NFeeder Progress; A Good Imaging Night at Last?

I added more to the Nebulosity script generator/feeder program NFeeder:

• It now recognizes the time lapse setting, although I really don't understand the implementation of this in Nebulosity. (If you specify an exposure time of 15 seconds and a time lapse of 120 seconds, consecutive exposures start at 150s intervals. Time lapse is usually taken to be the time between consecutive frame starts. An alternative would be to treat it like a delay, setting the time between when a frame ends and the next starts. In the example this would give 135s between consecutive frame starts. I can't think of a rationale for 150s between frame starts given a time lapse setting of 120s.)
• The status indicator now tries to show you when you're within a time lapse delay, although the above problem messes it up.
• It can now parse a loaded script and set all the GUI widgets accordingly.
• It now provides the total amount of exposure time the script will require and includes it in the script as a comment. At present it doesn't distinguish between light, dark, and bias frames; they all count as exposure time. I may change this. Nor does it take into account the time lapse setting. I assume total time when time lapse imaging is not as important as the clock time span of the session.
• Auto-cooldown is now implemented. You specify the ambient temperature (to within the nearest 5 degree multiple), the set point, and the size of the temperature and time steps. You can also specify a final time interval to allow the camera to come to thermal equilibrium once it's been set to the set point temperature. The values of time delays must be found empirically. The following issue with the Delay command may impact how well this works--if it works at all.
• I eliminated the possibility of delays after filter changes because of strange behavior by Nebulosity. Invoking the Delay command from clipboard commands seems to cause Nebulosity to ignore the clipboard for quite a bit longer than the delay itself. It's possible I may have to apply a workaround in which NFeeder itself provides the delays.

It's now in its fourth incarnation so it has a version number of 0.4! If you choose to download and try it, be aware that the help information is not up to date and won't be until the development of the beta is almost done.

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Imaging tonight? Beautiful clear sky and a temperature around 30F now, but it will be falling through the upper teens and remain quite breezy when it gets dark.  Almost a first quarter moon, too. But fine for a 135mm Ha image of Sh 2-264, the big patch of nebulosity around Orion's head. It will be nice to get another winter object done.

Imaging at the 4M

The 4M is the MAS (Minnesota Astronomical Society) Mini Messier Marathon. It takes place annually during the fall when it's the second time of the year one can see a large number of Messier objects in one night. In Minnesota the fall marathon usually has much nicer weather; in spring, the observing field can be under a foot or more of snow, or it can be a soggy mess thanks to snow melt. The wind chill can be -25F.

This year the 4M was very nice. Temperatures were in the 60s, the ground was soft but not too wet, and a gentle breeze kept the dew from forming. Mosquitoes were at a minimum--I noticed only a few, and that was only during the early evening. Clouds spread overhead at sunset and persisted until a little before 10 P.M., at which time it was a scramble to get my imaging gear going before I lost too much more time on the southern objects I was going for.
Because the transparency was poor and time was limited I opted to go for only one of my southern targets, Sh 2-46, a fairly bright (LBN brightness 3) emission nebula in Serpens Cauda. With almost no time for it I opted to image it only in luminance. I had to end imaging after 39 minutes because it was sinking into the low-altitude murk and starting to lose brightness.

I stayed west of the meridian to get LBN 113, another emission nebula that almost three hours of Ha could not catch in my back yard. This time I went with a different plan, L binned 2x2 and RGB binned 3x3. I used equal total exposure times for L and RGB, 15x180s. The results were better than I expected:

Top: Sh 2-46. Bottom: LBN 113.

2-46 is the unimpressive light patch just below the center of the image. 113 straddles the yellow star near the image's center. The bright blue star to its right is theta Aql.

These took me to almost midnight, so the evening was still young. By that time M45 was well up, and a difficult object  I wanted, IC 353, was right beside it. It didn't take long to acquire the object and begin shooting. 

However, I made a bad mistake at this time. The scope and camera had to move quite a bit to swing from west to east of the meridian, and in that flip the camera's sensor plane went out of orthogonality with the optical axis. Focus was no longer anything like crisp across the field, and there was some astigmatism introduced. I should have checked everything over, but in my haste I didn't.

After I was done with IC 353, I was getting tired and decided to image something bright. IC 405 in Auriga was up now, and that became my target:

Top: IC 353. Bottom: IC 405 (Flaming Star Nebula)

IC 405 deserves more exposure time, but that will have to wait until another night. By the time I was done with 405 it was 2:44 A.M., and I was ready to call it a night. all but a handful of marathoners had packed it in for the night by this time, so I decided to join them.

Three of these are new AL Bright nebula list images for me, and the image of LBN 113 replaces my earlier attempt. I'm left with only one shaky image, in my opinion, that of Barnard's Loop. It's plainly in the image, but it could look so much nicer!

What's next? The seasonal dry spell in AL Bright Nebular list objects will last for another month or so. Things really start to pick up in November. If there are some clear nights another trip to Cherry Grove may allow me to pick up some fading summer objects. Cherry Grove is only modestly dark, but it's dark enough to allow LRGB imaging. 

LBN 434 is a no-show.

Last night I went after two AL BN items, IC 1287 and LBN 434. 1287, a dim reflection nebula, was an almost hopeless task thanks to the trees and the very hazy sky. I collected some light frames, but not nearly enough. The frames were so bad looking that I haven't bothered to process them.

LBN 434 is a Lynds brightness 6 nebula, and I'm beginning to think that category 6 means anything dimmer than a 5. Maybe a better classification for 434 would be a scale extension to 7 or 8. Three hours of 5-minute H alpha exposures turned up nothing at all but stars and a couple of galaxies.

