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Astronomers sometimes use the galactic coordinate system
to pinpoint the location of an object in the Milky Way
Galaxy. Galactic latitude has its baseline of 0 along the
plane of the galaxy (the center of the Milky Way) with poles
of 90 in Coma Berenices and -90 in Sculptor. Galactic
longitude's 0 hours is located in the direction of the
center of the galaxy (in Sagittarius), increasing in an
easterly direction.
- Note: The Galactic guides
button will be inactive if none of the ecliptic guides
have been selected.
Options for the Galactic Guides
To turn on or off additional guides: a reference plane,
and the galactic meridian, equator and poles, open the
Options dialog by selecting "Options..." from the Settings
menu, then pick "Galactic Guides" from the popup menu.
Alternatively, click the options
button for Galactic Guides in the Display palette.
Show Galactic Guides: This checkbox performs a
similar function to the Guides/Galactic Guides menu command.
Check this box if you want galactic guides shown. Note: The
checkbox will be dimmed unless one of the galactic guides
has been selected.
Hide While Scrolling: To improve performance, you
can check this box so that galactic guides are turned off
while scrolling.
Galactic Poles: When checked, the galactic poles
are displayed.
Reference Plane: When checked, a galactic
reference plane is displayed, with the Sun at its
center.
Equator and Meridian
Galactic Equator: When checked, the
galactic equator is displayed.
Galactic Meridian: When checked, the galactic
meridian is displayed.
Set Color: By clicking on this button, you can
select a new color for the galactic equator and galactic
meridian guides.
Grid: Checking this box turns a galactic grid on,
and allows you to adjust how the grid is displayed. Checking
the "Number Grids" checkbox will display the galactic
latitude and galactic longitude number of each gridline.
Set Color: By clicking on this button, you can
select a new color for the galactic guides.
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