10-inch LX-200 - Finding Sigma Octantis

Shano592 (Shane) · #1 24-11-2010, 09:26 AM

Well, the new scope and accessories arrived over the weekend. I must say, I'm glad I didn't go for the 12-inch, as the 10 is inside my ability to lift, but not by a whole lot.

One thing that I am having trouble with ... in the calibration area, the telescope obviously tries to find the South Celestial Pole, being in the Southern Hemisphere. It asks you to centre on Sigma Octantis, which appears to be the closest star to the SCP.

My problem is, that Octans is a very unremarkable constellation, and I couldn't tell Sigma Octantis from any of its sisters.

So, to those who have done it, how do I determine which is Sigma?

BTW, the scope is staggeringly fun. It can align itself (as one option), and last night I had it hitting Jupiter (and 4 moons), the Tarantula Nebula, and 47 Tucanae, right to the centre of the 10mm EP.

Woolies has 8x C-cell Duracells for $13.50. So far I have gotten about 5 hours of runtime out of them. A lot more than everyone has been saying I would.

jenchris (Jennifer) · #2 24-11-2010, 10:10 AM

Buy a Gel Battery from Battery world - $38 for a brick sized one - which is rechargeable and will last you all weekend.
Remember - if the OTA is balanced, the motors won't draw much power.
Remember centre pole is positive - don't get them the wrong way round and fry your electronics (Meade 'forget' to put in a diode to stop that happening - thereby making even more profit)

GrampianStars (Rob) · #3 24-11-2010, 11:37 AM

Get a power supply if your near 240vac
http://www.jaycar.com.au/productView...T&SUBCATID=381
Oh! Polar Aligning
http://www.southern-astro.com.au/php...ralignment.php

jenchris (Jennifer) · #4 24-11-2010, 01:33 PM

AC adapters are something to avoid if you can, as they can easily throw up spikes which are not tolerated by scope electronics.
If you don't go with a gel battery, get a jump start machine from BCF or Super Cheap - they also have a cig lighter socket so you can plug in whatever you like!

mozzie (Peter) · #5 24-11-2010, 04:59 PM

Quote:

Originally Posted by Shano592

Well, the new scope and accessories arrived over the weekend. I must say, I'm glad I didn't go for the 12-inch, as the 10 is inside my ability to lift, but not by a whole lot.

One thing that I am having trouble with ... in the calibration area, the telescope obviously tries to find the South Celestial Pole, being in the Southern Hemisphere. It asks you to centre on Sigma Octantis, which appears to be the closest star to the SCP.

My problem is, that Octans is a very unremarkable constellation, and I couldn't tell Sigma Octantis from any of its sisters.

So, to those who have done it, how do I determine which is Sigma?

BTW, the scope is staggeringly fun. It can align itself (as one option), and last night I had it hitting Jupiter (and 4 moons), the Tarantula Nebula, and 47 Tucanae, right to the centre of the 10mm EP.

Woolies has 8x C-cell Duracells for $13.50. So far I have gotten about 5 hours of runtime out of them. A lot more than everyone has been saying I would.

hi shane
ive just calibrated the sensors on my meade scope.and i also did this on my lx90.
ok i cant see scp ive trees to the south so this is what ive done.
align your scope as usual go to a bright star in the south acernar,canopus etc,then if needed sync to centre know a star in the south is in the centre of eyepiece.put high precision on, then enter the s.a.o no: for scp it will then take you to another close by star centre it then it goes to scp. i then put my setting circle dec:to 0 r.a:to 0....
you then goto calibrate sensors it does an alignment again then goes to scp you can then see how far out the ra & dec are just put them to 0 again and your scope is that close to scp its not funny......
when i align my scope know the to stars are in the eyepiece or just out within 2 deg on the telrad i hope this helps

Shano592 (Shane) · #6 24-11-2010, 05:55 PM

Thanks for all replies.

Jenny, yes I have a jump starter, and the Bintel DC lead arrived today (it has the fuse in it). So, now power isn't an issue. Batteries have been removed, so I don't forget later.

Thanks for the links, Rob. I had a brief look, and I'll try to study it more when I can clear my head a little.

Mozzie, part of that post lost me! I can do the alignment, and I set the bore sight before nightfall, on one of the cooling towers from the power station. But after syncing a bright star, things turn Dutch for me. Perhaps I need to RTFM a bit more...

Also, what is the SAO for the scp? I wasn't aware that it had one.

Having re-read it, most of it makes sense. Just the points above are catching me out.

Thanks so far to all.

mozzie (Peter) · #7 24-11-2010, 06:29 PM

hi shane
sigma octane sao: 258857 this is the star youre after

AndrewJ · #8 24-11-2010, 07:23 PM

Gday Shane

All Mozzie is saying is do a std 2 star align manually.
Then goto Sig Oct ( As its an LX200, you can use HD 177482 as an identifier as well )
The scope will go to a location pretty close to Sig oct.
Centre it and mark your setting circles on this point.
When you then do the calibrate sensors,
the scope will use its level and North sensors
to "try" and point at Sig Oct. ( It will be way off )
All you then do ( without looking in the EP or finder ) is manually slew the scope till the markers on the setting circles line up again,
Sig Oct should be in the Eyepiece, and if not, easily in the finder.
Just centre and hit enter and its done.

Now the caveat
The calibrate sensor data is ONLY used to get you close to the first align star,
after that, its ignored.
If you can manually see/identify a few bright stars, you can just do a manual 2 star align and totally bypass the auto aligning dance.
Saves heaps of time and wear on the gears.

Andrew

Shano592 (Shane) · #9 01-12-2010, 11:03 AM

Wow, that caveat is interesting.

I do know enough stars, separated by at least 60 degrees of sky, that I could manually align 2 stars. Perhaps then, that is the way to go.

The joyous Sydney summer rain has denied me the chance to calibrate thus far, so it looks like I will try the 2-star, if the clouds ever leave us.

Many thanks, once again.

jenchris (Jennifer) · #10 01-12-2010, 12:33 PM

How do you do that without a cross hair reticle?

marki · #11 01-12-2010, 01:26 PM

I do the same as Mozzie. Make sure you have a good look through the finderscope to see the 4 stars of the octans asterism and when you look in the EP you should see 3 stars that make up a number "7" shape (two very faint and one brighter). The brightest one is sigma octanes.

Mark

mozzie (Peter) · #12 01-12-2010, 02:03 PM

Quote:

Originally Posted by marki

I do the same as Mozzie. Make sure you have a good look through the finderscope to see the 4 stars of the octans asterism and when you look in the EP you should see 3 stars that make up a number "7" shape (two very faint and one brighter). The brightest one is sigma octanes.

Mark

hi mark
its easy to have the scope go there then set the setting circles.!! as i was saying to shane ive never seen sigma to many trees but once ive calibrated sensor the alignment stars are in the eyepiece or just out..
thats close enough for me !!!!!