User`s guide

Appearance of the Sky 41
dimmest star that your telescope can make
out, setting the “Dimmer” end of the slider
to this magnitude gives you a good idea of
what you can view through your
instrument.
Tip: The “Constrain” function only
displays a subset of the objects that would
be shown if this function was turned off.
For example, assume you want to increase
the number of stars onscreen so that all
stars brighter than magnitude 7 are
visible. If you are at a 100° field of view,
then Starry Night will only show stars up
to a magnitude of 5.7, by default.
Increasing the apparent magnitude range
using the “Constrain” function would
have no effect. To increase the number of
stars shown, you would first move the
“Show” slider farther to the right (so that
stars as dim as magnitude 7 are now
visible), and then use the “Constrain”
function to ensure that no stars dimmer
than magnitude 7 are shown.
Many databases have unique options. We
will look at these options in the next few
sections.
Star Display Options
There are more options for displaying stars
than for any other database of objects in
Starry Night. Many of these options can be
turned on/off from a checkbox in the
Options pane, while clicking the option
name will often open a dialog box with
more controls.
Limit by Distance/Magnitude: These
options let you set up Starry Night to
display only those stars whose distance
from Earth or whose apparent magnitude
(brightness) fall within a certain range.
One use of this function would be to
identify which bright stars are within 100
light years (for example) of Earth.