What Is an Equatorial Mount Telescope?

Equatorial mounts are made to improve the shortcomings of floor level devices. Its main purpose is to overcome the influence of the rotation of the earth on stargazing. A standard set of astronomical telescopes often consists of telescopes, equatorial mounts, tripods and other components.

This speed is 360 degrees per day (because the earth makes one revolution per day). This is called automatic tracking. Of course, if you use a manual equatorial mount, you have to adjust the right ascension (or hour angle) knob at regular intervals. The declination does not need to be adjusted. (Also fine-tune the declination). No need to adjust two axes at the same time for easy tracking, this is the fundamental reason to use the equatorial mount

Many popular books on astronomy will teach you to find the stars by calculating the hour angle. According to my experience, it is not convenient to use the hour angle when doing amateur observation. Because you have to calculate the star first, you also need to know the right ascension of the celestial body. Declination value. Coupled with the accuracy of the hour angle plate, it is not as easy to find stars in this way as using star charts.

So, only for fixed telescopes with fixed bases and polar axes aligned, and

There are many different types of equatorial devices, mainly:

German style

Commonly used for refraction telescopes with longer barrels. Declination axis

General equatorial motors only use the stellar speed for tracking; some higher-grade equatorial instruments will include the moon speed, the sun speed, and even the emperor speed to achieve a more ideal tracking effect.

The picture shows the German-style equatorial mount displayed in the public hall in the Taipei City Astronomy and Science Education Museum. According to different needs, the equatorial mount has various designs, and each design has its advantages and disadvantages.

Equatorial mounts rarely use electricity as a source of power for automatic tracking. Japan has sold winding products. The manual method, because it allows the number of rotations to be determined by the number of rotations of the handle, which is especially useful for finding some dark stars.

It is said that

The biggest feature of the equatorial mount is that one of its rotation axes (the right ascension axis) is parallel to the earth's rotation axis.

The function of the equatorial mount is relative to that of the theodolite. Although everyone should have already understood it, there is still something worthy of consensus, that is, it is a easier to track platform than the theodolite. Just turn one axis That's it. However, such convenient tracking has to pay a considerable price, and the more it is required, the greater the cost. As far as the German equatorial instrument accompanying many older generations in Taiwan who have spent most of their lives since the Japanese Occupation Period, its weight ca nt be used to look at the stars, which is quite troublesome; nevertheless, the fork equatorial instrument There is no such problem, but it still cannot be favored by most of Taiwan's peers, so we must make it clear.

Although the dead angle of the fork equatorial mount in the celestial south and north poles is worth mentioning, at least it does not affect the operation of the equatorial mount. It will not be more fatal to see that the German equatorial mount gets stuck in the frame when it is turned. So using the term "dead corner" to avoid using the fork-type equator does not seem to be a perfect argument. It's funny to say, in fact, my guess is that this phenomenon is mainly caused by "to the polar axis". Prior to the return of Halley's comet, the number of similar goodies was very small, and astrophotography was not carried out. In these same good eyes, the polar axis used by the "dial method" has been quite accurate.

Since the introduction of Takahashi's P-type equator, etc., it is hoped that it will become a German-type equator every year. Even a fork-type equator can not avoid such optional accessories. A few years after Taiwan s early equatorial instruments such as P-2, TS-90, and MARK-X entered Taiwan, Halley's comet returned, and then someone would understand the polar axis correction method such as the dial method, even if it was intentionally done, It is not necessary to find the required scale on the equatorial mount, and it is not very accurate anyway.

When it comes to the polar axis, you must know that aligning the polar axis is necessary for photographers. The reason why the German equatorial mount is easy to polarize is that besides it is easy to build extreme hope, it also allows longer polar axis. One, relatively speaking, in addition to the commercially available fork-mounted equatorial mount, it is expected to be installed outside, which may increase the relative error. Its short polar axis is also a difficulty in mechanical construction ^[4] .