                               
                          Astrometrica 3.0 Demo-Images
                         


  P94J3-1.ST6, P94J3-2.ST6
  

  These two images of comet  P/1994 J3 (Shoemaker 4) = 1994k "P/Shoemaker 4"
  were taken by  Dennis di Cicco  from his backyard observatory at  Sudbury,
  MA, USA (MPC Observatory Code 817). He used a ST-6 CCD camera on a 11 inch 
  Schmidt-Cassegrain telescope at f/6.7.

  Dennis discovered a faint minor planet on these images,  taken on July 12,
  1994. He notes that he found this minor planet,  which has never been seen
  again,  "on a fluke of 'perfect' observing conditions".  In  the meantime,
  Dennis has discoverd a number of other asteroids  while doing routine work
  at his backyard observatory - some as bright as 16th magnitude, and others 
  as faint as 19th magnitude.

  Both the comet (which is faint and diffuse) and the minor planet (which is
  very faint) are difficult to measure.


  P94P1-1.ST6, P94P1-2.ST6
  

  These images  of comet  P/1994 P1 (Machholz 2) = 1994o "P/Machholz 2" were 
  taken on September 8, 1994 at the private observatory Obermair/Meyer  (MPC 
  Observatory Code 540), which is located at  48.4425 N,  14.2753 E,  815m 
  above sea level,  using a ST-6 CCD camera on a 288mm  f/5.2 Schmidt-Casse-
  grain at prime focus.

  Measuring the precise positions of bright comets, where the nuclear region 
  hides in a bright coma, is quite difficult.  Please read the section 'Tips 
  & Suggestions' of "Astrometrica's"  README.TXT  file for some hints on how 
  to proceed. 

  Some 5' northeast of the comet, one (Fragment "B") of four faint,  diffuse
  companions of this comet can be seen on these 30 second  frames.  However,  
  for precise astrometric observations of this compnent,  a  longer exposure 
  time was necessary.


  3145-1.ST6, 3145-2.ST6
  

  These two images were also taken at the private observatory Obermair/Meyer
  with the equipment already described above.  While observing the "Critical
  List"-minor planet (3145) "Walter Adams" we independently discovered minor
  planet 1994 UC on these frames, taken on October 29, 1994. It was found by  
  A. Nakamuka at Kuma Kogen, Japan, only seven hours earlier.

  These images were taken using SBIG's  'Track and Accumulate'  mode.  After  
  loading these images in "Astrometrica", press the Button labeld 'Mid-Ex'in 
  the 'Edit Parameters' Dialog Window  to calculate the time of mid-exposure  
  form the times when the five 30 second snapshots were started:

                                3145-1.ST6       3145-2.ST6

   Snapshot 1:                    20:34:57         21:53:49
   Snapshot 2:                    20:36:18         21:55:14
   Snapshot 3:                    20:37:15         21:56:11
   Snapshot 4:                    20:38:12         21:57:08
   Snapshot 5:                    20:39:09         21:58:05
                                  
   Time of Mid-Exposure:          20:37:25         21:56:20

