Contents.
      planet: 6 - Saturn
  satellites: S12-Helene:22
total number: 22
        type: relative
       dates: 1985-1987
 observatory: 874 - Itajuba (Laboratorio Nacional de Astrofisica)

Reference.
   Veiga C.H., Vieira Martins R. (2000)
   Astrometric photographic observations of Helene.
   Astron. Astrophys. Suppl. Ser. V. 143. P. 405.
   2000A&AS__143__405V

Informations.
         relative to: S6-Titan: 22
     reference frame: astrometric
     centre of frame: topocentre
    epoch of equinox: J2000
          time scale: TT
           reduction: no information
         coordinates: X, Y
    diff. refraction: no information
            receptor: photographic
           telescope: no information
           observers: Veiga C.H., Vieira Martins R.
 data included in standard data file: no

Comments.
            Abstract:
            Astrometric photographic positions of the Saturnian
            satellite Helene obtained from 22 plates taken in 6
            nights are presented. The observations are distributed
            between 5 missions in 1985 and 1987. All positions are
            compared with those calculated by Jacobson (1999,
            personal communication). The residuals have mean and
            standard deviation smaller than 0.25" and 0.30"
            respectively.
          evaluation: The differences  O-C(X), O-C(Y) are published
                      in the article. For these values one have:
                                                     X        Y
                      M. (mean)                    0.178"   -0.101"
                      R.M.S. (root mean square)    0.434"    0.250"
                      The differences  O-C(X)e, O-C(Y)e were also
                      calculated by N.Emelianov with the theory by
                      P. Oberty for Helene and with the theory by
                      Harper & Taylor for Titan.
                      With these O-C one have
                                                     X        Y
                      M. (mean)                   -0.087"   -0.181"
                      R.M.S. (root mean square)    0.470"    0.536"

Format.
 Bytes Format Units   Label     Explanations
-----------------------------------------------------------------
 1-  4  I4    yr      Obs.Y     Year of the mean instant
                                of observation
     6  I1    ---     Obs.M     Month of the mean instant
                                of observation
 8- 15  F8.5  d       Obs.D     Decimal day of the mean instant
                                of observation
17- 24  F8.3  arcsec  X         Differential topocentric
                                coordinate, {Delta}RAcosDE (1)
26- 32  F7.3  arcsec  Y         Differential topocentric
                                coordinate, {Delta}DE (1)
34- 39  F6.3  arcsec  (O-C)X    Observed minus calculated
                                value of X
41- 46  F6.3  arcsec  (O-C)Y    Observed minus calculated
                                value of Y
-----------------------------------------------------------------
Note (1): Differential topocentric coordinates are referred to
          Titan.  The reference system is defined by the mean
          equator and equinox J2000
----------------------------------------------
Obs.Y  Obs.D       X       Y     (O-C)X (O-C)Y
    Obs.M        arcsec  arcsec  arcsec arcsec
----------------------------------------------