Monday, July 27, 2015

The Next Imaging List: Arp Galaxies

A quick glance at the AL list of observing programs suggested to me that the next agenda item for me is the Arp Peculiar Galaxy Northern list. This lets you image any 100 out of 338 objects in the list, which is a lot nicer than the bright nebula list. The ALBN required 100 objects out of the 132 on the list that are visible from my latitude (i.e. having a declination northward of -45 degrees). There wasn't a lot of wiggle room for the ALBN!

The submitting requirements are much saner than the BN list. Apparently all that's wanted are the images themselves. There is this strange statement:
Also, photo enhancing of your image is not required, but, again, if you choose to do so then that will be accepted.
I'm not clear about what they mean by "photo enhancing," but everyone should do at least a simple stretch. I plan on doing the usual image processing to reduce noise and get as much as I can out of the images.

Most of these objects are fairly small. The largest visible from my latitude is M101; it nicely fits into the field of  my T2i when imaged through my C 925 @ f/6.3.

My plan is to image all 100 using the same scope and imaging device. Right now I'm leaning toward using the above T2i, just for the ease of getting color.

I'd also like to use the same exposures for all the objects. There will have to be some experimentation to see what that exposure might be. If the total exposure time turns out to be short enough (10 minutes or so), I might use in-camera long exposure noise reduction (LENR) instead of dark frames.

Thursday, July 23, 2015

The Last Image from the July Road Trip

This is an image I've wanted to take for some time. Unfortunately clouds kept the total exposure time at only 63 minutes. The nebulae in the image require no introduction.

200mm Zuiko lens @ f/5.6, 63m total exposure LRGB. Taken at Jeffers Petroglyphs

Can the Summer be going by so quickly? No more travel for me (except to Cherry Grove or perhaps one of the county parks I've scouted out) until September or October. Boo!

Wednesday, July 22, 2015

Three More for the ALBN and What was Lost is Now Found

LBN 140 was something I unsuccessfully tried to image from my red zone back yard using Ha. At NSP I gave it a try because the last night it was sitting in an area that still had good transparency. The first luminance frame showed some hints of nebulosity, so I continued on and collected more.

LBN 140
Getting this was a real bonus as it has a brightness of 6 on Lynds scale. A big thank you to the dark sky of NSP!

Two objects that I tried to image at the 2015 Nebraska Star Party didn't come out thanks to a really annoying line of clouds that slowly slid over them. Luckily, the one clear night at Jeffers allowed me to go after them again. These were IC 4812 and NGC 6729, luminous parts of a larger patch of nebulosity:

IC 4812 and NGC 6729
This would have been better in the AT65, but I decided to stay with the 200mm lens.

With these two I end up at 103, three more than needed.

Still to be processed is a 200mm field LRGB image of the Lagoon/Trifid area.

Now for something strange. At NSP 2014 I lost my mount's counterweight shaft end bolt, the thing that keeps counterweights from accidentally sliding off and crushing your foot. You know, this thing:

The lost bolt, now found

The bolt can easily be replaced by a bolt and washer (google and you'll see a lot of images of replacements), but it has the same specs as the bolt on my old CG5 mount, so I used that one as a replacement. However, knowing that I'd be going back to NSP again this year I began to entertain a notion that I might find my lost bolt. I know, NSP is a big place in which to find such a small thing, they don't mow the observing fields all that short, and there's been a year for it to get trampled, corroded, covered with dirt, or otherwise abused and knocked around. A bird might have decided to carry off the shiny thing. Realistically, chances of finding it were slim.

Maybe it was the small chance of finding the bolt that compelled me to look for it. Or maybe I just really hate losing things. So I set up camp as close to where I was last year as I could remember, put up my tent and set out my mount and observing table in the same relative positions. Of course I immediately searched the area under the mount and table with great expectation. Okay, that was unrealistic.

