Using the Setting Circles

Setting Circles are dials (or gauges) for right ascension and declination that allow you to locate celestial objects easily from their coordinates as listed in a star chart or atlas.

1.The declination setting circle (see Figure 9) is scaled in degrees and the right ascension setting circle is incremented in minutes. The circles will get you close to your target but not directly on it. Also, the accuracy of your polar alignment will affect how accurate your setting circles read.

2.The declination setting circle is factory set and should not need any adjustment if it reads accurately.

3.The right ascension setting circle must be aligned. Choose a bright and easy to find star in a star chart and note the coordinates (right ascension and declination). Find the star in the Star Pointer and then in the telescope. Now, rotate the right ascension circle to match the coordinates of the star with the indicator mark. If you polar aligned the telescope accurately, the declination circle should be correctly set to the proper coordinates.

4.The right ascension setting circle does not move as the telescope moves in right ascension and thus it must by aligned each time you want to use it to find a new object. However, you do not need to use a bright star each time but you can use the object you are currently observing.

5.Now, using a star chart or atlas you can find numerous objects. First move the telescope in declination to the correct declination coordinate. Then move the telescope in right ascension until the indicator points to the correct coordinate.

6.After moving the telescope to the correct celestial coordinates, look through the lower power eyepiece to see if you have located the object you wish to view. Center the object in eyepiece. If the object is not visible in the eyepiece, gradually pan the telescope, using the right ascension and declination cables, until the object is visible. Always start by using your lowest power eyepiece (20mm) then switching to higher power once you have found the desired object.

Magnification

The magnification (or power) of a telescope varies depending upon the focal length of the eyepiece being used and the focal length of the telescope.

The PowerSeeker 127 telescope has a focal length of 1000mm and comes with a 20mm 1¼" eyepiece. To calculate magnification, use the following formula, in which FL = focal length:

FL (telescope) in mm

Magnification = FL (eyepiece) in mm

Therefore, if you use the 20mm eyepiece your magnification is 1000/20 = 50x. The same formula can be applied to Important! any of your eyepieces.

Magnification through any telescope has its limits. These limits are determined by the laws of optics and the nature of the human eye. Most of your viewing will be done in the range of 50x to 130x. Higher powers are used mainly for lunar and sometimes planetary observing where you can greatly enlarge the image and the atmospheric conditions are near perfect. The images at extremely high powers magnify the image, but remember that the contrast will be very low due to the high magnification. For the brightest images with the most contrast, start by using the lower power eyepiece with a smaller image scale.

The following magnification levels can be achieved when using the standard eyepieces in conjunction with the 3x Barlow lens:

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Celestron 127 manual Using the Setting Circles, Magnification
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127 specifications

The Celestron 127 is a highly regarded telescope within the Celestron family, known for its combination of portability, reliability, and versatility. This telescope is specifically designed to cater to both novice astronomers and seasoned observers, making it a popular choice for those looking to explore the night sky.

One of the standout features of the Celestron 127 is its 127mm aperture. This size is optimal for gathering light and allows users to observe celestial objects in great detail, from the craters of the Moon to distant galaxies. The telescope employs a Maksutov-Cassegrain design, which strategically combines mirrors and lenses to create a compact and efficient optical system. This design minimizes chromatic aberration while providing impressive image quality, ensuring that celestial objects appear sharp and clear.

The Celestron 127 offers a focal length of 1500mm, resulting in a focal ratio of f/11.8. This relatively long focal length is advantageous for high-power observations, making it possible to view planets in stunning detail. For instance, users can clearly see Saturn's rings or the surface features of Mars with the right eyepieces.

Portability is another major aspect of the Celestron 127. Weighing in at approximately 11 lbs, it is lightweight enough to be transported easily to dark sky locations, yet sturdy enough for regular use. The telescope comes mounted on a stable, easily adjustable mount that allows for smooth tracking of celestial objects as they move across the night sky.

Celestron integrates advanced technologies into the 127 model to enhance user experience. The telescope is compatible with various Celestron accessories, including computerized mounts for automatic tracking and GoTo functionality. This feature is especially user-friendly for beginners, who may struggle with manually locating objects.

The Celestron 127 is not only limited to astronomical observations; it can also be used for terrestrial viewing. The additional versatility allows users to take advantage of the telescope's optical capabilities during the day.

In summary, the Celestron 127 stands out as a well-rounded telescope that marries portability with advanced optical technology. With its generous aperture, Maksutov-Cassegrain design, and user-friendly features, it is an excellent choice for anyone eager to discover the wonders of the universe, whether it's their first telescope or an addition to a growing collection.
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