User`s guide

166 Starry Night User’s Guide
Element Style (AMSAT): This is another
style used to describe the orbit of
Earth-orbiting artificial satellites. Again,
describing this format is beyond the scope
of this User’s Guide.
Reference Plane: A set of orbital elements
is not enough to describe an object’s orbit
without a reference plane. You can select a
reference plane using the dropbox in the
Orbit Editor dialog box.
For objects orbiting the Sun (asteroids,
comets, planets), the most useful reference
plane is the ecliptic plane. For objects
orbiting other planets (such as moons and
artificial satellites), the most useful
reference plane is the equatorial plane of
the object’s parent body. An astronomical
reference plane is dependent upon the time
of the observations. Starry Night allows
you to choose any of the following
reference planes:
• Ecliptic: An ecliptic reference plane
based on the time of your current Starry
Night window.
• Ecliptic 1950: An ecliptic reference
plane based on the position of the
ecliptic plane in the year 1950.
• Ecliptic 2000: An ecliptic reference
plane based on the position of the
ecliptic plane in the year 2000.
• Equatorial: An Earth equatorial
reference plane based on the time of
your current Starry Night window.
• Equatorial 1950: An Earth equatorial
reference plane based on the position of
Earth’s equatorial plane in the year
1950.
• Equatorial 2000: An Earth equatorial
reference plane based on the position of
Earth’s equatorial plane in the year
2000
• Planet Equatorial: A reference plane
based on the equatorial plane of the
object’s parent body and the time of
your current Starry Night window.
Surface/Model Tab: On this tab, you can
import a 3D model (supports .3ds models
only) or create a surface for your new
object by importing an image file. Click
Add Model to select a .3ds model from
your hard drive or Download to visit a
website that contains additional .3ds
models. Click the Add Image button to
select an image file from your hard drive.
The Delete buttons remove your custom
model or image. This button will be
greyed out if you have not yet added a
custom model or image.
Image size and appearance: There is
some restriction on image size. The
maximum size is 1500 by 1500 pixels,
while the minimum is 25 by 25 pixels. If
the picture is too big or too small, your
computer will beep twice and not allow
the paste. We recommend using images