Meade RCX400TM Terrestrial Observing, Observing Using Autostar IIs Arrow Keys, Slew Speeds

NEVER point

the telescope directly at or near the Sun at

any time! Observing the Sun, even for the smallest fraction of a second, will result in instant and irre- versible eye damage, as well as physical damage to the telescope itself.

Warning:

Do not look through the tele- scope's eyepiece or viewfind- er while it is rapidly moving.

Children should always have adult supervision while observing.

Tip:

The slowest speed, 1x, may be changed using the Guiding Rate menu. This menu allows you to change the speed by entering a percentage of the speed (either more or less than 100%). This function may be useful in guiding the tel- escope during CCD and long-exposure photography. See GUIDING RATE, page 34, for more information.

You can also observe stars and objects in the night sky using this method, but note that objects begin to slowly drift across the eyepiece field. This motion is caused by the rotation of the Earth. As you become familiar with the Autostar II handbox opera- tion, you can counteract the drift using the automatic tracking feature in the Autostar

IISetup menu (see TO TRACK AN OBJECT AUTOMATICALLY, page 22), or by using Autostar II's GO TO capabilities (see GO TO SATURN, page 24).

Terrestrial Observing

The RCX400 models are excellent high-resolution terrestrial (land) telescopes. Viewing terrestrial objects requires looking along the Earth's surface through heat waves. These heat waves often cause degradation of image quality. Lower power eye- pieces, like the UltraWide 24mm, magnify these heat waves less than higher power eyepieces. Therefore, lower power eyepieces provide a steadier, higher quality image. If the image is fuzzy or ill-defined, reduce to a lower power eyepiece, where the heat waves do not have such an effect on image quality. Observing in early morning hours, before the ground has built up internal heat, produces better viewing conditions than during late afternoon hours.

Observing Using Autostar II's Arrow Keys

You may observe land and astronomical objects using Autostar II's Arrow keys to move the telescope.

1.Tighten the R.A. and Dec. locks (13 and 17, Fig. 1a).

2.Verify that Autostar II is properly connected to your telescope. See TO CONNECT AUTOSTAR II, page 17.

3.Flip the telescope power switch to the ON position.

The Autostar II screen is activated and a copyright message displays briefly, followed by a short beep. Then Autostar II takes a few moments to start up the system.

4.A message displays that warns not to look at the Sun. At the end of this mes- sage, press the key prompted by Autostar II to signify that the message has been read and understood.

5."Automatic Alignment" displays.

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

7.Press the Speed key (Number key "1") and then a Number key (6, Fig. 2) to change the telescope’s slew speed. ("1" is the slowest speed, "9" is highest speed.)

8.Use the viewfinder (21, Fig. 1a) to locate an object and practice using the Autostar II’s Arrow keys to center the object in the telescope’s field of view.

9.Bring the object into focus.

Slew Speeds

Autostar II has nine slew speeds that move the optical tube at rates that are directly pro- portional to the sidereal rate and have been calculated to accomplish specific functions. Press the Speed key (Number key "1") and then press a Number key to change the slew speed, which is shown for about two seconds on Autostar II’s display.

The nine available speeds are:

Number Key 1	=	1x	=		Guide Rate, programmable (see Tip at left)
Number Key 2	=	2x	=	2	x sidereal (0.5 arc-min/sec or 0.008°/sec)
Number Key 3	=	8x	=	8	x sidereal (2 arc-min/sec or 0.033°/sec)
Number Key 4	=	16x	=	16	x sidereal (4 arc-min/sec or 0.067°/sec)
Number Key 5	=	64x	=	64	x sidereal (16 arc-min/sec or 0.27°/sec)
Number Key 6	=	128x	=	30	arc-min/sec or 0.5°/sec
Number Key 7	=	1.5° =		90	arc-min/sec or 1.5°/sec
Number Key 8	=	3° =		180	arc-min/sec or 3°/sec
Number Key 9	=	Max =		480	arc-min/sec or 8°/sec)

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.

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