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J/AJ/112/1061         BV photometry of NGC 7099 (Bergbusch 1996)

Luminosity functions for post-turnoff stars in globular clusters. II. NGC 7099 Bergbusch P.A. <Astron. J. 112, 1061 (1996)> =1996AJ....112.1061B
ADC_Keywords: Clusters, globular ; Stars, bright ; Photometry, CCD Abstract: New BV CCD photometry for the bright stars in cluster fields centered on the core of NGC 7099 is presented. The morphology of the LF though the turnoff region is similar to that found in other metal-poor clusters in that the relative number of turnoff to giant stars is lower than predicted by canonical models. Comparisons with evolutionary sequences of horizontal branch stars suggest a reddening E(B-V)=0.06 and a distance modulus (m-M)_V=14.83. Isochrone fits to [Fe/H]=-2.03, [O/Fe]=+0.70 models are consistent with an age of at least 14 Gyr. The model LF for this age accurately predicts the brightness of the tip of the red giant branch (RGB) as well as the location of the break which signals the transition from the base of the RGB to the main sequence. There is an indication that the evolutionary pause on the RGB, which manifests itself as a bump in the LF, occurs one magnitude fainter than the models predict. The excess of HB stars with respect to giants is confirmed and implies a helium abundance Y=0.28, which is higher than that found in other metal-poor globular clusters from the R method. From a comparison with the metal-rich, blue horizontal branch cluster NGC 288, it is argued that age cannot by itself be the solution to the second parameter problem. Objects: ------------------------------------------ RA (2000) DE Designation(s) ------------------------------------------ 21 40.3 -23 11 NGC 7099 ------------------------------------------ File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table6.dat 51 852 Photometry for stars brighter than V=18.0
Byte-by-byte Description of file: table6.dat
Bytes Format Units Label Explanations
1- 6 I6 --- Star Star number 8- 15 F8.2 pix Xpos X pixel coordinate 17- 24 F8.2 pix Ypos Y pixel coordinate 28- 33 F6.3 mag Vmag V magnitude 37- 42 F6.3 mag B-V B-V color index 47- 51 F5.3 --- Chi Mean profile fitting statistic, chi
Origin: AAS CD-ROM series, Volume 7, 1996 Lee Brotzman [ADS] 25-Sep-1996
(End) [CDS] 30-Jan-1997
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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