The object does show up in the Digitized Sky Survey, which is more than some cat 6 objects can say. (Evidently not all cat 6s are created equal.) After some work I was able to confirm that I was imaging the correct field. Processing the image beyond all reason might show a trace of the brightest part of the nebula, but it's not nearly solid enough to submit as acquired. The object was simply too dim for me to catch under my bright hazy skies.

I may go after 1287 from a dark site, but 434 is now on my list to not revisit unless I'm desperately short of objects on the way to the required 100.

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My mosaic of LBN 270 proved to be modestly popular on AstroBin, garnering more "likes" than any other image I've made.

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My next backyard target is going to be more fun, going after M 57 to image the outer shells. This will be a multi-night task, with a lot of unbinned H alpha work at various exposure times, and then possibly the same with binned color. I'll use my C 925 without its reducer/flattener for maximum scale, and because at f/10 the ring can sit happily within the central part of the field.

Sh 2-137

The list rolls on with another faint nebula: Sh 2-137 in Cepheus. This object its also known as LBN 498 and has a brightness value of 5

This images represents 3.5 hours of integration on a night with a bright waning gibbous moon.

Sh 2-137

The bright star at left is GSC 04271-2621 with magnitude 4.57.

Another Obscure "Bright" Nebula: LBN 185, and IC 1470

The AL Bright Nebula list has quite a few not-very-bright nebulae on it. Here's one that's bright enough to image from a red zone + a nearly full moon: LBN 185 in Cygnus, a 5 on the LBN brightness scale.

LBN 185

I believe LBN 185 is the bright area near the center of the image. There's another bright area at the left edge of the image, but so far as I know that has no designation. This took 3.8 hours of H alpha imaging, and even at that the background is still rather rough. A couple of nights before I also got this image of IC 1470:

IC 1470

On the other hand, IC 1470 is bright, and small. This was taken with a C925 at a focal length of 1480mm, while the LBN 185 image is wide field with a 422mm AT65EDQ.

Finally!

This is the first image of the year! Let's just say it's been a bad year. Amazingly everything worked smoothly, including me. This is yet another AL Bright nebular object, LBN 331.

A so-so picture, but I'll take it--LBN 331 is a brightness 4 object, so given my skies I don't expect much from 1.6 hours total exposure.

LBN 331

Details are here.

Tonight's supposed to be clear again (we'll see), so with luck I can bag another object, or go back to this one and shoot some RGB so that the stars have color.

Goodbye to the AT72ED

Two years ago I purchased a used AT72ED. The scope I wanted was the AT65EDQ, but it was too pricey for my budget.

The AT72 was an able performer when paired with the Orion Field Flattener for Short Refractors (see my Andromeda Galaxy image in this blog post. I didn't care for the mounting foot, but it was easy to replace with rings. The focuser was no Moonlite but it held my heavy CCD + Filter wheel without problems. If it had a fault it was a little blue haloing on brighter stars. (I can't be sure if that wasn't my fault for not being a diligent focuser.)

Eventually a local club member decided to part with his AT65 and I was able to pick it up for not much more than the AT72 cost me. This made the AT72 expendable and I put it up for sale. I let it sit idle for a while on the club's merchandise forum. Finally this fall I listed it on Cloudy Nights and it sold along with the FF. The new owner is interested in using it to get into wide-field DSLR astrophotography, for which it's wonderfully suited.

The AT65 has been great this fall for chasing down the larger Astronomical League Bright Nebula objects. I recommend it to anyone who wants to get into imaging without spending a lot on an expensive telescope.

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One of my telescopes is becoming something of an orphan. My old ShortTube 80, originally purchased as a travel scope to take to the 1998 Solar Eclipse in Aruba, doesn't have a role any longer. I'm holding onto it for now because it's still a good travel scope, and it's great as a guide scope. The Orion mini-guider has replaced the ST on my refractors, but I'm uncertain if the little scope will work well with my C925. That determination will have to wait for the summer when the weather is better.

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Speaking of the weather, it's not been helpful. I got the usual fall head cold a couple of weeks before Thanksgiving. Then after the holiday the weather turned cold (frequently going sub-zero). I can handle temperatures down to around 10 degrees F, but zero is outside my optimal range of operation. Cold and Clouds have continued all December. I'm hoping for a better 2014!

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Oh yes, one more thing. Astrobin did a major reworking of their site code and all my image links are now broken. I'll be fixing them as time permits.

Working on the AL Bright Nebula List

The last week has been amazing for this part of the world in that it's been clear six nights in a row. This has given me the opportunity to get my AL BN list work underway. Here are some of the results:

The Crescent Nebula

The Crescent is a bi-color shot (Ha and OIII) with synthetic green.

The Propeller

The Propeller is a fairly bright and decidedly strange looking nebula.

The Elephant's Trunk

The Elephant's Trunk is a much-imaged object, and this is one of my poorer efforts. Polar alignment was far off and the drift has caused artifacts in the image.

The Cocoon Nebula

The Cocoon is another popular target because the emission nebula at its heart is so bright. This image was composed to emphasize the dark lane (Barnard 168) extending westward from it.

Details for these images can be found on my AstroBin pages.

Most of my AL BN imaging will be in H alpha only. This is because my sky is very bright (urban/suburban) and some of the nebulae are very dim. So far I've been shooting mostly large objects with my AT65EDQ and will soon move on to smaller targets using my C925.

I've started using PHD guiding to do my polar alignment. All in all it seems to work very well, but I've found that the instructions for doing the alignment are generally incomplete. I'll see if after some experimenting I can write up something better.