polar allignment scope for the CG Mount

Hi Guys.

Ive been navigating the skies for about 6 months now ( well only a night here and a night there) and ive taken star hopping as far as i can go for the moment. There are many many faint fuzzies i cant find by just star hopping and i want to try getting a bit more accurate. ive tried rough polar allignment myself but it didnt work well at all! so as there is a place to attach a polar allignment scope to my CG5 mount, i was wondering if someone could recommend a decently priced polar allignment scope?

If there's no slot for a polar scope, you could always drift align...

Dave

there is a slot, its a hole right up the centre of the polar axis with little thumb screws to hold in a polar allignment scope. i have tried various other techniques to get polar allignment without the scope but none have been very successful. thats why i wana give the polar allignment scope a go.

Hi Fintan.

To be honest the polar scope for the CG5 is an absolute pain to use. Three reasons for this

1) there's no illuminator so you are basically kneeling on the ground while looking through it at the back while trying at the same time to shine a red torch at the correct angle at the front. Absolutely kills your back!
2) It is a simple reticle with a small circle for Polaris.
3) Aligning the polar scope is a pain and it will move if it gets a bump, which is very easy to do when you are try to look through it.

I had one and got rid of it. I found that sighting Polaris roughly centred through the empty slot gets me close enough and if doing photography I just do a drift align.

I believe Telescope Service have an illuminated one that may fit that mount though, so you could check with them.

Trev

Fintan,

There is a built in polar alignment routine in the CG5 which is plenty good enough for goto. I agree with Trevor, the polar alignment scope is a right pain to use.

Heres how it works.

1. Polar align as best as your eye can see, i.e. centre polaris in the hole where the polar axis goes.

2. Do a three star alignment.
3. Activate the polar align routine (think it is utilities -> polar align)
4. The scope slews to where it thinks polaris should be.
5. You now centre polaris in the eyepiece by ADJUSTING THE altitude and azimuth (up, down, left right) knobs on the CG5. DO NOT touch the hand control or move the scope in its RA and DEC axis.
6. Press Enter, you are now polar aligned with good enough accuracy for goto.
7. The downside of all this is the polar alignment routine loses your initial 3 star alignment so you must 3 star align again.

If you really wanna be sure you have a faint fuzzy dead centre. Use the 'Precise goto' feature. This works as follows.

Select precise goto on your handset (consult the manual). Choose your target. The mount then searches for the nearest bright star. Choose the star by pressing enter. The scope slews to this star. Centre the star in the eyepiece with the hand controller this time. Press Enter. The scope now slew the rest of the way to the object and places it dead centre. I found this works VERY well.

Couple of tips. Get your latitude and longitude right and precise. You can get very accurate co-ordinates from goole earth or maporama or any of those mapping websites.

Get the time right to the second. Buy one of those cheap radio controlled clocks from argos, they are dead cheap <20euro and give you the time accurate to 1/25 second. Every astronomer should have one!

Don;t forget to select daylight savings time when you enter the time and of course remember the celestron date format is american i.e. MM/DD/YYYY.

In short don't bother with the polar alignment scope The above is still a bit of a pain, but it's a lot less of a pain than using a PAS!