User`s guide

Observation Tools 121
Adding Objects to the Graph: Right-click
(Ctrl-click on the Mac) on any object and
choose Start Graphing from its
contextual menu to plot this object on the
Graph.
Changing Time On the Graph: The
horizontal axis plots time, with the current
time at the Graph’s centre. If you click in
the graph and drag an area of the Graph
onto the centre line, time in the main
Starry Night window adjusts so that this
time becomes the current time.
Graph Menu:
Right-clicking
anywhere in the Graph
opens the Graph
contextual menu.
Listed are several
preset options for
objects that you may
wish to graph (e.g.
“Inner Planets” and
several time ranges.
Also listed are the six
variables which you can plot on the
vertical axis of the graph.
Separations: This plots the angular
separation between two objects, therefore
it is only valid when you have two objects
plotted on the graph. You could use this
feature to find planetary conjunctions, for
example. By plotting Mars and Jupiter on
the Graph, you could quickly see when
these planets come closest together in the
sky.
Altitude: This plots the height of one or
more objects in relation to the horizon, so
you can quickly see when these objects are
visible. For example, if you wanted to
view 5 planets over the course of a night,
you could plot the altitude of these planets
to see when each planet will be highest in
the sky.
Magnitude: Plots the apparent magnitude
(brightness) of an object(s) over time. For
stars and deep space objects, apparent
magnitude is approximately constant.
However, the apparent magnitude of
objects in our solar system varies
considerably, due to their changing
distance from Earth. You could plot the
magnitude of an asteroid or comet to
determine when it will be at its brightest.
Distance: Plots the object’s distance from
you current position.
Elongation: Elongation plots the apparent
separation in the sky between an object in
our solar system and its parent body. It is
similar to angular separation, except
elongation has positive and negative
values, depending on which side of the
parent body the object is on. A small
elongation value means that the object’s
apparent position in the sky is very close
to its parent body, while a large elongation
value indicates that the two objects are far
apart. Planets are best viewed when they
are at fairly large elongations. In fact, this
is the only time when Mercury can be
viewed. You could also use elongation to
find the apparent position of a planet’s
moons.