9 December 2008 15:07
- a telescope mount that looks like a "T" tilted so the base of the "T" is pointed at the celestial pole, so that as the telescope rotates around this axis (the right ascension axis), it counteracts the apparent motion of heavenly bodies due to the rotation of the earth
- the other axis is known as the declination axis, and the telescope is attached to one end, with counterweights at the other end
- also known as a GEM
- favored by amateur astrophotographers, as they allow for long exposures without field rotation
- non-motorized models have knobs (often attached to flexible cables) called slow-motion controls that users turn to keep the telescope aimed at a target
- motorized versions may have motors on one or both axes
- often have polar alignment scopes inside the right ascension axis to aid in aligning the mount with the celestial pole
- many "go-to" mounts have polar alignment routines that align the scope through iteratively aligning the scope and slewing back to Polaris
- counterweights may be added or removed, or adjusted up and down the counterweight shaft as needed to balance the weight of the optical tube(s), camera(s) and other mounted equipment
- as a safety measure, an oversized nut at the end of the counterweight shaft - aptly called a "toe saver" - hopefully prevents loose counterweights from sliding off unexpectedly
- other types of equatorial mounts include open fork, English (or yoke), and cross-axis
