I had a bunch of maintenance piling up in the obvservatory, so I decided to do some of it since it’s raining all weekend.

I spent a little time getting the mount more level, and adjusting the elevation on the polar alignment. I still don’t think it’s perfect, but I think I’m closer.

The polar alignment still needs adjustment in azimuth, and a final check in elevation.

I installed the new EEPROM (v1.04; apparently 1.05 is only from Goerlich) and a new battery in the mount. I also hooked up the GPS and got the time and location correct.

I mounted up the new autoguider and tried to take a couple of daytime shots to test it out, but the observatory computer fried, so I spent the time to rebuild the observatory machine from the ground up. That took longer than I expected, but I think it’s up and running now. I was having an awful time trying to get VNC to work properly. It was running really slowly on a fresh install of Win XP SP3. After much gnashing of teeth and tearing of hair, I rebooted all the elements of the LAN (modem, router, etc), tweaked the firewall on the new machine, and installed several Windows and Dell updates. Something in there “clicked”, and now it’s up again and fast as ever.

I took the C9.25 to a local park and set up the artificial star about 75yd away. That was more than enough to get me in focus, and with a few tweaks of the collimation knobs, I saw, for the first time, *perfect* Airy disks! I was collimating at 700x, so gorgeous. The C9.25 is ready for… something. It’s back in its (new) case for now, but ready to rock.

Buoyed by that success, I decided to try to collimate Veronica, too. This was not as successful. I will have to read up on collimation, because the closest I could get to Airy disks was seeing little tiny “crosses” (even on the dimmest light), which merged “vertical” if I went one way out of focus, and “horizontal” if I went the other way. There is a ton of light being thrown off outside of the 4 main diffraction spikes, too. I think I’m closer, but I will be using the C9.25 or Pumpkin to do polar alignment and pointing models for awhile…

A very productive weekend, despite only having 90 minutes of clear sky.

Well, I think I finally nailed the polar alignment.

A: 1 E: -1

Here are the rest of the modeling parameters:
dH 26′
dD -2′
NE 33′ (Axis non-perpendicularity at the equator)
NP -7′ (Axis non-perpendicularity at the pole)
IH -35′ (Index error in hour angle)
ID -3′ (Index error in declination)
CF -3′ (Counterweight flexure)
FR 44′ (Mirror flop/Gear play in RA)
FD -0′ (Mirror flop/Gear play in Dec)

I looked up the definitions for all this, but I’m not entirely certain what it means, or how normal any of these numbers are.

With the newly-tuned mount, I decided to try Pumpkin on some more unguided imaging. After the “baseline” from the previous night, I now wanted to see what this MFWB could really do.

M42 was a bit far west and covered with clouds by the time I got Pumpkin up and running (I had a pretty funny motor stall that wigged me out momentarily — in my haste to get imaging after testing Trixie, I had forgotten to swap out the counterweights, so 10# Pumpkin was offsetting 43# of counterweight… oops), so I decided to see if I could work The Rosette for a bit instead.

This time, I centered the cluster that I could see in the finder. This proved to be a good decision:

That’s 12 five min subframes, one hour of integration time. Rosette, you are mine.

I picked up some wispy outer nebulosity, too, that is easier to see in inverse:

Still a bit noisy. I’d like to apply a full calibration set on this, and have about 3 hours of integration time to work with.

This was shot under an 8-day moon.

The image is unguided.

I mounted up Pumpkin by herself tonight. The mount’s been having a problem with guiding, very rough behavior in RA. I’m going to be tuning the mount up tomorrow, but the sky was clear, so I decided to see if it behaved a little better with just one tiny little scope onboard.

Because I also don’t have an OAG at the moment (I’m picking it up tomorrow), this was an unguided test.

I started out, as is normal, with a shot at M42. The pointing model was a little rough, so the nebula is off-center. The mount was so far west by this point (and the clouds were rolling in and out so much) that I only got 2 frames of M42, so this is a fairly noisy 10min integration:

To emphasize some of the wispy nebular detail, I inverted the photo, also:

…nice. I do like these Astronomik Ha filters. This is with the clip-in.

Once M42 was too far west, I switched to The Rosette. I need to learn the star patterns around this object, because I thought I could see the star cluster off to the right in the finder scope, but I wasn’t sure, so…

Yep, another swing-and-a-miss. The Rosette is quickly taking on the Nemesis status that The North America Nebula had for so long. Flashes of brilliance on a cool looking nebula, but a lot of near misses. Oh well. This is a 30min integration.

