Graphics of Asteroid occultation observations.
March 2008.

These plots of the occultation observations have a filename
convention concatenating the asteroid number, asteroid name 
or provisional designation, and occultation date.
The heading for each plot gives the following information:

Line 1
 Object identification, event date, ellipse size and orientation, and
 associated uncertainties.

Line 2
 The offset of the shadow from the center of the earth, and associated
 uncertainty values.

Line 3 [Only when a double star is involved.]
 The separation and Position angle of the components of the double star,
 with associated uncertainty.

Important. In all lines, an uncertainty value is only given if there has been
a meaningful calculation of the particular quantity. Where there is no
uncertainty value, usually the particular value has been assumed.


The coding used in the plots is as follows:

Event type
* Disappearance events are plotted as red points. 
* Reappearance events are plotted as green points.
* Miss events are plotted as grey lines.
* For some events, the predicted central path is plotted. 
   This is drawn using a purple dashed line.

Observing method
* Events recorded visually are plotted with a '+'
* Video/CCD observations are plotted with a small square.
* Miss events are plotted with a 'x'.

Plot style
The plot is drawn in a manner that depends on the detail that is derived
from the observations.

* For the best-observed events, the observations are drawn without any
best-fit ellipse, or joining pairs of observations. This better enables the
irregulaities in the asteroid profile to be visible.

* For well-observed events, a best-fit ellipse is drawn through the
observations. The ellipse illustrates the shape of the asteroid.

* For poorly-observed events, a gray line joins the events of each observer.
That is, it shows the time during which the star was invisible to the
observer.

Note:  In a few cases, if the observed chord indicates that the diameter
of the asteroid was larger than expected, a plot with only a single
chord may show a circle fitted to the ends of the chord.  Ordinarily
a fit will not be made to a single chord.


Double stars.
For a small number of events, a double star is involved. When this occurs,
the plot includes a representation of the double star, drawn on the same
projected scale as the plot of the asteroid.