters used were the Johnson V, Kron-Cousins I and Washington system C and T1. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 06 36 42 +09 26.0 Cl Trumpler 5 ---------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 52 5094 CCD VI data of stars in the field of Tr 5 table2.dat 52 2953 CDD T1C data of stars in the field of Tr 5 -------------------------------------------------------------------------------- See also: J/A+AS/133/25 : CCD BVI photometry of Trumpler 5 (Kaluzny 1998) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- PCA Sequential number, Cl* Trumpler 5 PCA NNNN 6- 13 F8.3 pix Xpos X position (G1) 15- 22 F8.3 pix Ypos Y position (G1) 25- 30 F6.3 mag Vmag V magnitude 32- 36 F5.3 mag e_Vmag rms uncertainty on Vmag 38- 43 F6.3 mag V-Ic V-Ic colour index 45- 49 F5.3 mag e_V-Ic rms uncertainty on V-Ic 52 I1 --- o_Vmag Number of observations -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- PCA Sequential number, Cl* Trumpler 5 PCA NNNN 6- 13 F8.3 pix Xpos X position (G1) 15- 22 F8.3 pix Ypos Y position (G1) 25- 30 F6.3 mag T1mag T1 magnitude 32- 36 F5.3 mag e_T1mag rms uncertainty on T1mag 38- 43 F6.3 mag C-T1 C-T1 colour index 45- 49 F5.3 mag e_C-T1 rms uncertainty on C-T1 52 I1 --- o_T1mag Number of observations -------------------------------------------------------------------------------- Global notes: Note (G1): North is up and east is to the left. 1 pix = 0.40" The adopted position of the cluster centre is (Xc, Yc) = (990±25, 1400±25) pixels. -------------------------------------------------------------------------------- Acknowledgements: Andres Piatti
(End) James Marcout, Patricia Vannier [CDS] 07-May-2004
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