Sky-Watcher Telescope Mount Polar

[Philosophaie]

I just got a Sky-Watcher 130mm EQ2 Reflector Telescope. The mount does not have any Polar markings. Humor me and tell me which way is North when RA=0. Or could you please explain the Right Ascension, RA dial. I think I have the lower Declination dial down but the upper Declination dial is a little confusing also.

[Merlin66]

Google is your friend......

Equatorial coordinate system - Wikipedia, the free encyclopedia

The Dec circles on the mount show the declination both north of the equator and south. ie +20 is north - towards the pole star and -20 is towards the horizon.

RA=0 is like the Greenwich meridian on the earth - just a fixed (well relatively) point to measure from.

HA (Hour angle) is the distance in RA from the meridian ie your north south line - a HA=6 is the East or west horizon.

[barkis]

When you have your polar axis set, ie, the mounts Right Ascension axis is pointing to the North Celestial pole, you can set your declination circle to a known star. Look up its declination, for example Vega dec. = +38 deg. 44 minutes, with the star in the centre of your eyepiece, turn your dec. circle to read the dec. of the star. It can then be locked and not moved again.

Providing you carefully mark the position of your mount, the tripod legs where they can be positioned in the same place every time you setup, then the dec circle can remain fixed.If you wish to locate another object, and you know it is in the sky, turn the dec. axis to it's angle in deg and minutes, then carefully sweep your scope around around with a low power EP in, and the chances are you will locate the object. If you turn the dec. to read zero degrees on the scale, pointing south. Your scope will be pointing to the Celestial equator, which is a projection of earths equator out in space.

Using small setting circles can be a bit time consuming, especially when they are usually so small. they can be hard to read at night, and using a torch will spoil your night vision, unless you mask it with a red filter. Don't let fiddling with the circles spoil your enjoyment.

As you gain more experience in observation, you can teach yourself star hopping techniques in order to find objects. It takes time, but it can be done. Get yourself a good Planisphere, and a book of star maps.

Good Luck.

Ron.