Using Your Telescope- Astronomical Observing

a.		b.

c.		d.

Figure 10. This illustration shows the telescope pointed in the four cardinal directions: (a) north, (b) south, (c) east, (d) west. Note that the tripod and mount have not been moved; only the telescope tube has been moved on the R.A. and Dec. axes.

Figure 10 illustrates how the telescope will look when pointed at the four cardinal directions—north, south, east and west.

The key things to remember when pointing the telescope are that a) you only move it in R.A. and Dec., not in azimuth or lat- itude (altitude), and b) the counterweight and shaft will not always appear as it does in Figure 1. In fact it almost never will!

6.Using Your Telescope— Astronomical Observing

Choosing an Observing Site

When selecting a location for observing, get as far away as possible from direct artificial light such as streetlights, porch lights, and automobile headlights. The glare from these lights will greatly impair your dark-adapted night vision. Set up on a grass or dirt surface, not asphalt, because asphalt radiates more heat. Heat disturbs the surrounding air and degrades the images seen through the telescope. Avoid viewing over rooftops and chimneys, as they often have warm air currents rising from them. Similarly, avoid observing from indoors through an open (or closed) window, because the tempera- ture difference between the indoor and outdoor air will cause image blurring and distortion.

If at all possible, escape the light-polluted city sky and head for darker country skies. You’ll be amazed at how many more stars and deep-sky objects are visible in a dark sky!

Cooling the Telescope

All optical instruments need time to reach “thermal equilibri- um.” The bigger the instrument and the larger the temperature change, the more time is needed. Allow at least a half-hour for your telescope to cool to the temperature outdoors. In very cold climates (below freezing), it is essential to store the tele- scope as cold as possible. If it has to adjust to more than a 40° temperature change, allow at least one hour.

Aiming the Telescope

To view an object in the main telescope, first loosen both the R.A. and Dec. lock levers. Aim the telescope at the object you wish to observe by “eyeballing” along the length of the telescope tube (or use the setting circles to “dial in” the object’s coordinates).Then look through the (aligned) finder scope and move the telescope tube until the object is generally centered on the finder’s crosshairs. Retighten the R.A. and Dec. lock levers.Then accurately center the object on the finder’s crosshairs using the R.A. and Dec. slow- motion controls. The object should now be visible in the main telescope with a low-power (long focal length) eyepiece. If neces-

120 EQ specifications

The Orion 120 EQ telescope is a testament to modern astronomy, designed to provide both novice stargazers and seasoned astronomers with an exceptional viewing experience. With a 120 mm aperture, this telescope offers a bright and clear image, making it ideal for observing celestial objects such as the Moon, planets, and deep-sky wonders.

One of the standout features of the Orion 120 EQ is its optical design. The telescope uses a robust refractor setup, which is renowned for delivering high-quality images with minimal distortion. The fully coated optics enhance light transmission, ensuring that the views are not only bright but also rich in detail. This is particularly beneficial when exploring intricate lunar craters or the rings of Saturn.

The 120 EQ comes equipped with a sturdy equatorial mount that simplifies the tracking of celestial objects as they move across the night sky. With its smooth movements and precise adjustments, users can easily keep their target in sight, making it an excellent choice for astrophotography enthusiasts and visual observers alike. The mount also features a built-in polar scope, aiding in accurate alignment for observers in various geographic locations.

Additionally, the Orion 120 EQ includes high-quality eyepieces that maximize the telescope's optical capabilities. With different magnification options, users can switch between wide field views and detailed close-ups, making it versatile for various types of astronomical observation. The eyepieces are designed for comfort and ease of use, allowing for extended viewing sessions without causing strain.

Portability is another key characteristic of the Orion 120 EQ. Despite its robust performance, the telescope is relatively lightweight and can be easily transported to dark-sky locations, which is crucial for avoiding light pollution and enhancing the viewing experience. Its compact design ensures that it can fit into most car trunks, making it an ideal companion for astronomy outings.

The ease of setup is also noteworthy. The Orion 120 EQ is designed with user-friendliness in mind, enabling both beginners and experienced users to get started with minimal effort. The included user manual provides helpful tips and guidance, making it simple to start exploring the night sky in no time.

In summary, the Orion 120 EQ is a remarkable telescope that combines quality optics, a dependable equatorial mount, and user-friendly features. Whether you're just starting your astronomy journey or are looking to enhance your existing collection, the Orion 120 EQ provides the necessary tools to explore and appreciate the wonders of the universe. Its performance, portability, and ease of use truly set it apart in the world of amateur astronomy.