Contents.

            asteroid: (136199)Eris  
          satellites: Dysnomia   
        total number: 2
                type: position
               dates: 2015
         observatory: 250 - Hubble Space Telescope  

Reference.
Brown, Michael E.; Butler, Bryan J.
Medium-sized Satellites of Large Kuiper Belt Objects
The Astronomical Journal. Vol. 156 (4). Id 164 (2018)
2018AJ....156..164B

Informations.
         relative to: the primary
     reference frame: astrometric ICRF
     centre of frame: topocentric
    epoch of equinox: J2000
          time scale: UTC
           reduction: no information
         coordinates: Delta(RA), Delta(Dec) 
    diff. refraction: 
            receptor: 
           telescope: WF3

Comments.
 
Format
  1. JD - Julian date of moment of observation with decimals 
  2. Delta(RA) - relative right ascension, mas
  3. eRA - error in Delta(RA), mas
  4. Delta(Dec) - relative declination, mas
  5. eDec - error in Delta(Dec), mas

-----------------------------------------
  JD        Delta(RA) eRA Delta(Dec) eDec
              mas     mas    mas     mas
-----------------------------------------