Alrighty, the presence of clear sky had me test driving my latest aquisition, the 12" truss dob. I'm slowly getting the hang of it.
The 12" dob has 4, count 'em 4 fans on the mirror cell but I don't have an AC power supply to run em with. So cooling naturally takes a hella long time. Before observing, I had to place paper shims between the mirror edge and a couple of the silicon blobs supporting it as I found that collimation was slipping as I moved the scope in altitude. Luckily my plan worked and collimation barely moves during the course of the night. As for the secondary, I *think* its collimated - I WANT CATSEYES!!! The scope I think has a little bit of astigmatism, not sure if that is a byproduct of thermals around the mirror, seeing, or maybe the secondary is pinched (it appears to be held in a sleeve similar to those of the GSO dobs).
Scope: 12" F4.6 truss dob and it's 50mm finder (or mini refractor)
Time: 11pm-2:30am
Seeing: 6/10
Transparency: 4/5
Dew: No
Temp: 10ºC
Started off with
M42. Very detailed at 108x, 6 trap stars easy at only 83x. The smaller nebula
M43 directly to the north actually takes on the shape that is visible in photos.
Homunculus Nebula
The brighter loop is noticably uneven, with a tiny star visible tucked in right near Eta Carinae. One of the lateral jets was easy at mags up to 353x but any higher and the nebula grows too dim to make much of it. Best views are obtained with mags in the high 200's to low 300's.
Running CHicken Nebula
Easy, obvious and very large glow surrounding a chain of stars just SE of Lambda Centauri. At 64x with the UHC filter, the nebula took up the entire central half of the FOV.
GUM 39
Located NW of the running chicken, this is a fainter object, appearing as a large rectangular glow, barely discernable from the background sky.
Ced 122
Just southeast of the Coalsack lies this large, faint nebula. Brightest portions surround an imbedded dark nebula and appeared as a faint haze at 64x with the UHC.
At this point I felt that something was 'not right' with the scopes collimation, so I grabbed a flashlight, allen key and toyed with the secondary. The result - noticable improvement!
Next I began scouring the
Eta Carinae region - with the 50mm finder. The finder actually has a 1.25" diagonal with interchangable eyepieces, meaning I can put my 6, 7.5, 9, 12, 15, 18 and 30mm plossls to good use
The finder gave a lovely star studded field with Eta Carinae and NGC 3532 in the same FOV with the 18mm plossl. Through the main scope, Eta Carinae was obviously breathtaking, just that huge expanse and those dark clouds within it plus several clusters make it a real treat!
Saturn
Holy crap - at one stage I could hold 272x with superb clarity!
The crepe ring was too obvious, in bouts of good seeing I could trace the Cassini Division atleast halfway from the rings ansae to the point where the meet the globe. I increased mag to 353x, dare I say that during 1 single split second moment I got a perfectly sharp view!!!! I saw a number of brown cloud belts and maybe a bit of limb darkening. Very good views but the seeing deteriorated before long.
Ghost of Jupiter
Strong blue hue, large outer halo with very well defined eye structure and pinpoint central star at 442x. Really cool object to view, the structure is great and I just love that colour! The Ghost of jupiter showed up really well in the 50mm finder with an 18mm plossl in place. This finderscope is going to be very useful for centering objects at high power in the main scope, also great for widefield milkyway sweeps!
Sombrero Galaxy
The moon was well up by now but at 176x the Sombrero still looked good, with the dust lane clearly visible. Should be a corker at around 200x in moonless skies
Omega Centauri
OMG!!! Unbelievable carpet of tiny pinpricks at 442x, broken up by dark lanes and features here and there! What a sight
The northern hemisphere folk don't know what they're missing!
Eight Burst Planetary
Very nice at 442x, a C-shaped ring surrounds the bright central star with an unevenly bright interior. Looks almost like what one sees in a photo, minus the techni-colour ofcourse! Also slammed the mag right up to 707x but that was just empty magnification. AN absolute pearler at 442x though.
NGC 3918
The Uranus look alike near Crux. Nice, greenish orb at 442x. I pumped the mag to 707x and dare I say the view was pretty good, same as at 442x only bigger, even with my probable crap collimation.
I even suspected a bit of structure but i don't know - that's one to revisit.
ANd that concludes a fine night of observing
I suspect this scope has killer optics - I just need a Catseye triplepack XL to make 'em dance! I might also replace the old, rusting spider/secondary assembly with a fresh product later on.
But yeah, I'm very happy with the performance of the 12", potential planet killer and mad views of deep sky