Subject: RAT NOTES - TEC 200 APO F9 - 09/06/04
From: t (Ratboy99)
Date: 9/7/2004 4:51 PM Eastern Daylight Time
Message-id:


Well, I've had the scope out a couple more times, now.

The most notable observations occurred last night.

I spent probably half an hour getting a model generated with the Gemini
system,
and after a half a dozen stars or so, it was pointing pretty well. I still
like
star-hopping, and the main reason I did the careful alignment was to get the
scope properly polar aligned. Once I had a proper polar alignment, I marked
the
ground with spray paint where the tripod legs need to be to be able to set it
up easily in the future.

After a while, most of my objects were still falling outside of a 105 x
Nagler
eyepiece, so I had to do a bit of searching each time. I will continue to
work
on the accuracy of the pointing models. Also, a fix is in the works with
Losmandy that will effectively double the torque from the motors, due out in
the next few weeks.

Beta Delphini:

The alignment was good enough to hold Beta Delphini in the FOV for extended
periods at high power. Beta Del is a tight .5 arcsec double with components
of
4.0 and 4.9; the fainter component lies generally north of the primary.

I popped in a 3mm Radian (600x), and sat down to watch.

It only took a few moments to split.

I was hoping just to get an "elongation", or perhaps if I was lucky a "peanut
shape", but this puppy split - not clean mind you, with black space between
the
components, but clearly into two Airy Disks, nonetheless, one brighter,
conjoined with a fainter one, and the PA was dead on (I waited until after to
check), it looked very much like a snowman at that extreme high power.

Wow!

I dropped down to a 4mm Radian (450x), and it was still split.

I dropped down to my 30x per in, which is what I stated earlier as my
theoretical value at which I can see all an objective has to show; and no
way,
I just couldn't do it.

So, now **that** theory is out the window, and I've got to go out again and
convince myself that the other two tight doubles (OS 403, .8 arcsec and 410,
.6
arcsec) were actually as cleanly split as I thought they were at that lower
magnification.

Logically, resolution is a matter of angular size: If I can split, 208 arcsec
(E Lyrae) naked eye, I should be able to split .5 arcsec (Beta Del), at 400x.
That is the logic, but, again, I suspect that image brightness has something
to
do with it, as well of course as the optics.

I am frequently limited with my other scopes to about 200x on Jupiter, which
would lend the idea that I am only resolving about 1 arcsec most of the time
with those scopes. I will be very interested to see Jupiter when it comes
around.

Speaking of which, I'm not much of a morning person, but if this kind of
performance keeps up, I may have to break down and drag my ass out of bed one
morning and have an early look at Saturn.

Anyway, I know that I am supposed to be irrationally exuberant after having
just acquired a new scope, but this is ridiculous. I've never seen an
instrument work so well for double stars, and I've looked through a few.

Regarding the focuser: I noticed that it was in an awkward position as I
observed Beta Del at 600x, so I thought I would loosen up the clamps and
rotate
it so I could reach the 10:1 knob easier. I loosened the focuser and rotated
it
about 100 degrees, loosened the collet holding the diagonal and rotated it to
where I could hold my eye comfortably, tightened it all up again, and there
was
Beta Del still centered in the eyepiece at 600x!

Sheesh! Looks like I'm going to be getting some less sleep.

I should at this point put in a word about cool down. I pulled the scope out
of
a 65 degree F room and set it up at 45 degrees F outside. I let it cool for
about 90 minutes. As I was observing out of focus star images at high power,
I
could still see evidence of the big glass cooling out of focus. But after two
hours it was ready to split the .5 arcsec double. Not bad, a couple hours
cool
down was pretty much what I was expecting.


NGC 6543 - PN - DRA - Cat's Eye Nebula - Well, let's have another Holy Cow!
It
looks like PN's are going to be right up this scope's alley as well. Very
bright, round (it looked quite round to me, but then I didn't pay as close
attention to "shape" as perhaps I should have), gray disk, with a distinct,
and
very sharp, pinpoint central star. This PN "blinks" for me when stared at
through the big glass, but it has just enough aperture to keep the nebulosity
present (in and out), with direct vision. Astounding. Looks like I'm going
to
be doing some more PN hunting in the near future - 106x

A couple more for fun:

M57 (of course) - Ring Nebula - PN - LYR- Wow, This is too fun! I noticed a
couple of faint stars, coming in and out of view, lying just outside the ring
(in addition to the Mag 13 one that I usually see), I am going to check later
and see what Mag they were. Nice bright image, it is not a bad aperture point
at all for bright DSO's, the contrast under dark skies is exceptional - 106x

M13 - Yup, that's M13 alright. I'd say aperture-wise the light grasp is well
beyond that of an 8" reflector, but I believe that my 10" Newt can go
fainter.
Not really the point with this one though, those stars in M13 are really,
really sharp - Beautiful - 106x


Being such a new telescope, I find that I am not spending as much time on
each
object as I would really like. I imagine the next few days will be spent
revisiting the above-mentioned objects again as my initial evaluations
continue.

Oh well, somebody's got to do it.

Pretty damned fun actually, and I guess that's what it is really all about
for
me.


rat
~( );
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You need to bring that 8" to my 9+ seeing skies in FL, you would go nuts with
views of the planets at 600x to 900x!!!

And with the super contrast that a 8" APO has, globs and other deepsky object
would make your jaw drop.

Chas P.