I have avoided the Virgo Galaxies for years. The reasons are many, but chief among them is that a lot of the Virgo galaxies are elliptical, which essentially means that they look like almost nothing when you photograph them. Spirals are much more photogenic, and as should be clear if you’ve followed my target selection in this blog over the years, I’m in it for photogenic objects, not so much for a scientific exploration or any sort of “full collection” of anything.

OK, enough said. I’ve covered all that before.

M87 is a gigantic elliptical galaxy, maybe the largest object in the Virgo Cluster (?). It’s also famous because it has a jet of material coming out of its core. Hubble shot an excellent photo of this jet at one point or another. I wanted to know whether I could capture it, too.

Also, since I know that there are dozens of galaxies around the area, I wanted to start to get comfortable in Virgo, and in particular I wanted to see if I could find any spirals worth shooting over there.

So, off to M87 I went. I used Elbrus, my new “plate solving” software, to refine my GOTOs in the area. All I can say is that Elbrus is a game-changer, when it’s configured properly. That will come with time, but at the moment, every new object means I have to manually calibrate 3 nearby stars before it can do anything. Once it’s on, it’s really on.

I used my newfound information about exactly where I was pointing to pull in a small galaxy cluster that would have otherwise been off the edge of the frame to the west. Nifty!

I had the mount “bend over backwards” to pick up the target, so that I could get maximum imaging time on it. I ended up being able to shoot for nearly 4 hours before the mount hit its safety limit and stopped tracking (just like it was supposed to!).

This is M87, 43x5m subframes = 3h 35m total exposure time. I was using 5m subframes because I’m not shooting in Ha. Note that I also have a gnarly color gradient. Someday I will learn to process images better. (:

This is an annotated version of the image, showing all the other faint fuzzies I picked up — only NGC4440 is noticeably a spiral to my eye:

…and finally, here is a full-zoom crop of M87 and environs. You can clearly see the beginning of the jet going off to the right, near M87′s core. Also note that there are 2 little baby galaxies right below M87. These were not marked on either of the two star charts I used to annotate the image. Maybe I will spend some more time looking up their designations. Otherwise, they become “The Harris Galaxies”. (:

Everything worked right last night. 4026 punches out 5m subframes like it’s bored. The new safety limits are working great. The plate solving makes my heart skip when I watch it go. Even the image processing, despite ending up with a gradient, went pretty well.

I’m happy.

More Galaxy-hunting in Virgo to commence.

I tried some new stuff last night and screwed myself up.
I was all mounted and focused, so I decided to work a nice easy object, and chose M81.

M81 was near zenith, so I decided to shoot West instead of East, so that I could get maximum imaging time without scope running into mount.

The tracking was looking great as normal, but the mount was *not* behaving; every one of the 20m images was trailed. I switched to 5m images, and of course (the things we take for granted) those worked fine. I didn’t want to have to wrestle 60 images in the morning, though, so I switched again to 10m, and those looked like they’d be fine. Set it up for 30 images and went to bed around midnight.

I ran out of time this morning during image processing; I have a 23Mb PNG file that I was going to do my processing mojo on to see what I got. But I only have GIMP at work, and it doesn’t do the same job that Photoshop does. I’ll process it tonight when I get home.

I’m confused about the tracking errors. I think maybe MaxIM screwed me with the “Scope Dec” thing. I dunno. Clearly I have more to learn about this mount and the sky and how stuff works.

In order to get maximum time on the whole tracking thing, I got the mount to “bend over backwards” to pick up M81 still east of zenith. It took a little finagling to get it to go. First it thought the scope was pointed East (and was doing backwards GOTOs), then it gave me some “meridian flip required” stuff, but eventually I got it to GOTO M81 in steps (sync on Dubhe, GOTO a star between Dubhe and M81. Center the star, sync on that. Then slew to M81).

I still don’t understand the meridian behavior of the mount, and the Tak group is ignoring me.

shrug. I’ll play around with it in daylight, and figure out how the settings affect things.

I woke up this morning and the mount was still tracking in RA, nearly CW down with the scope low enough that I could almost close the roof without moving it off of M81. Max was sitting there with a “dark frame required” since it finished its run at 5am. I should have gone for 36 images. sigh.

I will have to look at the individual frames more closely, but I do believe that I’ve gotten another 30 perfect subframes out of 4026. Works for me.

…with zero dropped subframes.

