star adventurer

[hubble space telescope]

hello everyone

just bought the star adventurer and i have one question that i didnt find the answer to it in the internet.

so:

when you remove the cover of the polar scope, you have the polar scope and couple of circles with numbers on them. what are these circules and the numbers? do i need them to the astrophotography? can i just spin them? (because i had and i have no idea what they are doing...).

thank you very much!

[knobby]

Align the numbers like a clock but with 0 at the top, then use the sam app and align Polaris with the little grey dot.

Polaris is not quite the celestial pole, it rotates and the app will show you where it should be at any given time.

The more accurately you align, the longer you can track without trailing.

 

[hubble space telescope]

i still dont understand for what they are good? i have an app on my phone that tell me the position of every star on the sky: SkyView.

so i can move and adjust the star adventurer according to the app. so why i need the circles?

thanks! 

[Davey-T]

Just for decoration really, you can use the Dec numbers to set your location if you've got the wedge.

Dave

[hubble space telescope]

dec numbers? you mean my latitude?

but what are the main purpose of these circles? they are helping me to find polaris Based on the numbers? how does it work, even if it will not helping me, i just want to understand it... 

thanks!!

[pipnina]

The diagrams help you get polaris into exactly the right spot, after aligning the mount roughly so that polaris can be seen in through the polar scope.

Polaris sits on the ring of the circle, the time of night and the time of year determine where on the circle it should be. I use stellarium to see whereabouts polaris should be on the circle just before setting it up, and tend to get it close enough. I can usually manage 2 minute exposures on my 105mm lens (some get that time with a 300mm lens, but that takes very accurate alignment and I don't have the patience).

Over all, I think the diagrams are very useful

[Davey-T]

25 minutes ago, hubble space telescope said:

dec numbers? you mean my latitude?

but what are the main purpose of these circles? they are helping me to find polaris Based on the numbers? how does it work, even if it will not helping me, i just want to understand it... 

thanks!!

Yes, if you've got the wedge set your latitude on the scale to give you a starting point.

In theory you can use them to find Polaris but as mentioned it's much simpler to use one of the many Polar Apps to set it in the right spot.

There's probably something on Y'Tube explaining the process of using setting circles or maybe on Astronomy Shed.

Dave

[hubble space telescope]

so you put your local time/hour/day etc... on these circles and then you look on the polar scope and it should give you where polaris should be?

[Davey-T]

Here you go, a bit about it here.

Dave

http://www.astronomyshed.co.uk/forum/viewtopic.php?f=19&t=514

[hubble space telescope]

ok

thank you for all your help!

[JamesF]

Since I'm reading up on stuff relating to the SA at the moment, I just thought I'd add:

Polaris isn't exactly on the north celestial pole.  It's close, but not quite.  That means that as the Earth rotates Polaris appears to circle the NCP.  The reticle represents that with the circles showing the path of Polaris about the NCP (the cross in the middle).  The app tells you, based on your location and the current time, whereabouts on that path Polaris should be at that moment, so if you adjust the mount to put Polaris in that position then the cross (which is aligned with the RA axis of the mount) should coincide with the NCP and the RA axis will then be aligned with the Earth's own axis of rotation.

James

[hubble space telescope]

ok!

thank you very much for your help!