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J/A+A/383/296       Saturnian Satellites positions (1996-2000)     (Peng+, 2002)

Positional measuring procedure and CCD observations for Saturnian satellites. Peng Q., Vienne A., Shen K.X. <Astron. Astrophys. 383, 296 (2002)> =2002A&A...383..296P
ADC_Keywords: Solar system ; Planets ; Positional data Keywords: planets and satellites: individual: Saturn - techniques: image processing - astrometry Description: 199 frames of CCD images of the major satellites of Saturn (Mimas, Enceladus, Tethys, Dione, Rhea, Titan, Hyperion and Iapetus), obtained on 1-meter telescope at the Yunnan Observatory during the years of 1996-2000, are measured. These positions are compared to the ones computed with the Vienne & Duriez ephemerides (TASS1.7). The calibrated parameters of the CCD scale and orientation are determined by the comparison of their measurement coordinates with computed positions of four bright satellites of Tethy, Dione, Rhea and Titan. A catalog of 913 differential positions has been obtained. Analysis of the data as inter-satellite positions shows that these observations of the above mentioned four satellites have root-mean-square residuals of 0.04 arcsec in the sense of (O-C) (Observed minus Computed). The positional measuring procedure is proved to be good enough to obtain a small dispersion in the observations for the major Saturn satellites. The format of the present catalog are very near to the one of (Strugnell & Taylor, 1990A&AS...83..289S). The coordinates are corrected by all astrometric effects. So, these positions are really astrometric ones in that meaning that, no astrometric consideration is necessary to use them, even if one wants to touch up the calibration. Nevertheless, the raw pixels are also given in order to allow anyone to reduce again the frames. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table7.dat 123 1311 The catalog
See also: J/A+AS/121/65 : 1990-1994 Saturn's satellites astrometry (Harper+ 1997) J/A+AS/136/257 : Saturn's satellites in 1995/97 (Harper+ 1999) J/A+AS/139/305 : Position of Saturn's satellites (1982-1988) (Veiga+, 1999) Byte-by-byte Description of file: table7.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Opp *Opposition number 5- 8 I4 yr Obs.Y *The year for observations 10- 11 I2 "month" Obs.M *Month for observations 13- 22 F10.7 d Obs.D *UTC date of observations 24- 29 F6.3 s TT-UTC TT-UTC difference 31- 33 A3 --- Obs [286] Observatory code from Minor Planet Center 35- 37 A3 --- Ref [302] Reference code of the catalog (here 302) 39 I1 --- ObsType *[0/1] Observation type 42- 43 A2 --- Obj *Subject satellite, reference satellite 45- 46 A2 --- Note *[0/1] The flag of presence of both coordinates 49- 60 F12.7 arcsec ObsRA The observed coordinates in Right Ascension 63- 74 F12.7 arcsec ObsDE The observed coordinates in Declination 76 I1 --- RefSys *[0/2] The reference system 78 I1 --- Frame [1] The reference frame. Here, 1=geocentric 80- 86 F7.3 arcsec O-CRA ?=999.999 Residuals of observations in Right Asension 88- 94 F7.3 arcsec O-CDE ?=999.999 Residuals of observations in Declination 97 I1 --- Rsat Reference satellite when o-c is computed 100 I1 --- --- [0] Index reserved 103 I1 --- NSer *The number of the series 105-113 F9.3 pix Xpos *?=99999.999 Original coordinate in X direction 115-123 F9.3 pix Ypos *?=99999.999 Original coordinate in Y direction
Note on Opp: Oppsition number. 119 for 1996 to 123 for 2000 Note on Obs.Y, Obs.M, Obs.D: The date is not light time corrected for the UTC Note on ObsType: 0 = alpha, delta 1 = Delta(alpha)cos(delta), Delta(delta) Note on Obj: 0 for Saturn, 1 to 8 for S1 to S8 * when there is no reference satellite that is for observation type 0, C for the center of the plate which is not a physical object Note on Note: 0 = observation absent 1 = observation present Note on RefSys: 0 = mean equator and equinox B1950 1 = true equator and equinox of date of observation 2 = mean equator and equinox J2000 Note on NSer: 1,2,3 and 4 is for 1996, 1997, 1999 and 2000 series respectively. The scale and orientation are the same for all the observations of one series Note on Xpos, Ypos: Difference in raw pixel coordinate between subject satellite and reference satellite in X- anf Y-direction
Acknowledgements: Peng Qingyu
(End) Peng Qingyu [Univ. Jinan], Patricia Bauer [CDS] 27-Sep-2001
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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