using the RA axis

ive read a number of threads describing how to use the RA axis but i cant fig it out. dec is easy, its just the degrees vertical of your scope, but from what i understand, ra changes through out the night. how do you use ra? has anyone got an explination that a boulder would understand?

Hi,
If you are using RA/DEC, it makes alot of sense if using an equatorially mounted telescope.
As you say declination is up down, RA is east/west in an arc shape as the scopes base is inclinded to point at the pole (we're not talking about altaz here)
Its called RA because if you're looking at the north pole, then everything will be rising to your right which is the east.
It starts at zero hour at the pegasus/picses region and adds one hour as you go east, each hour is broken in 60 minutes and each minute into 60 seconds and so on.
If you think about its a great way of involving time into the navagation around the sky as the sky moves at 1 hour per hour, so it makes it easy to predict where things will be later on in the night.

right, so let me get it straight in my head. lets say i come out at 10pm. I set my telescope to 0 RA and point it towards the 0 RA position in the sky. then at 11pm, anything that was at 1h RA will now be at 0RA. so for each hour i am out i either add/subtract an hour from the position of the objects as it is recorded in my star atlas. is this correct?

Thats pretty much it.
One you get a good bearing in the sky, you can move the axis to any point in the sky and the RA setting circle will tell you where you are.

does my scope have to be polar aligned to be able to use co-ordinates? ( at the correct angle for my location on the earth?)

does my scope have to be polar aligned to be able to use co-ordinates? ( at the correct angle for my location on the earth?)

If your scope isn't polar aligned then it's not RA/Dec but Alt/Az you're using. The correct angle is your latitude. So in Ireland in or around 53 degrees.