Use the Aim settings panel to center your view on any object in space. The Aim
panel also controls the zoom factor and the base plane against which space objects
are viewed.
Use the lock button in the
top right of the Aim panel to lock your view on the currently
selected object. You can also lock your view on an object by clicking Lock in the
Object Info window. The lock button only works if you have already centered on an object.
Locking your direction of view is useful if you want to track the motion of an object such
as a planet or moon. If you center on a planet or moon and then run time tracking without
locking your view on the object, the object may move from the center of the sky window.
Click the re-size button to
display/hide the co-ordinates settings and base plane boxes.
The name of the currently centered object is displayed in the Target object box.
The Target object box displays a locked symbol
when the direction of view is locked on an object.
The co-ordinates of the center of the screen are generally expressed relative to the celestial
equator (the Right Ascension/ Declination system). If you are using Observe from surface
mode, you can also display the co-ordinates of the center of the screen relative to the
horizon (the Azimuth/ Altitude system).
For an explanation of the Right Ascension/Declination and Azimuth/Altitude co-ordinates
systems, please see the relevant entries in the online version of the Penguin Dictionary of
Astronomy.
Right Ascension/Declination (or Azimuth/Altitude) are set using three fields: direction
(+/-), degrees or hours and minutes.
You can enter new viewing direction co-ordinates by editing the values in the Right
Ascension/Declination (or Azimuth/Altitude) fields. Each value in the box operates as a
separate field. Click a value to select it then type
new values. Use the tab key to step through each of the fields. Press Return/Enter to
apply the new direction of view.
Alternatively, you can select a preset value from the co-ordinates settings pop-up menu.
You can move your viewing direction through a sequence of positions using the
Control panel (Direction mode).
Alternatively, you can select a preset value from the co-ordinates settings pop-up menu.
The Sky window view in RedShift is always oriented (its tilt is controlled) relative to a
particular base plane. By default, the appropriate base plane is chosen for the present
Location mode. You may wish, however, to vary the slope of the display. The base plane
controls allow you to do this in a variety of ways. A new feature of RedShift 3 is the
ability to control the roll angle relative to the selected base plane.
Click the re-size button in the top right of the Aim panel to display the Select base plane
pop-up menu and the Roll angle box.
Use the Select base plane pop-up menu to choose one of six different base plane settings:
Horizon plane - the local horizon when in Observe from surface mode
Celestial equator
Eq. Object - the equator of the object which the current location relates to (i.e. the
Earth's equator if location is currently set to the Earth's surface or tracking Earth)
Ecliptic plane
Galactic plane
Note that the available base plane settings vary depending on the location mode currently
selected.
Use the Roll angle field to enter the value of the roll angle relative to the currently
selected base plane.
Click the field in the roll angle box to select it. Enter a new value.
Press return/enter to apply the new value.
The Roll angle is counted from the base plane clockwise (+) or counter-clockwise (-).
By default, the base plane is locked; this means that as the view changes, the roll angle
relative the base plane is fixed. In some cases you may wish to unlock the roll angle.
Zoom controls the angle of view that is displayed. Increasing the zoom factor decreases the
area of sky that is displayed.
Note that resizing the Sky window (main RedShift window) changes the angle of view, but does
not change the zoom factor (i.e. it does not change the angular separation between objects
in the Sky).
Edit the value in the Zoom field to increase or decrease the Zoom factor.RedShift 3 lets you enter
a zoom factor anywhere between 0.2 and 9999. Click the value
in the zoom field to select it. Enter the new value. Press return/enter to apply the new
value. Or select one of the pre-set values from the zoom factor pop-up menu.
The Zoom factor can also be changed using the + and - keys on the keyboard or by using Zoom
mode in the Control panel.
Zoom factor 1 shows
roughly the amount of sky that your eye takes in. This is quite a wide angle view for the
computer screen, so objects seem smaller than normal. Choose a zoom factor of 3.5 to make
objects seem roughly normal size. Bear in mind that setting a very large zoom factor may
result in nearby planets and moons obscuring your view.
If you know the name of the object you want to observe (such as a planet, a star or a
comet) use the Select target object pop-up menu in the Aim panel. Click the name of
an object in the sub-menus to center your view on it. If the object you want to observe
isn't on the menu choose Find object to open the
Find object dialog to find an object in the RedShift catalogues.
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