Equatorial Mount?

Question

What does a Equatorial Mount do?

Answer 1

It allows you to track the sky (follow stars as they rise, cross the sky and set) by moving the telescope around only one axis, called the polar axis, if the mount's polar axis is correctly aligned parallel to Earth's axis of rotation.

Answer 2

An EQ mount has one axis aligned with the axis of Earth's rotation. Generally this is done via a low-power finder scope with a cross-hair that is on the same axis, and then pointed toward the North Star. This lets the mount swing in a tilted East-West direction. There is, of course another axis to the mount that lets the mount swing North and South.

The HUGE advantage to an EQ mount is that, if you put a small motor drive on the axis pointing North, and this motor is geared down to drive the axis one revolution per 24 hours, the mount will nullify Earth's rotation and therefore objects viewed will not move. I should mention that with a non-motorized and non-equatorial mount, you have to constantly adjust the scope in both axis to keep an object in the eyepiece. This is anything from a minor annoyance particulary at high magnification to a serious obstacle for long-exposure astrophotography.

Another advantage to an EQ mount is that star charts locate objects as to coordinates translatable to an EQ mount. With a non-EQ mount, you usually have to starhop to find a particular object, something that takes experience and familiarity with the portion of sky of interest.

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Answer 3

An equatorial mount has its main axis parallel to the Earth's axis so that, as the Earth rotates in one direction, the mount rotates in the opposite direction, keeping the telescope pointed at the same point in the sky. Essentially it neutralizes the Earth's rotation. It is primarily required for astro-imaging, though it offers some convenience for visual observing as well. On the down side, it tends to be heavier and more complicated to use than an altazimuth mount, such as is found in Dobsonian telescopes.

Answer 4

A t'scope mount (usually motorized) with an axis parallel to the axis of the earth. This provides easy tracking of sky objects and for photography when combined with a clock drive.

Answer 5

It allows you to move your scope in a path that matches the earth's rotation. You must point the axis of rotation at the North Star for this to work. It also has a counterweight to balance the weight of the telescope, so it won't try to tip by itself.