ATM 32" observing reports, close to the end

["at making" <atmaking@hotmail.com>]

Hi,

For the first time, I have observed in the 32  with a tuned astatic cell. A 
friend who know this kind of cell very well tune it in few minutes. I was 
not far but now is good. The difference in the view is simply amazing ! I 
was afraid to have some astigmatism but fortunately there is nothing visible 
while going from zenith to horizon. The last part to tune is the tracking 
but the first tests are a big promise. It could have been finished but a 
lack of time and our enthusiasm to share time at he eyepiece under a good 
sky as give us problem J

The scope is easy to setup, about 10 minutes. Currently the primary is 
transported in a separate box. The mirror box and rocker or on a trailer.  
The primary and top cage in a station wagon. Two people “drop” the mirror in 
the cell, remove wheels, put the truss, the cage, baffle system and it’s 
ready. First surprise, on 4 setup, twice the scope didn’t need to be 
collimate ! and and an other time a small collimation. I know try to always 
installed the truss at the same place and this way, it does not seem to 
require collimation. May be I will don’t need to have the remote electrical 
collimation system.

The place was a pass in south of france, at 4800 ft. Fun, we decided to go 
at this place at night, so the trip and setup was done during the night. The 
sky was great naked eye, with a very broad and full of detailed Cygnus area. 
As for many new scope, we spend  first observing session on classical bright 
object. We were not disappointed to say the least.

M27 was not the classical hourglass shape. It was full of thin details, and 
extension, only visible on heavy processed CCD images. The extension are 
like an “echo” of the classical shape.

The veil nebula was a AMAZING view ! the central part (between the two 
brightest arc) was like the brightest arc in a 20” ! You have to use high 
quality CCD shot to see as much details and in many case it’s more 
impressive at the eyepiece. The broadest part near 52 cygni remember me a 
all the ramifications of  rivers are branches of a tree. Complex, hard to 
describe. It was with the paracorr and nagler 20 mm eyepiece. Unforgettable.

M33, at low power (paracorr +20 mm nag), NGC604 got a distinct shape with a 
haze around it , and some  stars (with good seeing). I will use higher power 
and try to make some drawing next time as it will be at an even better dark 
site.

6543 was great. With good seeing, all classical details were visible. Green, 
with something like a dark brown/deep red faint line at is perimeter. The 
faint galaxy next to it was easy. Around cat’s eye, the haze was visible and 
something I never notice before, a reinforcement of this haze was visible, 
opposite to the direction of the galaxy if memory serves me.

M13 was big, fully resolved. The faint galaxy between M13 and ngc 6207 was 
easy to see and got a shape.

We also spend time on NGC253, 891, M15, Stephan’s quintet,

I can’t wait to have the tracking as it full capacity. It should have been 
already finished but when you begin to jump from an object to an other, it’s 
hard to stop 5 minutes J.

Strange things happen, during humid night, the graphite fabric I used to 
cover parts of the cage and focuser board, and in a smaller proportion, 
other parts of the cage are covered with humidity. The truss itself (also 
graphite tubing but made an other way) don’t seem to suffer to much of that 
problem. A good point, this graphite tubing is not cold during cold night so 
gloves are not necessary like for alu truss. Rigidity of the full structure 
seems to be excellent. Something I will need to modify a little is the size 
of the 3 pad that touch the ground, a little wider will be better for 
stability on “unstable” grass place.

Piano wire seems to be good. They are 2 mm in diameter and support a 44 kgs 
(around 97 lbs). Their “free part”  are not very long (around 20 mm) but 
seems to be enough. To use the scope as it full capacity, it’s good, when 
the collimation is finished, to aim the scope at zenith, move the primary by 
hand for few millimetres and aim the scope at horizon to let it take is 
position without any stress. Good point to, the meniscus seems to be very 
rigid. I even wondering if it could not have been put on a 18 points ! I 
know that sound an exaggeration but it’s not the case. The meniscus is 40 mm 
thick, but seems to have a stiffness close to what can give a 24” 40 mm 
thick, flat shape. I will speak about that with Luc Arnold soon. The shape 
seems to be a real bonus. If I’m not lazy, I might  make an even simpler 
cell (astatic with 18 points) one day to see how the glass react.

Sorry for the double mail for people whom are on atm and bigdob.

Frédéric Géa
http://astrosurf.com/altaz/index_e.htm