User`s guide

88 Starry Night User’s Guide
Semi-major axis: This is the distance
between an object and its parent body, at
the point when the object is farthest away
from the parent body. For a circular orbit,
the semi-major axis is equal to the orbital
radius.
Tip: Click-hold and drag a columns name
towards the left or right to move the
column into a new position. You can also
add or remove a column by right-clicking
on its name. This will open a contextual
menu allowing you to check/uncheck the
columns you wish to display.
Object Contextual Menu
An object’s contextual menu provides a
list of actions in Starry Night that can be
performed on an object. You open an
object’s contextual menu by clicking the
right mouse button (Ctrl-clicking on the
Macintosh) while the cursor is pointing at
the object.
All of the items in the
menu relate to the
object that you clicked
on. If you were not
pointing the cursor at a
specific object, the
menu gives you
options for the
appearance of the sky
as a whole and the
constellation which
you are pointing at.
See “Sky Contextual Menu
” on page 33
for information on that menu.
Tip: You can also open an object’s
contextual menu from the Find pane. Type
in a search for the object you are
interested in, then click the arrow to the
left of the object’s name in the list of found
items.
The various options in the contextual
menu are described below. Most of these
features are discussed in more detail in
other sections of the book, so only a brief
description of each feature is given in this
section. Don’t be overwhelmed! The
options are just listed here so that you have
a quick reference for all the contextual
menu options in one place.
Select/Deselect: This selects or deselects
the object. If an object is selected, its name
and an arrow pointing to the object will
appear onscreen. See
“Labeling Select Objects
” on page 39 for
more information on selecting objects.
Centre: This adjusts your view so that the
object is at the centre of the screen and
remains locked in the centre of the screen
as time passes. This is handy if you want
to watch a planet’s motion against the
background stars, for example.
Note: If you are centred on an object and
it falls beneath your horizon, your view of
it will be obscured by the horizon.
Magnify: This zooms in on the object so
that you get a close-up view. Objects
within our solar system and deep space
objects in the Messier and Bright NGC
Objects databases all have detailed
images. Stars other than our Sun are just
shown as points of light, and many of the
objects from other databases will just have
position markers instead of images.
Go There: This changes your location to
the surface of the object in question (if the
object is a star, you will be placed nearby).