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Main
Date: 01 Aug 2006 04:41:14
From: MThomas
Subject: polar alignment
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I see that polaris is moving clockwise around my polar finder circle. Does
that mean it is aligned?
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Date: 01 Aug 2006 14:16:46
From: Chris L Peterson
Subject: Re: polar alignment
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On Tue, 01 Aug 2006 04:41:14 GMT, "MThomas" <mikeman_80@hotmail.com >
wrote:
>I see that polaris is moving clockwise around my polar finder circle. Does
>that mean it is aligned?
I guess it depends on how your scope inverts the image. Like all stars,
Polaris rotates counterclockwise around the pole. Does your polar scope
show this small circle?
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 01 Aug 2006 14:52:42
From: MThomas
Subject: Re: polar alignment
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"Chris L Peterson" <clp@alumni.caltech.edu > wrote in message
news:ocouc21ec9hkhokrg9j622es9uu9g29cqg@4ax.com...
> On Tue, 01 Aug 2006 04:41:14 GMT, "MThomas" <mikeman_80@hotmail.com>
> wrote:
>
>>I see that polaris is moving clockwise around my polar finder circle.
>>Does
>>that mean it is aligned?
>
> I guess it depends on how your scope inverts the image. Like all stars,
> Polaris rotates counterclockwise around the pole. Does your polar scope
> show this small circle?
Yes. The circa 1998 style CG-5.
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Date: 01 Aug 2006 15:01:59
From: Chris L Peterson
Subject: Re: polar alignment
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On Tue, 01 Aug 2006 14:52:42 GMT, "MThomas" <mikeman_80@hotmail.com >
wrote:
>> I guess it depends on how your scope inverts the image. Like all stars,
>> Polaris rotates counterclockwise around the pole. Does your polar scope
>> show this small circle?
>
>
>Yes. The circa 1998 style CG-5.
If you are watching long enough to see Polaris rotate significantly, and
it is staying on the circle, it should mean you have a good alignment.
Where you could go wrong would be if you were misaligned by the full
diameter of the circle. In that case, over a short time Polaris might
appear to be tracking correctly, but in the other direction. But an
offset this large would show up clearly in the other reference points on
the reticle, so I doubt you are seeing that.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 01 Aug 2006 16:15:22
From: MThomas
Subject: Re: polar alignment
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"Chris L Peterson" <clp@alumni.caltech.edu > wrote in message
news:ctquc2ha26rirnq7e83at0lgouao7e5nld@4ax.com...
> On Tue, 01 Aug 2006 14:52:42 GMT, "MThomas" <mikeman_80@hotmail.com>
> wrote:
>
>>> I guess it depends on how your scope inverts the image. Like all stars,
>>> Polaris rotates counterclockwise around the pole. Does your polar scope
>>> show this small circle?
>>
>>
>>Yes. The circa 1998 style CG-5.
>
> If you are watching long enough to see Polaris rotate significantly, and
> it is staying on the circle, it should mean you have a good alignment.
> Where you could go wrong would be if you were misaligned by the full
> diameter of the circle. In that case, over a short time Polaris might
> appear to be tracking correctly, but in the other direction. But an
> offset this large would show up clearly in the other reference points on
> the reticle, so I doubt you are seeing that.
>
I didn't do it long enought to see if it is really is traversing the circle.
Tonight
I'll make sure because I left the tripod standing. Within how many seconds
of arc
is considered a pretty good alignment? I believe the NCP is offset about
15". Is that right?
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Date: 01 Aug 2006 16:22:08
From: Chris L Peterson
Subject: Re: polar alignment
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On Tue, 01 Aug 2006 16:15:22 GMT, "MThomas" <mikeman_80@hotmail.com >
wrote:
>I didn't do it long enought to see if it is really is traversing the circle.
>Tonight
>I'll make sure because I left the tripod standing. Within how many seconds
>of arc
>is considered a pretty good alignment? I believe the NCP is offset about
>15". Is that right?
When it comes to polar alignment, "good" is relative. What is your
intent? For visual use, a few degrees is fine. For imaging, it depends
on how long your individual exposures will be. An alignment to within a
few arcminutes of the refracted pole is fine for nearly all guided
imaging. Getting that close with a polar alignment scope is pretty
difficult, though.
_________________________________________________
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
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Date: 01 Aug 2006 16:30:53
From: MThomas
Subject: Re: polar alignment
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"Chris L Peterson" <clp@alumni.caltech.edu > wrote in message
news:pnvuc2tvnatv9l0vr016lsul57eg43g00r@4ax.com...
> On Tue, 01 Aug 2006 16:15:22 GMT, "MThomas" <mikeman_80@hotmail.com>
> wrote:
>
>>I didn't do it long enought to see if it is really is traversing the
>>circle.
>>Tonight
>>I'll make sure because I left the tripod standing. Within how many
>>seconds
>>of arc
>>is considered a pretty good alignment? I believe the NCP is offset about
>>15". Is that right?
>
> When it comes to polar alignment, "good" is relative. What is your
> intent? For visual use, a few degrees is fine. For imaging, it depends
> on how long your individual exposures will be. An alignment to within a
> few arcminutes of the refracted pole is fine for nearly all guided
> imaging. Getting that close with a polar alignment scope is pretty
> difficult, though.
>
NCP is 45 arcminutes from polaris.(3/4 of a degree) Larger than the angular
diameter of the moon!
If however polaris is tracking faily well around the circle then I have to
conclude that my alignment is quite accurate.
