Hello from Newmarket, Suffolk!

[xtreemchaos]

hi mate and welcome from charl in south wales.

[Seraph_69]

Hi again Steve,

The "why" is easy ..    for an equatorial mount to 'track' correctly, it must be aligned to celestial north.  Think in terms of "you ain't gonna draw a perfect circle without knowing where the centre is". 

So..  the nearest thing in the sky to celestial north that is easily observed, is Polaris.  The trouble is, Polaris ISN'T at celestial north.  But like all the other stars, it 'appears' to circle celestial north.  We know how long it takes Polaris to circle cn and from observations we know when it begins each 'orbit' at the 12 o/clock position. So, from any given point on Earth, at any given point in time, it is possible to 'calculate' where Polaris should appear in it's 'orbit' of celestial north.  Armed with that information, we then know where clestial north must be (as long as we can see Polaris!).  Once you have (perfectly) aligned your equatorial mount with celestial north, you can 'track' objects with your mount using only ONE axis of movement.  Always assuming the mount is on a perfectly level tripod or pier, that you know your exact location and the correct time etc etc.     The calculation part can be done several ways:  the traditional method (dating from before the digital age!) is using the setting circles fitted to your mount - think of them a as you would a slide rule, or a more modern approach is to use software instead.  Simples.

Hi Paul,

Thanks for taking the time to write up that explanation. I think this bit: "it is possible to 'calculate' where Polaris should appear in it's 'orbit' of celestial north.  Armed with that information, we then know where clestial north must be" is what helped me the most.

TBH, I understand why we performed the polar alignment, I confused myself by over-complicating some wording in one of Dion's videos over at Astronomy Shed, where he talked about rough alignment and said SOMETHING like:

"You can have Polaris anywhere in that circle and it'll be OK for rough tracking" - don't quote me on that! 

But either way it confused me as I thought 'well how the hell does rotating the RA change [removed word] all? Seeing as you dont actually change the alignment of the mount until you use alt/az knobs.

And then that lead me to think 'so how does this hour angle of Polaris thingy come into it?'

...now I understand that you need to correctly rotate the RA to find where Polaris truly is in it's orbit at the time of looking, in order for you to be able to then adjust alt/az to plop Polaris in it's circle - but only, and ONLY when you have the RA reticle/axis rotated to match the correct hour angle of Polaris, will this 'then move Polaris into it's small circle on the reticle, and you're basically sorted' actually send your crosshair off in the correct direction to be right over the NCP...PHEW!!   

Have I got this correct? This is my understanding anyway! My point was that it is difficult to understand exactly what I'm doing, when the thing I'm truly trying to align my crosshair to is invisible! i.e. How do I know I'm adjusting the alt/az / sending that crosshair off in the correct direction to actually put it over the NCP.

ANYWAY   Thanks very much for the reply - appreciate it 

[Seraph_69]

Hi Steve,

I'm from Newmarket and I also live next to the Cambridgeshire border (Granby Street).

I got my first scope (SkyWatcher 130P) just a few days ago. I'm still waiting for the sky to clear up to get started on it (hopefully this Thursday if the weather forecast is right).

I'm still trying to figure out a good place to setup the telescope here in Newmarket. I was thinking about going to the Gallops.

Did I say I also got a 2 year old son? :-)

Hope we will have a chance to meet.

Cheers,

Filipe

Hi Filipe,

Indeed, I hear the weather is indeed supposed to be clear for tonight. Such a shame that the Institute of Astronomy (in Cambridge) open evenings are every other WEDNESDAY, starting yesterday, as we didn't get to do any observing 

And unlike yourself, my scope hasn't arrived yet   

Myself and my gf are actually moving soon(ish), not too far away, but luckily for me, the back garden is huge and I should be able to set up at the house! 

I don't actually know Newmarket very well, it is my gf who has been living there a long time, I have only recently started residing there 

I am very keen to meet up and get to know other local amateur astronomers, just starting out like myself! Unfortunately I am going out tonight, otherwise I would love to join you for your first light!!

Maybe another time soon, whilst we are still in Newmarket?

Either way, let me know how it goes tonight - my fingers are crossed for clear skies for you!!   

[Chris]

Hi Steve, welcome to SGL from Chris, a bit further down the A14 in Ipswich. 

[Seraph_69]

Hi Steve, welcome to SGL from Chris, a bit further down the A14 in Ipswich. 

Hi Chris - was there the other week to collect my HEQ5 from a seller on AstroBuySell - UK. Really small world this is turning out to be