Content asteroid: 1999 XY143 satellites: companion total number: 1 type: position dates: 2008-2008 observatory: 250 - Hubble Space Telescope Reference. Noll K. S., Grundy W. M., Benecchi S. D., Levison H. A. 1999 XY_143, 1999 RY_214, and 2002 VT_130. IAU Circ., No. 9075, #2 (2009). 2009IAUC.9075....2N Informations. relative to: the primary reference frame: astrometric ICRF centre of frame: topocentric epoch of equinox: J2000 time scale: UTC reduction: no information coordinates: X, Y (R.A., Decl. in the communication) diff. refraction: no information receptor: telescope: Wide Field Planetary Camera 2 Comments. R.A., Decl. in the communication Format. 1. Year of the moment of observation 2. Month of the moment of observation 3. Day of the moment of observation 4. X - relative right ascension, arcsec 5. SigX - the error of X , arcsec 6. Y - relative declination, arcsec 7. SigY - the error of Y, arcsec ------------------------------------------------------- Year Day X Sig X Y Sig Y Month arcsec arcsec arcsec arcsec -------------------------------------------------------