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Date: 01 Aug 2006 19:06:41
From: Iordani
Subject: Re: polar alignment
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MThomas wrote:
> NCP is 45 arcminutes from polaris.(3/4 of a degree) Larger than the
> angular diameter of the moon!
>
> If however polaris is tracking faily well around the circle then I have to
> conclude that my alignment is quite accurate.
You could try a small program called PolarFinder by Jason Dale. Google will
find it for you.
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Date: 01 Aug 2006 17:57:56
From: MThomas
Subject: Re: polar alignment
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"Iordani" <somewhere@earth.net > wrote in message
news:4j9g11F6ulb4U1@individual.net...
> MThomas wrote:
>
>
>> NCP is 45 arcminutes from polaris.(3/4 of a degree) Larger than the
>> angular diameter of the moon!
>>
>> If however polaris is tracking faily well around the circle then I have
>> to
>> conclude that my alignment is quite accurate.
>
> You could try a small program called PolarFinder by Jason Dale. Google
> will
> find it for you.
Totally useless comment.
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Date: 01 Aug 2006 20:18:26
From: Iordani
Subject: Re: polar alignment
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MThomas wrote:
> Totally useless comment.
I quite agree.
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Date: 01 Aug 2006 20:32:59
From: MThomas
Subject: Re: polar alignment
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"Iordani" <somewhere@earth.net > wrote in message
news:4j9k7hF7092dU1@individual.net...
> MThomas wrote:
>
>> Totally useless comment.
>
> I quite agree.
You're another useless freak sticking their nose in where it don't belong.
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Date: 01 Aug 2006 03:36:44
From:
Subject: Re: polar alignment
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oriel36 wrote:
> MThomas wrote:
> > I see that polaris is moving clockwise around my polar finder circle. Does
> > that mean it is aligned?
>
> I am sure that very distant star moves clockwise for you and all the
> others here but [rest of self important claptrap snipped]
Give it a rest you tedious little man.
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Date: 01 Aug 2006 03:28:17
From: oriel36
Subject: Re: polar alignment
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MThomas wrote:
> I see that polaris is moving clockwise around my polar finder circle. Does
> that mean it is aligned?
I am sure that very distant star moves clockwise for you and all the
others here but there once was a time when men took notice of what
actually was moving and how to resolve observed motion by using an
orbitally moving Earth.
You are mere photographers who spend your time negating the forground
motions of the planets and especially the one you are standing on and
look out at a celestial sphere peep show based on a cycle of 3 years
of 365 days and 1 year of 366 days.
The once great astronomical tradition that stretches back to remote
antiquity is gone from the planet,my God,the methods and insights of so
many civilisations including the great Western tradition is lost to
airheads who complain of cloud cover and light pollution as something
contrary to astronomy.The great intuitive faculties of humanity which
once dominated astronomical methods and insights no longer shine
,replaced by aperature size and gizmos.
You know no better and that is fine but that not one single person here
has a feel for the basic astronomical motions of the Earth can only
translate into a very difficult period ahead for humanity and future
generations.The loss of genius to an empirical imposter which makes
things linguitically complicated without adding anything productive in
astronomical matters is perhaps the greatest loss our race has known.
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Date: 01 Aug 2006 21:47:00
From: William Hamblen
Subject: Re: polar alignment
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On 2006-08-01, MThomas <mikeman_80@hotmail.com > wrote:
> I see that polaris is moving clockwise around my polar finder circle. Does
> that mean it is aligned?
Only when the sun rises in the west.
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Date: 02 Aug 2006 05:17:29
From: oriel36
Subject: Re: polar alignment
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grey.1734@googlemail.com wrote:
> oriel36 wrote:
> > MThomas wrote:
> > > I see that polaris is moving clockwise around my polar finder circle. Does
> > > that mean it is aligned?
> >
> > I am sure that very distant star moves clockwise for you and all the
> > others here but [rest of self important claptrap snipped]
>
> Give it a rest you tedious little man.
Tedious and troublesome were the words used by John Harrison in
describing the celestial sphere guys who remain dominant into this
era .You are dull and dreary descendents of the people who made life
for Harrison miserable and his method based on axial rotation at 4
minutes for each degree and 15 degrees for each hour of axial rotation
-
"Now, in the former part of this book, I have treated about matters
pertaining to the strictness of measuring time; and have shewn the
deficiencies of such means as Mr. Graham had taken or made use of for
that purpose; and I have also treated of the improper, troublesome,
erroneous - tedious method, which the professors at Cambridge and
Oxford would have to be for the longitude at sea:"
" But indeed, had I continued under the hands of the rude
commissioners, this completion, or great accomplishment, neither
would, nor could, ever have been obtained; but however, providence
otherwise ordered the matter, and I can now boldly say, that if the
provision for the heat and cold could properly be in the balance
itself, as it is in the pendulum, the watch [or my longitude
time-keeper] would then perform to a few seconds in a year, yea, to
such perfection now are imaginary impossibilities conquered; so the
priests at Cambridge and Oxford, &c. may cease their pursuit in the
longitude affair, and as otherwise then to occupy their time." John
Harrison.
Anti-heroes of our race,anything good was assimilated and eventually
turned into a perversion,even Harrison's accurate clock and the
Equation of Time noon correction by which he gauged its accuracy.
Go ahead and look out on your celestial sphere tonight,it will not be
the same cosmos that Harrison,Copernicus,Kepler,Ptolemy and Galieo
looked out on.The merry-go-round of a celestial sphere was fine as a
convenience until they discovered a way to justify its existence using
the Earth's axial and orbital motions,not for any astronomical purposes
but to gauge terrestial longitudes.What a horrible thing to do.
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