ADC/CDS Standard Document for Catalog:
/journal_tables/AJ/100/1811/

1. Use the ADC Data Viewer Suite to visualize the data.
2. Get the data files via anonymous FTP. (See Note.)

J/AJ/100/1811                 UBV photometry in Ruprecht 106    (Buonanno+ 1990)
================================================================================
Ruprecht 106: a young metal-poor galactic globular cluster.
         Buonanno R., Buscema G., Fusi Pecci F., Richer H.B., Fahlman G.G.
         <Astron. J. 100, 1811 (1990)>
         =1990AJ....100.1811B
================================================================================
ADC_Keywords: Clusters, globular; Photometry, CCD; Photometry, UBV;
              Positional data

Abstract:
    UBV CCD photometry for about 2500 stars in the Galactic globular
    cluster Ruprecht 106 has been performed yielding the first
    color-magnitude diagram (CMD) for this object. The CMD extends
    down to about 2 mag fainter than the main-sequence turnoff (TO).
    The cluster possesses a remarkably flat horizontal branch which
    lies completely to the red of the instability strip. From the
    analysis of the CMD the following basic parameters have been
    determined: [Fe/H] = -1.09 and primordial helium abundance
    Yp = 0.20 0.05. A sizable, highly centrally concentrated population
    of blue stragglers has also been detected. The location and
    morphology of the mean ridge lines in the CMD of Ruprecht 106 have
    then been differentially compared with that of the metal-rich
    cluster 47 Tuc, NGC 362, a cluster of intermediate metallicity,
    and with two well-studied metal-poor clusters, M68 and NGC 6397.
    Significant differences in the positions of the TOs are apparent
    in the comparison with the metal-poor clusters. These differences
    can be explained if Ruprecht 106 is 4-5 Gyr younger than NGC 6397
    and M68, although alternative, less straightforward explanations
    cannot be ruled out. The horizontal branch morphology fits
    perfectly into this picture using models with non-solar-scaled
    abundances ([O/Fe]>0.5), showing that two second parameters are at
    work in this cluster, i.e., age (the dominant) and O enhancement.
    If these findings are confirmed, Ruprecht 106 will turn out to
    be the first young metal-poor Galactic globular cluster discovered,
    with quite strong implications for the study of the collapse and
    enrichment of the Galactic halo.

Notes:
    Field1 is centered on the cluster center (12 35 53 -50 52.6 1950).
    Field2 is located 2.7arcmin east of Field1,

File Summary:
--------------------------------------------------------------------------------
 FileName    Lrecl    Records    Explanations
--------------------------------------------------------------------------------
ReadMe          80          .    This file
table2          31       2262    Field1 (cluster center)
table3          31        296    Field2 (2.7arcmin east)
--------------------------------------------------------------------------------

Byte-by-byte Description of file: table2
--------------------------------------------------------------------------------
   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1-  4  I4     ---     N1       [1/2262]+ Number in Field1
                                    (in Simbad: Cl* Ruprecht 106 BBF 1-N1)
   7- 11  F5.2   mag     Vmag     magnitude
  13- 17  F5.2   mag     B-V      color index
  19- 24  F6.1   arcsec  X        position toward N
  26- 31  F6.1   arcsec  Y        position toward W
--------------------------------------------------------------------------------

Byte-by-byte Description of file: table3
--------------------------------------------------------------------------------
   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1-  4  I4     ---     N2       [1/296]+ Number in Field2
                                    (in Simbad: Cl* Ruprecht 106 BBF 2-N2)
   7- 11  F5.2   mag     Vmag     magnitude
  13- 17  F5.2   mag     B-V      color index
  19- 24  F6.1   arcsec  X        position toward N
  26- 31  F6.1   arcsec  Y        position toward W
--------------------------------------------------------------------------------

History: Keypunched at CDS
================================================================================
(End)                  M.J. Wagner,      Francois Ochsenbein [CDS]   15-Apr-1994