This allows positions for an exact time to be worked out quickly and easily from an
ephemeris. It was originally intended for when orbital elements were not
readily obtainable (e.g. objects still on the NEOCP) so that accurate
telescope pointing and rate of motion could be determined. However, at
Great Shefford it is now used for all ephemeris work at the telescope and
also when reducing measures with Astrometrica, to accurately interpolate between ephemeris intervals
and to save time by sending the speed and position angle information to
Astrometrica and invoking the track & stack command automatically.
A minor planet or comet designation can be typed into the 'Object'
box to retrieve an ephemeris from the Minor Planet Center's MPES
service. Or the Object box can be left blank to retrieve all current
NEOCP objects that meet criteria set by the user. Alternatively, the
Object box drop-down list displays a list of the objects
on the NEOCP and allows an ephemeris for an individual NEOCP object to
be retrieved. Variant orbits from the MPES or NEOCP can also be
Pressing the Calculate button works out the RA, Dec, Speed and
PA of motion using a second order interpolation method for the specified
A separate 'pad' can be undocked from the main form (visible to the
right in the screen shot above) which is set to be an 'always on
top' window for ease of use when transferring values into other software.
Pressing the blue "Astrometrica" button sends the calculated Speed
and PA to Astrometrica and initiates the completion of the Astrometrica
"Stack Images" function.
See the User
Guide for further functionality and more detailed information. Download the software