Aww, how cute! Pumpkin as the “main imaging scope”:

The unguided behavior is better than things have been recently. But I’m looking forward to seeing whether the MFWB helps this any.

Clear Sky Clock said it would be cloudy all night, so of course it stayed 90% clear until about midnight, when it socked in. But I’m getting ahead of myself…

I decided to get the autoguider up and running tonight. I wanted everything focused and aligned so that I can get started shooting again for real.

On top of this desire, my new clip-in Ha filter showed up today, and I really wanted to try it out!

So I hooked up the autoguider, got it all focused and balanced the rig. I booted up the scope, which wanted to cold-start again. No problem. Quick slew to Betelgeuse… and that’s where the problems started.

For some reason, the main scope and its finder (which were aligned as recently as 2 days ago, and have not been touched) are no longer in alignment. No problem; I see the star in the finder, I’ll just sweep the scope around until I find it.

No dice.

I don’t know what my problem was, but I tried everything I could think of, including sweeping the scope by hand, and I could not find *anything*. It took me 40 minutes to finally stumble over Rigel and then get the finder and scope aligned. While that was in the vicinity, I set up the guide scope to be roughly aligned, too.

As part of this fun, I figured out that the reticle is not centered in the guiding eyepiece. Again. That is a silly feature. But I figured out how to get it centered, so now the guide finder, guide scope, and reticle eyepiece all agree about the center of the field. Which is nice.

So after losing about 45 minutes of clear sky, I got the scope turned on and started an alignment run… the deep cycle battery died. argh. OK, set up the 15v power supply — deal with the battery later. Now I’m working the alignment (oh, I had mis-calculated GMT earlier in the evening, too — I was having a bit of a day), and the polar alignment is way off compared to a few days ago. Pulled out the polar alignment scope illuminator, and it’s got a busted power cable. Again. That is the worst design ever. I decided to just go forward with it; I’ll deal with polar alignment later. I need to be using my Gizmo anyway. Where is that thing? hmm…

OK, so I’m aligned. I boot up the computer, and shoot a test image of Betelgeuse through the Ha filter. It is of course not in focus. No problem. Fire up FocusMax (nothing can go wrong with the focuser — it’s on COM1), and …

all of the FocusMax windows show up offscreen. I have no idea why. I even tried to Regedit them into place; no dice. Meanwhile, tick, tick, tick, clear sky still, but I can see clouds moving in. Also, Orion is now well past meridian. grr!

Fine. I fire up the focuser in MaxIM (I tried to get the ST-4 and mount working in MaxIM, too, but needed to reinstall the USB-to-Serial drivers for reasons passing understanding, and never got that working right — you guessed it, deal with it later), did an autofocus run in MaxIM for the first time ever.

Let me say at this point that I really like the new MaxIM focus routine. It brings up a V-curve just like FocusMax, and while it seems to converge on a solution a little more slowly, it does seem to get there pretty well, as evidenced by the fact that in just a few minutes, I had autofocused the Ha filter on Betelgeuse! (FWHM of ~5.5, high winds and encroaching clouds and sketchy collimation, so give me a break, this is about what I usually get)

So I fired a 40sec exposure of Betelgeuse, so I could see some diffraction spikes, and got a bright fuzzy ball with lots of stars in the background. I looked up, and couldn’t even see the star through the cloud cover. OK, I get it. So I slewed over to M42 anyway, because I was going to make sure I was in focus.

A couple of 40sec and then 2min frames of M42 looked pretty good given they were clearly destroyed by clouds.

I tried to set up the ST-4, but it spent a lot of time losing the star and giving me “E E” followed by “-E -E” type corrections, so I turned it off. I only like guiding in MaxIM if I can help it.

At this point, it was about midnight, and we get to where I started this post… socked in solid with clouds, and no images to show for it.

And a longer todo list.

But a few more things are set up again, including of all things, the autofocus routine in MaxIM! Cool.

Fingers crossed for a clear night this weekend. Next one won’t be wasted.

Given my strange “bell-curve” style tracking errors that I was getting last spring/summer, I am unconvinced that my mount is the source of the problem. I need to find and kill the flexure problem first, then I can worry about the mount again.

Having said that, I have several updates/upgrades/fixes to do to the mount:
- remove DSCH encoders and replace with spacers
- replace RA gearbox with the one Art sent
- replace RA bearings with the ones Art sent
- make decisions about which worms to use where (I have 3 precision steel worms, and 1 brass one)

Once all that is in or not, I can decide if there is anything else I need to do to the mount, in particular:
- Ovision or MWB worm/worm block (or blocks)
- Maxxon motors

- Gemini firmware upgrade

I have a sneaking suspicion that my setup is actually pretty good. I just need to take everything to the next level in order to deal with the longer exposures I can get out of the narrowband rig.

