User`s guide

Basics 29
Changing the Zoom Step: If you choose
Preferences from the File menu
(Windows) or the Starry Night menu
(Macintosh) and choose Responsiveness
from the dropbox in the upper left corner
of the Preferences dialog box, you will see
a slider named “Zoom Step”. This slider
adjusts the rate at which Starry Night
increases and decreases your
magnification when you use the Zoom
buttons. By setting this slider farther to the
right, you will zoom in or out faster,
because each zoom step will be larger.
Angular Separation: Angular separation
provides another way of understanding
fields of view and angles in the sky. If you
point at an object and click and hold the
left mouse button and then drag the mouse
to a second object, a line appears which
connects the two objects. The
angular
separation
between the two objects is
displayed, along with the direction of the
line and the actual distance between the
two objects (if known).
The angular separation measures how far
apart in the sky two celestial bodies
appear. The entire sky is divided into 360°,
so an object which is directly in front of
you and an object directly behind you in
the sky have an angular separation of
180°. If you measure the angular
separation between two objects on
opposite sides of your screen, you should
find that it is very close to the field of view
that Starry Night is showing. Note that the
angular separation of two objects has no
connection to how far apart these objects
really are: two bodies which appear side
by side in the sky may be hundreds of light
years apart!
Example: Magnifying Jupiter
1Open the
Find pane and type in
“Jupiter”.
2 Double-click on Jupiter’s name in the
list to centre on Jupiter. If a dialog box
shows that Jupiter is beneath the horizon,
choose the
Best Time option.
3 If Starry Night is displaying a
daylight sky, choose
View->Hide
Daylight
from the menu to turn off day-
light.
4 Click the “+” zoom button to slowly
zoom in on Jupiter. As you zoom in, Starry
Night automatically shows dimmer stars.
Once your field of view reaches about 30
arcminutes, Jupiter will start to look like a
ball instead of a point.
5 Continue clicking the “+” zoom button
all the way until your field of view is about