I spent a little time refining the polar alignment last night. I am still getting some drift while running unguided; I calculated it to be about 6′ from the pole now.

The guiding is even smoother now, if one could believe it possible.

I shot 20m subframes all night. I ended up with 5 frames of M51 (OK, but not worth posting). By the time M51 was finished (around 2am), Cygnus was up, and so I went and grabbed 10(!) more frames of Sh2-101.

The 3h 20m image came out pretty nice, but as always it could use some more integration time:

This is one of my standard 1500×1000 -> 900×600 crop-and-size jobs. There was a lot more context in the image, but Veronica is badly out of collimation at the moment, so there were some badly mangled stars; this is as good as I could get.

Things I noted last night:
- the pier topper needs to be rotated about 1/2″ clockwise, because the azimuth adjustment has run out of room to the west.
- Veronica needs to be recollimated. I am going to pull the long bolts and put the stock ones back in. I think I’m done with the RCC/OAG.
- I am not certain if it did anything bad, but I pulled the webcam out of the OAG and put it into the main focuser partway through the night. I would think that it doesn’t matter where in the FOV the star lies, but better safe than sorry.
- I will not be putting the mount on the tripod for tonight’s star party. I think it’s more impressive on the pier.
- One of the GOTOs last night was so accurate that I looked in the finder, couldn’t find the star, started pushing it around with the hand controller, and realized it was sitting behind the crosshairs. (:
- The mount put up more gaudy numbers; 0.4″ RMS for the night. wow.

A good night. And I got an hour more sleep and still hit a Cygnus target!

FocusMax worked.
PemPro worked.
Guido worked.

I shot M106 (through Pumpkin — tiny, tiny) until the mount hit the safety limit, 150m total or so.

Then, since it was still clear (although a bit late), I went hunting for another target, and landed on Sh2-115 in Cygnus (a target that should not be possible to shoot in early March). I hoped to shoot some color frames to back up the Ha I shot last spring. I misframed slightly, but we’ll see what comes out.

The camera is out shooting darks and biases, then I’ll have some new photos to process.

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.

The skies cleared again tonight! Second time in a week, with about 2 weeks of continual rain going on around them. Interesting.

The moon is one day before 1st quarter, so I got a good chance to get Trixie out and took a peek at the moon for the first time with her. Very nice. Here’s the photo:

From this photo, I could see by inspection that the scope is out of collimation. To confirm, I shot a photo of Aldebaran:

No problem. I will spend tomorrow tuning.

Once I’d convinced myself that Trixie is ready for a tuneup, I decided to use the rest of the clear sky to do some imaging. Since Veronica+Pumpkin+guider is not really working, I mounted up Pumpkin by herself (a first!) and set up for some Ha widefields in the winter Milky Way.

I should have some pixels of M42 and The Rosette on the way… but that’s another post.

It’s good to be under the sky again. Very clean air out there tonight.

After speaking with Art tonight about my guiding workflow, it seems that I have been doing things… in a manner which would probably give me problems if I tried to do longish exposures.

Art has been talking to me for years about how he always guides on a star that is in the same field of view as the object he’s imaging.

This has always sounded like a mixture of hubris and idiocy to me, since the ST-4 can’t seem to pick up any stars that I can’t see in the finder (about mag 6 or brighter), which means I essentially *never* guide on a star in the same FOV as the target object.

We finally hashed it out, and I realized that I made two errors that compounded upon each other.

The first error is that I have been using guide exposures of less than 0.5sec. This comes from my CloudyNights background of trying to force a webcam to do a guider’s work. Webcams have a max exposure time of 0.2sec, so a beginner imager using one is restricted to guiding on bright stars, but that’s OK because they are also probably going to be limited in their total exposure time per subframe by other things, like a beginner mount, a beginner imaging camera, etc. I don’t have a beginner’s guider, but the way I learned to use it was by talking with people who do. There are a lot of myths about astrophotography out there. I’m good at seeing most of them, but this one I missed.

Because of the short guide exposures, I was having trouble finding bright enough guidestars. That led to the second error, which is pointing the guidescope and the main scope in slightly different directions, so that the main scope is over the target, and the guidescope is over a sufficiently bright star.

For subframes less than 3 minutes or so, having the guidescope and main scope pointing in slightly different directions does not make a difference. Sure, over the course of the night, you’ll see the object drifting around the FOV, but that’s what stacking software is for, right?