I stacked the 16 frames shot last night into a single GIF animation. There is a very strange “retrograde motion” thing going on during the course of an evening.

I don’t know what’s causing it, although candidates now include:
- balance (been messing with this for 3 days with no perceiveable difference in the problem)

- pointing model (is there something bad built in?)
- motor speed (ie runs too fast/slow)
- tracking speed (ie Sidereal vs King?)
- guide magnification (add barlow)
- tube flexure
- bad spots on the RA gear (am I hitting the same section of the gear every night?)

I’m sure there are others.

Here’s the animation. I didn’t include it inline because it’s 500K and who wants to download a thumbnail that big?

If you have seen this before, please let me know.

I’m having a tracking problem with the mount. This is all eerily familiar. Things run fine for a couple of hours and then the wheels fall off.

This results in only being able to use a fraction of the frames that I shoot in a given session. Very irritating.

I adjusted the counterweights last night, making the mount slightly heavy to the east, rather than being in perfect balance. I am told that this keeps the RA gears meshed, which helps the tracking. Perhaps I didn’t find the sweet spot of east-heaviness. Perhaps the whole concept is hooey. All I know is, I again lost 2/3 of my frames; what follows is a stack of frames 3,4,5, and 7 out of 16.

I adjusted the CW back to near balance when I shut things down.

On a slightly positive note, the mount hit its safety limit and stopped tracking before touching the pier this morning. This is a function of where the object is in the sky, but joy anyway.

Last month’s shot through Pumpkin shows, as usual, much more context around the target.

NGC 6888, The Crescent Nebula in Cygnus

Another nice Ha image, another night where I’m a little disappointed in the mount’s performance. I may have to tweak the balance a little more.

Saturday was cloudy, but Sunday night was clear, so I set up the scopes for another night of photography.

I decided to shoot Sh2-101, The Tulip Nebula. I am still working on figuring out what Veronica’s FOV is compared to Pumpkin’s. This nebula turns out to be nicely-framed in Veronica’s FOV, big enough to show detail without cropping, small enough that it’s not difficult to cram in. As usual, Veronica is the workhorse telescope she’s been for me for 5 years now.

I am having some kind of strange error on the mount — it works fine for about 2 hours, then goes nutty and all the images have trailed stars after that. On Friday night, where it was pretty cloudy, I was willing to blame the clouds for this. But I didn’t see any clouds on Sunday (which is not to say they didn’t appear after I fell asleep). I worry that I’m having a cable-pulling problem or some kind of imbalance thing going on. This will take further investigation, but I’m quite frustrated that essentially I am wasting 2/3 of my shots (and all of the ones after I turn in). Again, this image is 6×20m, a full 2 hours, but I threw away another 9 or 10 images that were on target but with trailed stars. I’ll play with the balance and see if that does anything.

Anyway, such as it is, here is last night’s image:

Compare to my previous shot. It’s a different kind of “feel” between the two images — Veronica highlights the brightest part of the nebula, and produces lots more detail because of the extra magnification. Pumpkin gives much more context to the area, and I certainly never would have known about all that wispy dust lane detail if I’d only seen the Veronica image.

It seems that the two scopes match each other in resolution pretty well. I’m looking forward to more Cygnus hunting with Veronica this month!

I was running out of ideas of things to shoot; I’m getting pretty worn out from several nights in a row of being up late shooting, and I’m starting to make bad decisions about target selection.

Anyway, after thrashing around a little (I considered shooting Rho Ophiucus and also some stuff that was skimming the rooftops in Cepheus), I settled on a nice, easy to find target.

NGC6888, The Crescent Nebula, is an old friend. Click the link for some previous photos.

Obviously, Pumpkin’s wide FOV was going to produce a much different image of the area. In fact, the field was wide enough to pick up bright Sadr, the “center of the cross” in Cygnus. That’s the obviously-brightest star in the field, at upper left.

My previous attempts at NGC 6888 hinted at some extra, dim nebulosity in the area, but I was pretty pleased with how much I picked up here.

One thing I’ve noticed (it’s particularly noticeable in this image) is that, although I have a field flattener in place, the field is still noticeably curved, which is why the stars at the edge of the frame are so much larger than the ones at the center. I can play around some with the distance between the flattener and the CCD, but I think this might be something that I just have to live with. Pumpkin is a really nice scope, and doing an excellent job for me as an astrograph, but this is the difference, I suppose, between a $300 scope and a $3000 scope.

All told, a very nice image.