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Ledge1962

Polar alignment in the Southern Hemisphere

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Hi all. I am getting into Astrnomy but are faced with a couple of prblems due to location. Being in the Manawatu NZ, I am in the Southern Hemisphere, so we do not have a true South Star and as I do not have a Goto mount, just a Meade 2120B on a celestial wedge, I am interested to see how others (if any) in this hemisphere did their alignment without the computer.

I made my first mistake of polar aligning the mount using magnetic south so tracking with the Meade 2120B was (not surprisingly) unsuccessful. Once I realise my mistake, using the magnetic variation and a couple of hours of lining up with the compass has it close, but there is room for improvement before I put a camera on it. I did use Stellarium to print out a copy of the Southern Cross with the Celestial Pole on it and then got a piece of clear perspex and drilled the holes in it to match the stars. I can hold the Perspex up so the holes line up with the stars, and it gives an accurate location visually, now I just need to find a way to get the scope matching it.

Any hints (apart from buying a goto mount as they are expensive in NZ) would be appreciated.

Cheers

G

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Thank you for taking the time to respond. I will try both options as I am keen to put the 6D on the scope and see what transpires. Your time is appreciated.

 

 

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G'day Ledge.

To find a pretty accurate alignment you'll need to find solar culmination at your location using https://www.suncalc.org/#/-40.3643,175.6437,7/2018.01.30/13:31/1/0

Drag the red balloon to your scope spot and press the >I< button to set the program to your time and date. The time you're looking for is the "culmination".

Set a gnomon up, a stake or pole (use a spirit level to make sure it's straight up). At solar culmination time, the pole will cast a shadow exactly North/South, easy.

For dec, try an inclinometre on your phone or angle tool to set the altitude to your latitude. All that remains is to try the PhD2 alignment or drift align as noted above.

 

 

 

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Hi Ledge from across the ditch

I do not bother with polar aligning

With my EQ5 mount, using a compass, as you have discovered, allow for magnetic variation, which is 10deg east where I am

North leg of EQ5 mount has to point south as well

Then do a 2 star alignment

This time of year I use Sirius and Canopus

You should be 99.9% aligned

Draw a line through the Southern Cross, and through the 2 pointers to the Southern Cross, and where they intersect, is the South Celestial Pole

John

 

 

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If your budget can stretch, you could also consider Polemaster. There is a video on YouTube that shows how to use it for a Southern Hemisphere PA.

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Thanks to all for the great responses. I am really surprised to get so many and such informative ideas. I am just waiting for the weather to clear (if ever) and will put these suggestions into practise.

Cheers all.

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Ledge

Was over in Auckland on the weekend for family function

Saturday night, bucketed down

Thursday and Friday night was not too bad

Which part od NZ are u

John

 

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Hi John,

I used to live in Auckland, but moved to Marton about 2 years ago. The sky is certainly clearer here, but the weather is not very accommodating. I had to build a deck around the scope stand so I didnt keep sinking into the mud :)

Are you over from Aussie?

 

 

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Hello, 

If you have a camera and a laptop, you can use my PhotoPolarAlign method described here, it's been tested in Southern Hemisphere and can give Polar Alignment accurate to a few arcminutes  in about 15 minutes.

 

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Do you have to have a motorised mount to use it? I have a Meade 2120B and it only has a simple base tracking motor.

 

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On ‎22‎/‎05‎/‎2018 at 14:42, Ledge1962 said:

Hi John,

I used to live in Auckland, but moved to Marton about 2 years ago. The sky is certainly clearer here, but the weather is not very accommodating. I had to build a deck around the scope stand so I didnt keep sinking into the mud :)

Are you over from Aussie?

 

 

Live northern end of the Goldcoast, about 10 minutes inland from Movie world

Last weekend we had a day/night workshop with my astronomy club

During the day viewing and imaging our SOL

Was not much to see, as last couple of months has not been any sunspot activity

A small flare around 2pm

Had a BBQ dinner, and viewing and imaging in the evening

If you make it across the ditch, drop in to club meet

We meet Saturday night closest to full moon

Just purchased the new SynScan Wi-Fi adaptor

Works good

Found a couple of bugs in it though

John 

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Thanks John, I appreciate the invite. I don't think I will bring the scope though, the scope weighs 46lbs and the mount is about 55ton. It is a steel girder welded to 1/2" inch steel plate and dyna bolted into a small concrete pad. Awesome for stopping vibration, but Air NZ may complain if i took it in as carry on baggage.

I have been considering getting a 14-in Truss Dob (orion), what are your thoughts on the DOBs vs the OLD SCT's? My one is the Meade 2120B 10" on a EQ plate and has the old motor drive. It was made in the mid 90s i believe.

Hope all is well in Oz

 

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Ledge

No need to bring scope

Club has several 10" collapsible loan Skywatcher dobs, as well Meade 90, LUNT solar scope

We doing presentation for 180 grade 5 students at local primary school on the 19th

My contact details are on club website

Cheers

John

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Thanks John,

I am impressed with your hospitality towards new members. You are one of the reason these forums are so successful! Good luck with the 180 students, I really wish I was with them.

Thanks for your welcome onto this site, I feel more confident dealing with others now.

regards

George

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George

Why belonging to a club is so rewarding

Get a lot of satisfaction working with our youth of today

Also have over a dozen scout groups we involved in as well, and do Space Badge for Joey's

Have attached copy of criteria for Joey's Space Badge

Cheers

John

 

Space Badge.docx

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