One Channel; Dozens of Bites

Another camping trip to Lac qui Parle State Park is over and it was a partial success. Let's start with the good news first: I got the blue channel data I needed:

Blue Channel of IFN

This is based on 1.72 hours of total exposure. Blue is usually the weakest channel in terms of signal and to me this looks decent. I'll try to get about the same exposure time for green and red. The strongest blue signal seems to be in the area just below Polaris; this may make that area whitest, which would be in agreement with what I've seen in other images.

[ Compare this to the luminance channel image in the previous post. Blue looks much less contrasty, right? Consider that the blue channel has only 1/3 (or so) of  the luminance signal, and that the above is based on 69 subs compared to the luminance's 177 subs; you can roughly figure this has an equivalent exposure of only 1/8 of the luminance. It didn't get lifted nearly as far above the background, so less contrast. ]

See the copyright notice? That's because my little blog is now getting scraped two or three times every day. Probably not because it's worth scraping, but simply because it exists. I can't really do much of anything that's effective to stop it without adding a CAPTCHA-like layer that would force everyone to choose which squares are motorcycles, or traffic signals, or whatever bots can't easily distinguish. I don't like those things, so I won't subject others to them.

Now the unfortunate part of the trip. The first night's imaging ended prematurely when somehow PHD2 became convinced it was using my imaging camera as the guide camera. This wreaked havoc with things: I started getting repeated timeouts, and a couple of the frames suffered from strange excursions probably caused by calibration mismatch due to different focal lengths. I shut down the sequence and tried troubleshooting, but it was simply not happy. It was already 1:30 A.M. so I decided to give up and get it worked out the next day. Here's what the misguided guider was doing on two of the frames:

Excursions along one of the guider axes.

This was clearly along one of the guider's axes. The guiding display of corrections looked like a strong square wave. 

The next day was unpleasantly warm (almost 90 F and dead calm). I redid PHD's hardware profile and collected the new dark/bad pixel frames it demanded. Things seemed to work; there was a steady stream of images. It also needed a new calibration, something I could only do once it was dark. As dusk fell the mosquitoes attacked in force. My Coleman shelter worked reasonably well to protect me, but all this reconfiguring was making me repeatedly get in and out of the protected area, each time allowing dozens of hungry mosquitoes in. Neither the usually effective Ultrathon or DEET products kept them off me. It was not fun.

There were thunderstorms already west of me in South Dakota, the last satellite images showed high blowoff from them headed directly my way. The forecast was for rain and possibly severe weather around 5 A.M., meaning I'd have to break down everything and pack it away before turning in. 

Between all that and how the bites on my arms and hands were welting up I decided to pack it in and  get a good night's sleep. As it turned out there was rain but the severe stuff went elsewhere. I was glad to have bailed on the night. 

I don't think I'll be making any more mid-summer trips to the park, it's just too buggy for this imager. What a change it was from the previous month's visit!

I'll only have some of the July new moon to see about collecting the red and green frames as my wife is having her second knee replacement done on the day of the new moon. I'll probably just wait for the Northern Nights Star Fest at the end of August, as that should be cooler, darker, and will have longer nights. Or, if that's completely clouded out the Iowa Star Party in October or any clear, dark nights I can get out to Eagle Lake.

-----------

Tariff Watch: The Rokinon lens remains in stock at B&H at $449. This price is 22% above the February pre-tariff price, which is very close to the current tariff of 26% with South Korea.

Reservations, Smoke, and One Night of Imaging

A few things from a less than fully successful week of dark-sky camping:

Reservations

The initial state park reservations I had were for three nights starting Tuesday. Clouds and rain looked very likely to wipe out the first two nights so I cancelled the reservation and made another for 3 nights starting Thursday when the forecast was much more favorable: one iffy night followed by two that were perfect.  I decided to get everything set up and running that iffy night after seeing the Sun wink out as it set into a heavy smoke layer on the northwest horizon. This turned out to be a good move as this would be the only useable night. The heavy smoke arrived by Friday morning, when two hours after sunrise the Sun was a dim red ball you could look at directly. 

Lesson learned: Minnesota state parks offer same-day reservations.  Next time I'll wait until I'm sure the night will be clear to make my reservation.  All my things are very well organized and I can pack the car and be on the road in less than an hour. My preferred dark-sky camp, Lac qui Parle, is lightly used and usually has unpowered pull-ins available.

