Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_lunar_landings.thumb.jpg.b50378d0845690d8a03305a49923eb40.jpg

hubble space telescope

when i do polar alignment?

Recommended Posts

hello everyone!

a quick and maybe a weird questionūüėÖ

when i do polar alignment? when the mount (i have eq6r pro) is turn on or off? if off - i do the alignment, turn on the mount, put my date and time, do the star alignment, and thats it? (this is the way i've done all my nights...) if on - what i do?ūüėÖ

and also what i do if i do the polar alignment with sharp cap or with polemaster? when the mount is on or off??

thank you very much!!!

  • Like 1

Share this post


Link to post
Share on other sites

You've got it right - polar alignment sets an EQ mount up to be used accurately, and is a physical alignment achieved by physically moving the RA axis (using the latitude and elevation bolts). This is done first and there is no need to have the mount switched on.

Star alignment is the setting up of the goto 'computer' (traditionally the handset in an out-of-the-box goto mount), rotating the mount around its RA and Dec axes to allow the computer to align its internal database of sky objects with where in the sky it needs to point the telescope to see those objects.

The goto computer assumes accurate polar alignment, and so star alignment always needs to be done second. 

Ady

(I hope this makes sense, I've redrafted it a couple of times for clarity, but in my experience this can sometimes make it less clear ūüėā)¬†

  • Like 1

Share this post


Link to post
Share on other sites

This is basically correct, but in some circumstances it can help to switch on the mount.

I could never get on with the polarscope and so bought a polemaster (Sharpcap basically does the same thing now, but is a lot cheaper!). Part of the process for this involves rotating the RA axis and then returning it to the start position. The computer then works out where the centre of the circle is and where it should be. It then directs you to alter the altaz bolts to get it there. Although this can be done manually, it is easier using EQMOD (as the laptop is connected anyway) and its "park to home" option.

  • Like 2

Share this post


Link to post
Share on other sites

When I first started polar alignment I found it useful to do it with the mount switched on and tracking. This was just because in early days it used to take me quite a while to get it done as I was not altogether sure I was doing it correctly.

Also I found it reassuring that I had correctly aligned after polar alignment to leave mount as it was and leave it tracking for 30 mins or so and check that Polaris was still in the same place exactly. This was just to convince myself I was doing things correctly and obviously I now get straight to business¬†ūüôā¬†

Share this post


Link to post
Share on other sites

teoria_del_big_bang - its sound very clever this method!

and thank you everyone! really appreciate it!

so its sound that it is not really matter if the mount is on or off (as long i dont move the RA and DEC manually). and with the polemaster - that the mount must to stay in "on" because i move the telescope in the RA axis?

  • Like 1

Share this post


Link to post
Share on other sites

It doesn't HAVE to stay on, as long as you can return the mount to "home position" after the rotations the method needs (releasing the clutch and moving it manually). But to use these methods, you need to be hooked up to the computer anyway,  so it makes sense (I reckon) to use that to do the rotations automatically.

  • Like 1

Share this post


Link to post
Share on other sites

it is sound better that the mount will stay on (i also saw a video that the guy there use polemaster and his mount is on)

and when you say home position, what is that means? i know the the scope in home position aimed to polaris and the mount - the counterweight is facing down...

thank you!!!

  • Like 1

Share this post


Link to post
Share on other sites

Yes. Home position is with the counterweight bar facing downwards. The position of the other axis is irrelevant. Remember,  polar alignment is only making the RA axis parallel to the earth's axis. You can align the mount with no telescope on it at all.

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

√ó
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.