U.S. Naval Observatory Astrometry Department

The Radio Optical Reference Frame
Optical Image Database - CCD Images

Available items include:

Here sn is the source name in IAU convention like 1954-388 and # denotes the observing run the image is from:
  #   Telescope  Observation Date   Image Scale 
  d   KPNO 0.9m  April 94           0.68 "/pixel
  e   KPNO 0.9m  Oct.  94           0.68
  f   CTIO 0.9m  Dec.  94           0.40
  g   CTIO 0.9m  Feb.  95           0.40
  h   KPNO 0.9m  June  95           0.68
  i   CTIO 0.9m  Sept. 95           0.40 
  j   CTIO 4.0m  Oct.,Nov. 95       0.43
  k   KPNO 0.9m  Jan.  96           0.68
  l   CTIO 0.9m  July  96           0.40
  m   CTIO 0.9m  July  97           0.40
All images are 199 by 199 pixels in size with North up and East to the left. Note the different scale for each telescope. The radio source object is in the center at x=y=100. WARNING: there are some empty fields. In such a case the x=y=100 position points to empty background and no optical counterpart is visible within the limiting magnitude. For more details see the related paper: Zacharias et al., "Accurate optical positions of extragalactic radio reference frame sources", AJ 118, Nov 1999. When using the finding charts provided here, please cite that reference.

Last modified: Wed Jun 13 09:34:41 EDT 2001
Send comments on this page to nz@usno.navy.mil