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This lesson shows how to acquire a simple target for the telescope and how to accurately centre it in the field.
Acquiring a target for the telescope can be accomplished in one of two ways. Both ways involve using the mount's control program, '!TheSky'. Once the telescope has been connected and the mount has been homed it is ready to accept slew commands. Targets can be found be searching for them manually in the 'Virtual Sky' in '!TheSky'. The 'Virtual Sky' can be navigated using the green arrows on the toolbar. Since it is amateur software it is unlikely that this will be sufficient for scientific purposes. To search for fainter objects listed in scientific catalogues use the ''Find'' command. To use ''Find'' click ''Edit'' then ''Find'' or simply use the ''Ctrl+f'' key combination. A dialog box should appear. Enter the identifier off the desired target in the field at the bottom of the window. For information on the catalogues that can be used and the correct format for searching for them see [[Armagh Robotic Telescope: Telescope Operation and Observing Software#Acquiring a target | here]]. When the target has been found a window containing information about the target will appear. Observers should carefully confirm that this is the target they are looking for and then click the ''Centre'' button in the bottom left corner of the window. When the target has been centred then the observer should hit the ''Slew'' button which is a green telescope in the window. The mount will point the telescope at the target. At this time the dome should be controlled manually to allow the telescope to see out. The shutter controls are located by the shutters and the rotation controls are by the box mounted on the wall next to the computer. Slaving the dome will be covered in an advanced lesson later.
When the telescope slews to its target the target may not be in the very centre of the field. The finder telescope can be used to check that the mount is close if the object is sufficiently bright. For accurate centring the main CCD must be used. Gain Camera control through !MaxIm. A 'continuous' exposure can be used to centre the target. Click the ''Expose'' tab on the ''Camera Control Window''. On the right mark the ''Continuous'' option. Set the exposure time to a reasonable value given the brightness of the object. It is not important if the object saturates at this point. Choose the ''No Filter'' option for the clearest view of the object. Now click the ''Start'' button. Carefully examine the field for the given target. Be aware that the camera may not be orientated in the same way as you expect, the image must be examined from all angles. If the target is in the field then the mount's joystick can be used to carefully bring the target into the centre of the field. Move the joystick only in tiny amounts to begin with so that the effect of different movements can be seen on the screen. The computer should be continuously be downloading images and updating the display. If the object is lost altogether then issue a slew command to the telescope from 'TheSky' so a second attempt can be made. When the target is centred then observations can begin.
Centring the target with the joystick can be quite tricky. Here are some tips on how to centre the target successfully.
Always hold the joystick in the same orientation in your hands. This means that the movements made with the joystick will normally produce similar results from target to target.
Use very slight movements at first to gain an understanding about how the joystick affects the position of the target in the field. This prevents the target from being lost from the field altogether.
When the telescope changes which side of the mount it is pointing to it performs a 'meridian flip'. This means that one joystick movement on the west side of the mount will not produce the same result when pointing on the east side of the mount. Always be careful when the telescope has flipped.
For imaging purposes the auto-guiding process should be started now. This will be covered in an upcoming lesson. The imager should select the appropriate exposures he wishes to make. This will be covered in the next lesson.
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