J/MNRAS/430/221 NGC 2849 and NGC 6134 UBVI photometry (Ahumada+, 2013)
NGC 2849 and NGC 6134: two more BOCCE open clusters.
Ahumada A.V., Cignoni M., Bragaglia A., Donati P., Tosi M., Marconi G.
<Mon. Not. R. Astron. Soc., 430, 221-233 (2013)>
=2013MNRAS.430..221A 2013MNRAS.430..221A
ADC_Keywords: Clusters, open ; Photometry, UBVRI ; Photometry, CCD
Keywords: Hertzsprung-Russell and colour-magnitude diagrams -
open clusters and associations: general -
open clusters and associations: individual: NGC 2849 -
open clusters and associations: individual: NGC 6134
Abstract:
We present CCD photometry of two southern open clusters. As part of
the Bologna Open Cluster Chemical Evolution project we obtained BVI
and UBVI imaging for NGC 2849 and NGC 6134, respectively. By means of
the synthetic colour-magnitude diagram method and using various
evolutionary sets of stellar evolution tracks with various
metallicities, we determined at the same time age, distance and
reddening. We also determined an approximate metallicity for NGC 2849,
for which the information is not available from sounder methods like
high-resolution spectroscopy. NGC 2849 turned to be 0.85-1.0Gyr old
with a solar metallicity. The foreground reddening is
E(B-V)=0.28-0.32, and the true distance modulus (m-M)0=13.8-13.9.
For NGC 6134 we did not obtain fully consistent answers from the V,
B-V and V, V-I photometry, an unexpected problem, since both the
metallicity and the reddening are known (from high-resolution
spectroscopy and the U-B, B-V two colours diagram, respectively). This
may either indicate a difficulty of current models (evolutionary
tracks and/or models of atmosphere) to accurately reproduce colours,
or be related to differences in the metal mixture assumed by the
models and those of the clusters. Assuming the spectroscopic abundance
and the colour excess [E(B-V)=0.35] from the U-B, B-V plot, we derived
a best age between 0.82 and 0.95Gyr and a distance modulus 10.5.
Description:
NGC 2849 was observed with the Dutch telescope (La Silla Observatory,
ESO) 10 May 1997. NGC 6134 was observed with DFOSC at the Danish
telescope (La Silla Observatory, ESO) 15/16 May 2001.
For NGC 2849, The filters used were B (ESO#419), V (ESO#420) and I
(ESO#465). For NGC 6134, The observations were taken with the filters
U (ESO#632), B (ESO#450), V (ESO#451) and I (ESO#425).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
ngc2849.dat 107 1157 Optical BVI photometric catalogue for the open
cluster NGC 2849
ngc6134.dat 118 6623 Optical UBVI photometric catalogue for the open
cluster NGC 6134
--------------------------------------------------------------------------------
See also:
J/A+AS/140/135 : NGC 3680 & NGC 6134 Stromgren photometry (Bruntt+, 1999)
J/A+A/385/867 : 5 open clusters CCD Δa-photometry (Paunzen+, 2002)
J/other/RMxAA/39.39 : CCD Photometry of NGC 2658, 2849, 3247 (Ahumada, 2003)
Byte-by-byte Description of file: ngc2849.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 5 I4 --- Id Star identification number (1)
8- 14 F7.3 pix Xpos X pixel coordinate
17- 23 F7.3 pix Ypos Y pixel coordinate
26 I1 h RAh Right ascension (J2000) (hour)
28- 29 I2 min RAm Right ascension (J2000) (minutes)
31- 36 F6.3 s RAs Right ascension (J2000) (seconds)
38 A1 --- DE- Declination (J2000) (sign)
39- 40 I2 deg DEd Declination (J2000) (degrees)
42- 43 I2 arcmin DEm Declination (J2000) (minutes)
45- 50 F6.3 arcsec DEs Declination (J2000) (seconds)
52- 57 F6.3 mag Bmag ?=99.999 B band magnitude
60- 64 F5.3 mag e_Bmag ?=9.990 B band magnitude error
66- 71 F6.3 mag Vmagb ?=99.999 V band magnitude determined from (B-V)
74- 78 F5.3 mag e_Vmagb ?=9.990 V band magnitude error from (B-V)
80- 85 F6.3 mag Vmagi ?=99.999 V band magnitude determined from (V-I)
88- 92 F5.3 mag e_Vmagi ?=9.990 V band magnitude error from (V-I)
95-100 F6.3 mag Imag ?=99.999 I band magnitude
103-107 F5.3 mag e_Imag ?=9.990 I band magnitude error
--------------------------------------------------------------------------------
Note (1): ID numbers < 1000 are for the central field,
ID > 1000 for the "external" field.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: ngc6134.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 5 I4 --- Id Star identification number
7- 13 F7.2 pix Xpos X pixel coordinate
15- 21 F7.2 pix Ypos Y pixel coordinate
23- 24 I2 h RAh Right ascension (J2000) (hour)
26- 27 I2 min RAm Right ascension (J2000) (minutes)
29- 34 F6.3 s RAs Right ascension (J2000) (seconds)
36 A1 --- DE- Declination (J2000) (sign)
37- 38 I2 deg DEd Declination (J2000) (degrees)
40- 41 I2 arcmin DEm Declination (J2000) (minutes)
43- 48 F6.3 arcsec DEs Declination (J2000) (seconds)
50- 55 F6.3 mag Umag ?=99.999 U band magnitude
58- 62 F5.3 mag e_Umag ?=9.990 U band magnitude error
64- 69 F6.3 mag Bmag ?=99.999 B band magnitude
72- 76 F5.3 mag e_Bmag ?=9.990 B band magnitude error
78- 83 F6.3 mag Vmagb ?=99.999 V band magnitude determined from (B-V)
86- 90 F5.3 mag e_Vmagb ?=9.990 V band magnitude error from (B-V)
92- 97 F6.3 mag Vmagi ?=99.999 V band magnitude determined from (V-I)
100-104 F5.3 mag e_Vmagi ?=9.990 V band magnitude error from (V-I)
106-111 F6.3 mag Imag ?=99.999 I band magnitude
114-118 F5.3 mag e_Imag ?=9.990 I band magnitude error
--------------------------------------------------------------------------------
Acknowledgements:
Andrea Ahumada, andreav.ahumada(at)gmail.com
(End) Patricia Vannier [CDS] 25-Oct-2013