J/ApJ/608/243 CCD BVI photometry of M12 stars (Hargis+, 2004)
The luminosity function and color-magnitude diagram of the globular cluster M12.
Hargis J.R., Sandquist E.L., Bolte M.
<Astrophys. J., 608, 243-260 (2004)>
=2004ApJ...608..243H 2004ApJ...608..243H
ADC_Keywords: Clusters, globular ; Photometry, CCD ; Photometry, UBVRI
Keywords: diffusion - globular clusters: individual (M12) - stars: evolution -
stars: luminosity function, mass function
Description:
The observations were done on the nights of UT dates 1995 May 6 and 9
by using the Kitt Peak National Observatory (KPNO) 0.9 m telescope.
The file contains BVI data of the globular cluster M12. All frames
were taken using a 2048x2048 pixel CCD with pixels covering
0.68 arcseconds on a side, for a total field of approximately
23.2 arcminutes on a side.
The data were calibrated against Stetson (2000PASP..112..925S 2000PASP..112..925S)
standard stars.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
16 47 14.5 -01 56 52 M 12 = NGC 6218 = C 1644-018
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
photom.dat 86 17301 BVI Photometry for M12 stars
--------------------------------------------------------------------------------
Byte-by-byte Description of file: photom.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Seq Sequential number
7- 14 F8.3 pix Xpos X coordinate in pixels (1)
16- 23 F8.3 pix Ypos Y coordinate in pixels (1)
26- 32 F7.4 mag Bmag ?=0.0 Johnson B magnitude
35- 41 F7.4 mag e_Bmag ?=0.0 Johnson B magnitude error
44- 50 F7.4 mag Vmag ?=0.0 Johnson V magnitude
53- 59 F7.4 mag e_Vmag ?=0.0 Johnson V magnitude error
62- 68 F7.4 mag Icmag ?=0.0 Cousins I magnitude
71- 77 F7.4 mag e_Icmag ?=0.0 Cousins I magnitude error
80- 86 F7.4 --- Chi Reduced chi2
--------------------------------------------------------------------------------
Note (1): 1 pix = 0.68"
--------------------------------------------------------------------------------
Acknowledgements: Eric Sandquist <erics'sciences.sdsu.edu>
History:
* 19-Aug-2004: the file with the photometric results has been replaced
by a new one, since the original file contained uncalibrated
instrumental magnitudes. Only stars having measurements in at least 2
filter bands could be properly calibrated, so the number of stars has
been reduced from 20704 to 17301.
(End) Eric Sandquist [San Diego State Univ.], Patricia Vannier [CDS] 29-Jun-2004