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J/MNRAS/337/133    UBV(RI)c photometry in clusters Tr 1 and Be 11 (Yadav+, 2002)
A deep UBVRI CCD photometric study of the open clusters Tr 1 and Be 11.
    Yadav R.K.S., Sagar R.
   <Mon. Not. R. Astron. Soc. 337, 133 (2002)>
   =2002MNRAS.337..133Y
ADC_Keywords: Clusters, open ; Photometry, CCD ; Photometry, UBVRI

Keywords: Hertzsprung-Russell (HR) diagram -
          stars: luminosity function, mass function  -
          open cluster and associations: individual: Tr 1 -
          open cluster and associations: individual: Be 11 -
          galaxies: stars clusters

Abstract:
    We present deep UBV(RI)C charge-coupled device (CCD) photometry for
    the young open star clusters Tr 1 and Be 11. The CCD data for Be 11
    are obtained for the first time. The sample consists of ∼1500 stars
    reaching down to V∼21mag. Analysis of the radial distribution of the
    stellar surface density indicates that radius values for Tr 1 and
    Be 11 are 2.3 and 1.5pc, respectively. The interstellar extinction
    across the face of the imaged clusters region seems to be non-uniform
    with a mean value of E(B-V)=0.60±0.05 and 0.95±0.05mag for Tr 1
    and Be 11, respectively. A random positional variation of E(B-V) is
    present in both the clusters. In the cluster Be 11, the reason for the
    random positional variation may be the apparent association of the
    H II region (S 213). The 2MASS JHK data in combination with the optical
    data in the cluster Be 11 yield E(J-K)=0.40±0.20mag and
    E(V-K)=2.20±0.20mag. Colour excess diagrams indicate a normal
    interstellar extinction law in the direction of the cluster Be 11.

Description:
    The UBV Johnson and RI Cousins observations were obtained, using a
    2KxK CCD system at the f/13 Cassegrain focus of the Sampurnanand
    104-cm telescope of the State Observatory, Nainital during 2000
    November. Each pixel of a 2048x2048 CCD corresponds to a square
    of size 0.36" on the sky.
Objects:
    ----------------------------------------------------------
       RA  (2000)  DE       Designation(s)
    ----------------------------------------------------------
    01 35 40    +61 17 20   Trumpler 1 cluster = C 0132+610
    01 35 40    +61 02 20   Trumpler 1 field
    04 20 36    +44 55 58   Berkeley 11 cluster = C 0417+448
    04 20 34    +44 40 08   Berkeley 11 field
    ----------------------------------------------------------

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
tr1.dat           57     1289  *Trumpler 1 cluster (in table4 or paper)
tr1f.dat          57      892   Trumpler 1 field region (in table4 or paper)
be11.dat          57      587   Berkeley 11 cluster (in table5 of paper)
be11f.dat         57      298   Bekeley 11 field region (in table5 of paper)

Note on tr1.dat: electronic table4 of paper looks corrupted (March 2006),
     see the "History" section below


Byte-by-byte Description of file: *.dat

   Bytes Format Units   Label   Explanations

       1  A1    ---     n_Seq   [F] 'F' for field (F) star (files *f.dat)
   2-  5  I4    ---     Seq     Sequential number of the star (1)
   7- 12  F6.2  pix     Xpos    X position (2)
  14- 19  F6.2  pix     Ypos    Y position (2)
  21- 26  F6.3  mag     Vmag    Johnson V magnitude
  28- 33  F6.3  mag     U-B     ? Johnson U-B colour index
  35- 40  F6.3  mag     B-V     ? Johnson B-V colour index
  42- 47  F6.3  mag     V-Rc    ? Johnson-Cousins V-Rc colour index
  49- 54  F6.3  mag     V-Ic    ? Johnson-Cousins V-Ic colour index
  56- 57  A2    ---     Mem     [m nm] Photometric membership
                                (table4a.dat and table5a.dat only)

Note (1): Star designations in Simbad:
     -- For Trumpler 1 : Cl* Trumpler 1 PJ NNNN
        - In the cluster, No 1 to 539 are from Phelps & Janes
          (1994ApJS...90...31P); stars not observed earlier have
          a number starting with 1001.
        - In the field region (table tr1f.dat), stars are numbered
          in the increasing order of X value, numbers 1 to 892.
     -- For Berkeley 11 : Cl* Berkeley 11 YS NNN
        In the cluster and the field region, the stars are numbered
        in increasing order of X value.
Note (2): East is up and north is left. 1pix=0.72arcsec
          Finding charts are in Fig.1 of the paper.


History:
  * 07-Jan-2003: from electronic version of the journal
  * 25-Mar-2006: electronic table for Tr 1 inconsistent;
           tables tr1 and be11 copied from WEBDA archive data
           (http://www.univie.ac.at/webda/archive_anon.html/)
           and reformatted.
(End)                         James Marcout, Patricia Bauer [CDS]    25-Mar-2006