Two radii for the ellipse, in the same units as the
position coordinates (which is degrees for the sky plot).
It doesn't matter whether the major one is larger than the minor one.
Orientation
Position angle in degrees.
For the plane plot it is the angle anticlockwise from the X axis
to the major radius.
For the sky plot it is the angle from the North pole to the major axis
in the direction of positive RA.
If the value is missing (either this field not filled in or blank in
the data) it is considered to be zero.
Ellipse
Ellipse shape, selected from a range of options
(includes also rectangles, crosses etc).
Scale
Changes the factor by which all ellipse sizes are scaled.
If the ellipses are too small, slide it right, if they are too big,
slide it left. The scale is logarithmic.
Auto Scale
If selected, this option will determine the default ellipse scale size
from the data - it will fix it so that the largest ellipses are a few
tens of pixels long by default.
That scaling can then be adjusted using the Scale slider.
If unselected, then the default position of the Scale slider corresponds
to the actual positions given by the submitted ellipse radii coordinates.