Figure 8
The celestial sphere seen from the outside showing R.A. and DEC.

.

Actual image as seen with the

unaided eye

Inverted image, as viewed with the eyepiece directly in telescope

Figure 7

Focusing

To focus your telescope, simply turn the focus knob located directly below the eyepiece holder. Turning the knob clockwise allows you to focus on an object that is farther than the one you are currently observing. Turning the knob counterclockwise from you allows you to focus on an object closer than the one you are currently observing.

•If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece attached to the telescope. However, when using a camera you should always wear corrective lenses to ensure the sharpest possible focus. If you have astigmatism, corrective lenses must be worn at all times.

The Celestial Coordinate System

To help find objects in the sky, astronomers use a celestial coordinate system that is similar to our geographical coordinate system here on Earth. The celestial coordinate system has poles, lines of longitude and latitude, and an equator. For the most part, these remain fixed against the background stars.

The celestial equator runs 360 degrees around the Earth and separates the northern celestial hemisphere from the southern. Like the Earth's equator, it bears a reading of zero degrees. On Earth this would be latitude. However, in the sky this is referred to as declination, or DEC for short. Lines of declination are named for their angular distance above and below the celestial equator. The lines are broken down into degrees, minutes of arc, and seconds of arc. Declination readings south of the equator carry a

minus sign (-) in front of the coordinate and those north of the celestial equator are either blank (i.e., no designation) or preceded by a plus sign (+).

The celestial equivalent of longitude is called Right Ascension, or R.A. for short. Like the Earth's lines of longitude, they run from pole to pole and are evenly spaced 15 degrees apart. Although the longitude lines are separated by an angular distance, they are also a measure of time. Each line of longitude is one hour apart from the next. Since the Earth rotates once every 24 hours, there are 24 lines total. As a result, the R.A. coordinates are marked off in units of time. It begins with an arbitrary point in the constellation of Pisces designated as 0 hours, 0 minutes, 0 seconds. All other points are designated by how far (i.e., how long) they lag behind this coordinate after it passes overhead moving toward the west.

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Image 7
Celestron 80 manual Focusing, Celestial Coordinate System
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80 specifications

The Celestron 80, commonly referred to as the Celestron Astromaster 80, is a popular choice among amateur astronomers and nature enthusiasts alike. This versatile telescope combines portability, ease of use, and impressive optical performance, making it an excellent introduction to the world of astronomy.

One of the primary features of the Celestron 80 is its 80mm aperture. This size allows for a bright and clear view of celestial objects, even in less-than-ideal conditions. The telescope employs a fully coated optical system, which enhances light transmission and improves image clarity. As a result, users can enjoy sharp, detailed views of planets, the moon, and various deep-sky objects such as star clusters and nebulae.

The design of the Celestron 80 is particularly user-friendly. The telescope is equipped with a simple alt-azimuth mount, providing both vertical and horizontal movement. This makes it easy to track objects across the night sky. The mount is also lightweight and portable, making the telescope an ideal companion for on-the-go stargazing adventures or nature observation excursions.

Another standout characteristic of the Celestron 80 is its versatility. It comes with a couple of eyepieces, allowing users to switch magnification levels to suit their viewing preferences. The included finderscope simplifies locating celestial objects, ensuring that even novice users can quickly find and observe various targets.

The Celestron 80 also showcases advancements in technology, including its sturdy, adjustable tripod that ensures stability during use. Additionally, the telescope is designed with user comfort in mind, featuring an adjustable height to accommodate various viewing positions.

For those interested in astrophotography, the Celestron 80 offers several opportunities for capturing images of the night sky. With the proper accessories, users can attach a camera to the telescope, making it a suitable option for wide-field astrophotography.

In summary, the Celestron 80 is an excellent entry-level telescope that offers a powerful combination of features, technology, and portability. Its impressive optical performance, user-friendly design, and versatility make it a favorite among both beginners and seasoned enthusiasts. Whether you wish to observe the craters of the moon or the rings of Saturn, the Celestron 80 is poised to provide an enjoyable and fulfilling viewing experience.
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