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J/A+AS/111/85             Open cluster Pis 20                   (Vazquez+, 1995)
A detailed study of the open cluster Pismis 20
      VAZQUEZ R.A., WILL J.-M., PRADO P., FEINSTEIN A.
      <Astron. Astrophys. Suppl. Ser. 111, 85 (1995)>
      =1995A&AS..111...85V      (SIMBAD/NED Reference)
ADC_Keywords:  Clusters, open; Photometry, CCD

Keywords: open cluster: Pis 20 - stars: mass function - stars: WR -
          stars: individual: WR 67; Wolf-Rayet

Description:
   The very young open cluster Pis 20 has been investigated using CCD UBVR
   photometry. New blue faint members were found down to V=19mag. With them
   we obtain a better definition of the lower cluster main sequence. Using
   the fitting method, we derive a cluster distance of d=3600pc
   (V0-MV=12.80). The mean color excess is <EB-V≥1.24mag.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table2            48      196   Observed colors and magnitudes in Pismis 20
table5            63      127   Intrinsic colors, magnitudes and masses of
                                  Pismis 20 stars


Byte-by-byte Description of file: table2

   Bytes Format  Units   Label    Explanations

   2-  4  I3     ---     SeqNum   Sequential star number
   6- 11  F6.2   ---     X        X position
  13- 18  F6.2   ---     Y        Y position
  20- 24  F5.2   mag     Vmag     V magnitude
  25- 26  A2     ---     u_Vmag   [: ] Uncertainty flag on Vmag (1)
  28- 31  F4.2   mag     B-V      B-V colour index
  32- 33  A2     ---     u_B-V    [: ] Uncertainty flag on B-V (1)
  35- 39  F5.2   mag     U-B      []? U-B colour index
  40- 41  A2     ---     u_U-B    [: ] Uncertainty flag on U-B (1)
  43- 46  F4.2   mag     V-R      []? V-R colour index
  47- 48  A2     ---     u_V-R    [: ] Uncertainty flag on V-R (1)

Note (1): ' :' indicates stars with error from 0.07 to 0.10 mag
          '::' indicates stars with errors larger than 0.10 mag


Byte-by-byte Description of file: table5

   Bytes Format  Units   Label    Explanations

   2-  4  I3     ---     SeqNum   Sequential star number
   6- 10  F5.2   mag     V0       Intrinsic V magnitude
  15- 19  F5.2   mag     (B-V)0   []? Intrinsic B-V colour index
  23- 26  F4.2   mag     E(B-V)   []? B-V colour excess
  31- 35  F5.2   mag     (U-B)0   []? Intrinsic U-B colour index
  39- 42  F4.2   mag     E(U-B)   []? U-B colour excess
  44- 48  F5.2   mag     MV       Absolute V magnitude
  54- 59  F6.3   solMass Mass     Star mass
      63  A1     ---     Rem      [ab*] Remarks (1)

Note (1): (a) indicates that color excesses were computed through a relation
               between spectral types and color indices following
               Schmidt-Kaler (1982 in: Landolt-Bornstein, Neue Serie VI/2b)
          (b) V0 was obtained adopting a mean cluster reddening
               <EB-V ≥ 1.24. The mass corresponds to the most
               massive cluster star
          (*) denotes possible members

(End)                                           Patricia Bauer [CDS] 16-Jan-1995