Finding the North Celestial Pole

In each hemisphere, there is a point in the sky around which all the other stars appear to rotate. These points are called the celestial poles and are named for the hemisphere in which they reside. For example, in the northern hemisphere all stars move around the north celestial pole. When the telescope's polar axis is pointed at the celestial pole, it is parallel to the Earth's rotational axis.

Figure 7-5

The position of the Big

Dipper changes throughout

the year and the night.

Many methods of polar alignment require that you know how to find the celestial pole by identifying stars in the area. For those in the northern hemisphere, finding the celestial pole is not too difficult. Fortunately, we have a naked eye star less than a degree away. This star, Polaris, is the end star in the handle of the Little Dipper. Since the Little Dipper (technically called Ursa Minor) is not one of the brightest constellations in the sky, it may be difficult to locate from urban areas. If this is the case, use the two end stars in the bowl of the Big Dipper (the pointer stars). Draw an imaginary line through them toward the Little Dipper. They point to Polaris (see Figure 7-5). The position of the Big Dipper changes during the year and throughout the course of the night (see Figure 7-5). When the Big Dipper is low in the sky (i.e., near the horizon), it may be difficult to locate. During these times, look for Cassiopeia (see Figure 7-6). Observers in the southern hemisphere are not as fortunate as those in the northern hemisphere. The stars around the south celestial pole are not nearly as bright as those around the north. The closest star that is relatively bright is Sigma Octantis. This star is just within naked eye limit (magnitude 5.5) and lies about 59 arc minutes from the pole.

Definition The north celestial pole is the point in the northern hemisphere around which all stars appear to rotate. The counterpart in the southern hemisphere is referred to as the south

celestial pole.

Figure 7-6

The two stars in the front of the bowl of the Big Dipper point to Polaris which is less than one degree from the true (north) celestial pole. Cassiopeia, the “W” shaped constellation, is on the opposite side of the pole from the Big Dipper. The North Celestial Pole (N.C.P.) is marked by the “+” sign.

NexStar HC specifications

The Celestron NexStar Hand Controller (HC) is an advanced control unit designed to enhance the astronomical observation experience for both novice and experienced stargazers. This innovative device is an integral part of the NexStar telescope series and offers a range of features that simplify the process of locating celestial objects.

One of the main features of the NexStar HC is its user-friendly interface. The controller is equipped with a large, illuminated LCD screen that displays essential information clearly, even in low-light conditions. The layout is intuitive, allowing users to quickly familiarize themselves with its functions. The keypad includes dedicated buttons for common tasks, making it easy to navigate the expansive database of celestial objects.

The NexStar HC boasts an impressive database containing over 40,000 celestial objects, making it a powerful tool for astrophotography and observational astronomy. Users can access planets, stars, galaxies, and nebulae at the touch of a button. The built-in database allows for precise and efficient locating of objects, significantly reducing the time spent searching the night sky.

One of the standout technologies featured in the NexStar Hand Controller is the GoTo functionality. This advanced tracking technology enables the telescope to automatically locate and track celestial objects with high precision. By entering the desired object into the controller, users can allow the telescope to autonomously adjust its position, providing a hassle-free experience.

Additionally, the NexStar HC supports various alignment methods, including SkyAlign, AutoAlign, and One-Star Align. These alignment techniques assist in calibrating the telescope for optimal tracking and positioning. The SkyAlign method, in particular, allows users to point the telescope at any three bright stars, and the HC will calculate the telescope's location in relation to those stars, making alignment accessible even for beginners.

The NexStar Hand Controller is also compatible with Celestron’s StarSense technology, enabling automatic alignment using a smartphone. This feature allows users to refine their observations seamlessly and provides a modern twist to traditional stargazing methods.

Other notable characteristics include programmable go-to tracking speeds and the ability to save user-defined locations. The controller’s ergonomic design ensures comfort during long observing sessions, while the robust build quality guarantees durability.

In summary, the Celestron NexStar Hand Controller combines a wealth of features and cutting-edge technologies to enhance the stargazing experience. Its user-friendly interface, extensive database, versatile alignment methods, and compatibility with advanced tracking systems make it an indispensable tool for anyone looking to explore the wonders of the night sky.