Right Ascension Starting Point

[TheITGuy (Sean)]

Hey Guys,

Got my first telescope (Astromaster 130) and have been trying to set it up.
I have followed the guide put up by Trevor (http://www.iceinspace.com.au/index.p...63,498,0,0,1,0).
my question is, when i a set up with the telescope facing south and at the correct latitude should my RA be at 0?

[mithrandir (Andrew)]

Originally Posted by TheITGuy

Hey Guys,

Got my first telescope (Astromaster 130) and have been trying to set it up.
I have followed the guide put up by Trevor (http://www.iceinspace.com.au/index.p...63,498,0,0,1,0).
my question is, when i a set up with the telescope facing south and at the correct latitude should my RA be at 0?

Welcome to IIS, Sean.

If your scope is pointed at the SCP (south celestial pole) you can not say what the RA is because the SCP and NCP are where all meridians of RA meet.

You need to center an object with known RA and Dec and then set the circles to display that value, then if there are any lock screws tighten them. If you stop tracking (like when you pack up) you will have to repeat this process when you resume.

[TheITGuy (Sean)]

Thanks for that.
after i posted i started thinking some more. fired up the good old stellarium
As i am very new to all this i assume the moon would be something easy to align with
so hypothetically, lets go back to 6am today Bundy time

if i found the SCP - Set the latitude at 24 degrees for bundaberg
- find magnetic south and adjusted for magnetic deviation (approx 10 degrees east)
- this would give me a Declination of 90 degrees.

if i then move the DEC 83 degrees west being that the moon is at -7 degrees.
Should i then be able to rotate the RA and in that axis somewhere find the moon. and when i do knowing that it is at a RA of 12H30M adjust this dial to that time.

I hope that sort of makes sense. I am only very new at this and am still trying to get my head around it all.
thank you for your help

[LAW (Murphy)]

There's an easier way to find the moon

[Blue Skies (Jacquie)]

Originally Posted by TheITGuy

if i then move the DEC 83 degrees west being that the moon is at -7 degrees.

I think there a problem right there for starters. DEC is all about north/south. RA is east/west.

I'm on Murphy's side - MUCH easier way to do this - just point the scope at it!! I personally don't recommend trying to get your head around those dials if you're a complete beginner, I think that is the right way to do your head in and discourage you. Forget them. They are cheap and inaccurate. Instead learn were the Moon actually is by looking with your eyes. Point the telescope there. Enjoy. Repeat for other objects. Once you become familiar with how the sky works and moves, perhaps go back and try to use the dials.

[mithrandir (Andrew)]

Originally Posted by LAW

There's an easier way to find the moon

Murphy's Law?

Originally Posted by TheITGuy

- this would give me a Declination of 90 degrees.

-90 actually.

if i then move the DEC 83 degrees west being that the moon is at -7 degrees.
Should i then be able to rotate the RA and in that axis somewhere find the moon. and when i do knowing that it is at a RA of 12H30M adjust this dial to that time.

That's about right. In some ways the moon isn't a really good choice because it is about 1/2° across and moves in RA by about 2' per hour (~53' per day) so you need to accurately center it and know the RA at that time.

Blue Skies, yes Dec is n/s and RA east/west, but at the time Sean was visualizing you did have to rotate the dec axis to point the scope about 83° to the west from the SCP. If the circles are set nearly correct you can push-to a non-computerised mount and expect to get close to a target.