I began a not very methodical search extending outward from the mount and within a minute saw the bolt gleaming up at me, oriented as in the above picture, shining like a tiny mirror reflecting sunlight. It was only about ten feet away from this year's placement of the mount.

Had it been cloudy or I had been farther off in my positioning I might not have seen it.

As you can see in the image above, it picked up a little rust on the threads during its year of idle time in the wilds of Nebraska. Otherwise it's fine.

This year--so far as I know--I left nothing behind at NSP. But I think I'll go back again next year anyway.

Monday, July 20, 2015

AL Bright Nebula Observing Program DONE!

Finally! I've now imaged 100 of the "Bright" nebula objects.

There were only a handful of hours with clear (if not very transparent) skies at this year's Nebraska Star Party, but it was all I needed. I shot groups of objects in Scorpius and Sagittarius/Serpens to collect the six objects I needed.

Here's the first group, NGC 6357 (the Lobster), Sh 2-12, and Sh 2-13.

And here's the second group, IC 4701, LBN 53, and LBN 70

Still to process are a possible three objects, one from NSP and the other two from Jeffers Petroglyphs. The total integration time to reach 100 objects was 180.6 hours. That's a bit over 7.5 DAYS of exposure time!

Sunday, July 19, 2015

Nebraska Star Party, 2015

Just back from NSP by way of Jeffers Petroglyphs (in Minnesota).

The Bad: This NSP did not have cooperative skies. I arrived Monday, and that night had about two hours of decent sky for imaging my southern targets--visual observers who can dodge clouds had a better evening. Tuesday night was cloudy with a threat of severe weather; many people fled their tents on hilltops and spent the night in low areas. As it turned out the bad weather never materialized. Wednesday night was cloudy, with a distant thunderstorm lighting up the sky around 2:30 A.M. Thursday night had promise, but a high cirrus layer with some opaque streaks cut the transparency to poor or worse.

NSP 2015 typical Sunset sky, a preview of the evening's coming lack of transparency

A big storm passing to the south at sunset on Tuesday.
Word was that the nights leading up to the "official" NSP week were clouded out as well.

The Good: This NSP had an attendance of about 275, reported to be the largest in ten years. (David Knisely reports attendance was 286--see Cloudy Nights.) The Wednesday speakers were excellent, and the program included a live stream of a New Horizons press conference.

I discovered the Valentine Public Library and spent a couple of mornings there in air conditioned comfort catching up on email and the news.

Imaging went only so-so. I think I finished my 100 AL Bright Nebula objects. It's not official yet as I haven't had time to process the images. I did have time to get a few extra objects, so I may end up with a total of 103. It's all luminance because of the conditions, though. I'll be posting the processed images tomorrow.

And how was the weather? Let's compare with the averages...
              Averages  Records   --- 2015 Observations ---
Date          High Low  High Low  High Low Departure Precip
July 12 (Sun) 89   60   109  42    94  68     +6     trace
July 13 (Mon) 89   60   107  41    93  57      0     none
July 14 (Tue) 89   61   105  44    90  60      0     none
July 15 (Wed) 89   61   110  40    79  66     -2     trace
July 16 (Thu) 89   61   113  45    88  60     -1     none

Very normal, really. A little warm at first, then cooler. It rained on Sunday night and unfortunately also on Friday, the public night. Overall the period was  more humid than normal with dew point temperatures in the upper 60s sliding down to the upper 50s.

The poor weather continued into my Friday at Jeffers Petroglyphs, where it was hot and humid (90F with a 73F dew point) and rain and severe weather was possible. I decided to return home, then drove back to Jeffers for Saturday. Once again it turned out that there was no rain, much less severe storms. Saturday night varied between episodes of sparkling clarity and hazy lack of transparancy that resembled NSP's weather. I collected 200mm LRGB frames of the Lagoon/Trifid area and reimaged one of the "bonus" objects that had been partially obscured at NSP.

Sad to say  that 2015 may be the last of the annual Jeffers gatherings once known as the Prairie Grass Stargaze.