Meade DS-114AT instruction manual Slew Speeds, Observe the Moon, Astronomical Observing

WARNING:

Do not look through the telescope's eye- piece or viewfinder while it is rapidly moving. Children should always have adult supervision while observing.

Level the opti- cal tube

North

Fig. 18: Alt/Az Home Position.

5.The Arrow keys are now activated. Press the Arrow keys (5, Fig. 2) to slew (move) the tel- escope up, down, right, or left.

6.Press the SPEED/? key (8, Fig. 2) to change the telescope’s slew speed. See SLEW SPEEDS, below, for more information.

7.Use the viewfinder (5, Fig. 1) to locate an object and practice using the Autostar’s Arrow keys to center the object in the telescope eyepiece's field of view.

8.Use the telescope’s focus knob (1, Fig. 1) to bring the object into focus.

Slew Speeds

Autostar has nine slew speeds that are directly proportional to the sidereal rate (see TRACKING AN OBJECT AUTOMATICALLY below for a definition of "sidereal rate") and have been calculat- ed to accomplish specific functions. Pressing the SPEED/? key changes the slew speed, which is shown for about two seconds on Autostar’s display.

The nine available speeds are:
■	Speed 1	=	2x	=	2 x sidereal (0.5 arc-min/sec or 0.008°/sec)
■	Speed 2	=	8x	=	8 x sidereal (2 arc-min/sec or 0.033°/sec)
■	Speed 3	=	16x	=	16	x sidereal (4 arc-min/sec or 0.067°/sec)
■	Speed 4	=	32x	=	32	x sidereal (8 arc-min/sec or 0.13°/sec)
■	Speed 5	=	64x	=	64	x sidereal (16 arc-min/sec or 0.27°/sec)
■	Speed 6	=	0.5° =		120	x sidereal (30 arc-min/sec or 0.5°/sec)
■	Speed 7	=	1°/s =		240	x sidereal (60 arc-min/sec or 1°/sec)
■	Speed 8	=	2°/s =		480	x sidereal (120 arc-min/sec or 2°/sec)
■	Speed 9	=	Max =		(Maximum speed possible, dependent on battery power)

Speeds 1, 2, or 3: Best used for fine centering of an object in the field of view of a higher power eyepiece, such as a 12mm or a 9mm eyepiece.

Speeds 4, 5, or 6: Enables centering an object in the field of a low-to-moderate power eye- piece, such as a standard 25mm eyepiece.

Speeds 7 or 8: Best used for rough centering of an object in the eyepiece.

Speed 9: Moves the telescope quickly from one point in the sky to another.

Observe the Moon

Point your telescope at the Moon (note that the Moon is not visible every night) and practice using the Arrow keys and the slew speeds to view different features. The Moon contains many interesting features, including craters, mountain ranges, and fault lines. The best time to view the Moon is during its crescent or half phase. Sunlight strikes the Moon at an angle during these periods and adds a depth to the view. No shadows are seen during a full Moon, causing the overly bright surface to appear flat and rather uninteresting. Consider the use of a neutral den- sity Moon filter when observing the Moon. Not only does it cut down the Moon's bright glare, but it also enhances contrast, providing a more dramatic image.

Astronomical Observing

Used as an astronomical instrument, your telescope has many optical and electromechanical capabilities. It is in astronomical applications where the high level of optical performance is readily visible. The range of observable astronomical objects is, with minor qualification, limit- ed only by the observer’s motivation.

Tracking an Object Automatically

As the Earth rotates beneath the night sky, the stars appear to move from East to West. The speed at which the stars move is called the sidereal rate. You can set up your telescope to move at the sidereal rate so that it automatically "tracks" the stars and other objects in the night sky. If the telescope is not tracking an astronomical object, the object will drift out of the eye- piece field of view. The tracking function automatically keeps an object more or less centered in the telescope’s eyepiece.

To automatically track objects, you must first set the telescope in the home position, then ini- tialize Autostar, train the drive, and finally select "Targets: Astronomical" from the Autostar Setup menu. You must also learn how the Autostar keypad operates in order to move through the Autostar menus.

14