Astro-Physics 160 EDF Refractor
Feb. 5th 2007 Scottsdale,
The conditions of the sky right after sunset were textbook perfect. Not a cloud
to be seen anywhere and only a slight warm breeze. After the coldest January in
40 years here in Southern Arizona, we finally broke through to a near record
breaking daytime high of 83 degrees F! The sky was crystal clear with very
little Phoenix smog typical in the winter months. After waiting over 7 years for
this scope the curse (cloudy weather after buying new astronomy gear), must have
gotten tired of waiting and just went home.
I have the scope mounted on a relatively cheap Orion Atlas EQ-G goto mount. The
AP weighs in at 27lbs. Add the weight of rings, diagonal and 31mm Nagler and it
is probably up around 35lbs. The mount is rated for 40lbs, so it should be
fine… Theoretically… At least for visual work… I hope…
I didn’t bother with accurate polar alignment and just roughly pointed the
mount North with the Latitude setting at 33 degrees. Polaris is blocked from my
back yard, so only a very approximate polar alignment was going to happen
tonight. Anyway, tonight I wanted to see what the optics could do and wasn’t
as interested in spending the time to get everything aligned for good tracking
or pointing. I also only roughly balanced the scope, leaving the motors
straining in some of the more awkward positions. The fact that the Atlas did as
well as it did tonight says something about this little $1500 mount that could.
My first target was the 1 star alignment star, Sirius. It wasn’t totally dark
yet and I found Sirius pretty easily in my 35mm Nagler (just over 2 degrees of
field). It looked white just like in my Lightbridge. The other stars in the
field focused to pin pricks, no coma, no collimation issues, no false color.
Nothing but 2 degrees of tiny points of light against my light polluted
background sky. This was the first time I had seen stars this sharply focused in
a telescope for years. My 10” LX200 never focused stars so small, nor my
125ETX or even my 12” Lightbridge.
There was an ever so slight fringing of purple color around Sirius that I also
see when viewing very bright stars with the Nagler in my Lightbridge, so I’m
pretty confident that it wasn’t coming from the 160, but from the Nagler. I
centered Sirius in the 31mm and then put in my 9mm TMB. Again big bright Sirius
with no discernable color besides clean white!
I then put the 31mm Nagler back in and slewed the scope to M42. After hunting
around just enjoying the pin point stars, I came upon my old and trusted friend
the Orion Nebula. I’d seen her through dozens of different telescopes over the
years. While the nebulosity wasn’t as striking or bright as the view through
my 12” Lightbridge, the sharpness and sure elegance of the stars around M42
provided a more pleasing view. Once I centered the trapezium I put in my 17mm
Stratus. Could I make out the E star at 70x? Maybe… The 160 begged for more
power. I skipped my 9mm and went straight for my 5mm LE Tak. 240x or 40x per
inch of aperture. I could for the first time clearly and easily see both E and
F. I looked into that eyepiece and was just in awe how clear it looked at this
power. I had never seen it look this good in any telescope… ever! Was this
really only a 6 inch scope? Had Roland somehow magically put an 18 inch
objective into a 6 inch tube? The 4 major stars of the trapezium were tiny
bright circles and the fainter stars were still nearly points at 240x!
Next I slewed the scope over to the Pleiades, M45 almost at the zenith. With the
31mm Nagler back in I had to sit on the ground to get low enough to look through
The view was again the most amazing I had ever seen of this cluster in any
telescope… ever. The stars were rock steady, with the brighter stars shining a
brilliant bluish white, and the fainter stars tiny specks of light all the way
to the very edge of the 82 degree field. I couldn’t see any false color or
glare anywhere. I felt like I could almost reach out and touch them.
Saturn was still pretty low, but I just had to try. I slewed to scope to Saturn,
and after a few minutes of looking I centered the jewel of the solar system in
the 31 Nagler and jumped right for the big money with the 5mm Tak. Saturn was
right over the roof of my neighbor and each time their heater / AC unit kicked
on Saturn boiled. In moments of steady seeing the Cassini division was obvious,
but clearly Saturn had to wait until later.
After helping to put my girls to bed, I returned to the scope which was still
eagerly pointing upward almost calling out to me like a race horse ready to run.
I decided to investigate the trapezium even more closely now that I was alone
with the scope, it was totally dark, it was higher in the sky and the evening
air should be a bit more stead now that the sun had been down for a few hours. I
slewed the 160 back over to M42 and pushed right away to the 5mm LE Tak. The
stars now looked bloated and fuzzy. What happened? Did the objective dew over
(pretty much impossible tonight)? Did someone come along and switch scopes while
I was inside? I lowered the magnification with the 9mm and things looked better.
I apparently lost the spectacular seeing I was blessed with that first hour
after sunset. As I write this I’m trying to give the atmosphere a chance to
find its steady self again. I will then try again….