Now that I’m hitting the end of that “beginner” type workflow, and asking the rig to do 5, 10, and 20 minute subframes, this method of guiding is leading to problems with orthogonality. That is, since the guidescope is now not aligned with the same polar axis as the rest of the mount, it appears to be misaligned from the NCP, and thus sends spurious guide commands to the mount.

No matter which scope I had doing the guiding, I was doing the same thing (misaligning the two scopes), so I was seeing the same type of problem, trailed stars that move in an elliptical “orbit” over the course of the night.

The answer is clear. Always point the guidescope and main scope in the same direction, period.

This means that I will have to find a guidestar that is close to the object I need to image.

And in order to do that, I will need to use longer guider exposures, on the order of 2-5sec. The longer exposures will mean that calibrating the guide images will be key, so darks (and maybe bias and flats, too) will need to be shot for the guide camera.

However, longer images should mean that I’ll be able to pick up dimmer stars, and hopefully will be able to find a star in every FOV.

I still won’t be able to go unguided. That’s a level of mount tuning that I may never reach. But if I can get to the point where I am able to shoot subframes as long as I want, and guide my way all the way through them, that will probably be enough.

By the way, with this information in mind, the OAG probably *will* “solve” the problem I’m having with “flexure”. I would have to start using longer guide exposures when the OAG forced me to find a guidestar in the same FOV as the target…

Now I await a clear night to test this latest theory.

The seeing was pretty bad last night, as in “wind blowing so hard that I thought the leaves rattling were raindrops and ran outside to check”.

This wreaked havoc on Veronica’s guiding. So, the stars were not perfect in any of the shots, but they were all about evenly bad, and there were SIX HOURS of them.

So I decided to stack them up anyway.

This is Sh2-155, The Cave Nebula in Cepheus. This object is way down over the house early in the evening, but I imaged for so long that the telescope hit the pier again this morning. I intended to shoot Sh2-155 for just an hour or two, then swap to IC 1848 The Soul Nebula, but the seeing was awful and I decided to stick with the object, hoping that it would get better as the night dragged on.

Sh2-155, The Cave Nebula in Cepheus

18 frames. 20 minutes each. Six hours. Wow. Oh sure, the image could be a little tighter. But you gotta love li’l P and how the photons just come flowing in.

The problems with Veronica are still bothering me, but I’m trying to put that out of my mind for now, and just enjoy imaging for awhile.

After 10 days of fighting Veronica, I’d had enough. Tonight, I swapped the camera back to Pumpkin, rebalanced, and tried my luck at two targets.

With Cassiopeia showing above the house, I decided that I wanted to try for IC 1805 and IC 1848, The “Heart” and “Soul” Nebulae that lie between Cassiopeia and Perseus. Note that it’s July, not October. But, since Pumpkin seems to do pretty well (owing in no small part to the 5”/px and huge FOV and huge guidescope), and since I like to avoid running the scope into the pier, I find that I choose objects that are “a little low” and let them rise all night.

But these guys were still below my “horizon” (read: The wall of the observatory ) yet, so I needed to shoot something else for an hour or so, until Cassiopeia rose a little bit.

So, I decided to continue my widefield survey of Cygnus/Cepheus, and did an hour (back to 20m subframes — I love that li’l orange scope!) on Sh2-119.

The Sharpless nebulae are opening whole new vistas in my target list, and I’m *really* enjoying going after these objects in full knowledge that I’d probably get nothing but noise and pain if I tried this without the Ha filter.

Sh2-119 in Cygnus

I like Cygnus. It’s really good to have Pumpkin back. I have nothing more to say about this object.

Now it was late enough that I could start getting some time on Cassiopeia. Some clouds threatened to roll in, ate my guidestar for awhile, etc. Pumpkin just powered through all that. I only lost one frame out of 13 (to clouds). Since IC 1805 was laid in “horizontally”, I missed the nearby IC 1848. That’s for tomorrow night. This is a full 4 hours of Ha from Pumpkin on an object that I have no right to be shooting for another few months.

IC 1805 The Heart Nebula in Cassiopeia

In a word, Wow. I’m back on track again. I am having fun with my widefield shots in a way that I haven’t been having fun for awhile now. I want to buy an OIII filter and go back and shoot all this stuff again. I am giddy when I see the cool stuff show up in each subframe.

The guiding is a little rough. But the results speak for themselves. I am ready to shoot my way through the rest of the month. Yay!