Reference Lines dialog box (View | Reference Lines)

Use these options to turn on and off all the different types of reference lines.

General Lines Group

This group contains options for turning on and off reference lines.

Ecliptic

Turns on or off the line that indicates the path of the sun. In the 3D Solar System Mode, this line is displayed as a plane defined by Earth’s orbit.

Galactic Equator

Turns on or off the line that is drawn along the equator of the Milky Way.

Milky Way Picture

Turns on or off the photograph of the Milky Way.

Milky Way Solid

Turns on or off the region that depict the extents of our galaxy, the Milky Way.

Constellation Group

This group contains options for turning on and off constellation lines and drawings.

Lines

Mark this option to turn on the lines that connect stars of each constellation, giving a rough trace of its mythological shape.

Boundaries

Turns on or off the lines that represent the boundary of each constellation.

Drawings

Turns on or off the pictures (or digitized drawings) that represent each constellation.

Only Near Screen Center

Mark this option to show the constellation photograph of the constellation at the center of the screen only. Clear this option to show all constellations on the Virtual Sky.

Equatorial Lines Group

Grid

Turns on or off the lines following right ascension and declination.

North/East Indicator

Turns on or off a small graphic that is shown in the upper left corner of the Virtual Sky that indicates the compass directions North and East.

Spacing

Grid spacing represents the increment of right ascension and declination at which lines are drawn and labeled. The three equatorial grid spacing options are described below.

Automatic - Wide

Select this option to automatically display wide-spaced grid lines at all fields of view.

Automatic - Fine

Select this option to automatically display narrow-spaced grid lines at all fields of view.

User-Defined

Draws grid lines at user-defined increments as specified in the RA and Dec. Spacing text boxes.

RA Spacing

Input the spacing increment that specifies where lines of right ascension are displayed. For example, an RA spacing of 1.0 will show a grid line at every hour of right ascension.

Dec. Spacing

Input the spacing increment that specifies where lines of declination are displayed. For example, a Dec. spacing of 1.0 will show a grid line at every degree of declination.

Note: The User defined spacing increment is limited by the current field of view to prevent "overcrowding" of the grid lines. If you enter small increment, say, 0.10, you will not see this coordinate grid spacing until the field of view is smaller than about 5 degrees.

Telescope Limit Lines Group

This group contains options for editing and turning on and off telescope limit lines. These lines represent regions that the telescope cannot slew.

Visible

Mark this option to display telescope limit lines.

Edit Declination Limit

The declination limit is an area of the sky that defines where, in declination, a computer-aided telescope cannot slew to. Click this button to use the Horizon Line Editor to define the declination limit horizon line.

Edit Altitude Limit

The altitude limit is an area of the sky that defines where in altitude (or relative to a local horizon) a computer-aided telescope cannot slew to. Click this button to use the Horizon Line Editor to define the altitude limit horizon line.

Horizon-Based Lines Group

This group contains options for displaying lines that are based on the local horizon (altitude and azimuth coordinates).

Grid

Mark this option to display a horizon-based coordinate grid.

Meridian

Displays a line that runs from due South, through the zenith to due North. An object "transits," or reaches its highest point in the sky, when it passes this imaginary line.

Local

Mark this option to display a line that represents the local horizon.

Local Horizon Fill Group

This group contains options that determine how the local horizon is filled.

Transparent

Mark this option to fill the local horizon so that objects below the horizon are still visible.

Opaque

Mark this option to fill the local horizon so that objects below the horizon are not visible.

Panoramic

Mark this option to display a photograph of the local horizon. See the Real Mode Options command for details about selecting the local horizon photograph.

Refracted

Mark this option to display a line that represents the local horizon with refraction (atmospheric bending of light).

Show in Pole-Up Orientation

Mark this option to display the local horizon when TheSky is using an equatorial based orientation.

Edit Local Horizon

Click this button to display the Horizon Editor that is used to draw your local horizon.