Mount Safety Limits

By the time I was ready to shut down that first night my mount had rotated to the point that it was well beyond its safe travel limit. This didn't really matter as looking to Polaris allows much further travel than is usually safe, and the G-11 mount tracks nicely even when it's over-rotated and the counterweight shaft is well beyond horizontal. 

That said, what I expected was a meridian flip sometime around midnight. When that didn't happen I recycled the system and expected go-to would put the scope on the correct side. It didn't. I could see that eventually I'd run the camera against the mount and decided to let it go right up to that point before stopping. 

I got enough frames that night, but in a month when I return to shoot color frames I'll have to stop even earlier in the evening. 

Lesson learned: I need to configure NINA and my Gemini-II mount control to properly handle flips.

Here are two videos that I found useful for doing this and for setting up NINA for flips:

https://www.youtube.com/watch?v=Rk8uOikHPb4

https://www.youtube.com/watch?v=0N0U5chskCQ

There's also a very useful spreadsheet available to members of the Gemini-II user group on groups.io (See the second link above for how to use the spreadsheet.)

I've made the changes to my Gemini-II and go-to now seems to put the telescope on the correct side based on the limits. Seeing if automated meridian flips work will have to wait for a night under stars.

The Coleman Bug Shelter (Previously mentioned here.)

This was my first night out with the shelter, and it worked great--no gnats, no mosquitoes inside. I sat in the shelter linked to the scope with a 16' active USB 3 cable (which was also getting its first all-night imaging test). There wasn't a single glitch. The only awkward part of this is doing polar alignment, when I (and the laptop) need to be at the mount to make adjustments. Once that's done, it's back into the Coleman. It was so comfortable in there that I spent most of the evening relaxing with a good book.

Lesson learned: I'm ready for next year's Nebraska Star Party and its all-night supply of mosquitoes. Will the shelter, even when staked down, be able to endure the winds of Nebraska?

The Results

If the Eagle Lake Observatory setting is Bortle 4 plus a bit, then Lac qui Parle with Thursday night's smoke was Bortle 4 minus a bit: definitely darker than Eagle lake, but certainly it wasn't the Bortle 3 I've seen  there before. Despite that, I gathered 113 luminance frames. Seven were discarded for being in twilight, and one was lost for poor tracking. Adding the new 105 frames to the previously collected 72 Eagle Lake frames brought me to about 4.4 hours of total luminance exposure.

Here is the result, as produced by PixInsight's WBPP and some modest postprocessing of my own:

IFN (luminance, 4.4 hours)

This is much better than my 72-frame image, and it may be all the luminance I need to collect. Using the 3:1:1:1 "standard LRGB model" what's left to shoot is perhaps an hour and a half of each color channel. I have the new moons of June and July to collect my color frames.

Lesson learned: some smoke at a Bortle 3 may be better than clear sky at a Bortle 4+ site.  Given enough good nights I'd still like to add more luminance and get to 6:1:1:1, but good nights around here seem all too rare.

Satellites Galore (with bonus Trek Humor)

These are the satellite tracks rejected by PixInsight. There are a lot of them in 4.4 hours!

"Go home, Tholians, you're drunk"

That's all for this post. In a couple of weeks the moon will go away again and I'll try to get the color data that will bring this luminance to life. 

First Image from Lac qui Parle State Park

I finally made it to one of the state parks I had found: Lac qui Parle, northwest of Montevideo, Minnesota, and a little under a three hour drive from home. It was only an overnight stay; I was gone from home for less than 22 hours! I had reserved two nights but cancelled the first because of clouds and rain. Had I known what would happen the departure morning I might have driven home in darkness instead of waiting for dawn. I'll get to that later--for now I just want to talk about the park and the image that resulted.

The Park

Camping is in the Upper Campground.  It has quite a few back-ins, a few pull-throughs, and even cabins. There's a modern restroom and most of the spots have power. I opted for a spot with no power, indicated by the red star in the picture below. Horizons are excellent in all directions, so long as you're imaging at a reasonable elevation. There is a light dome from Montevideo about 10.5 miles to the south east, but it only extends upward about 20 degrees. It should only be a factor if you're horizon-scraping in that direction.

The sky is much darker than at MAS's Cherry Grove field. The Milky Way rose while I was imaging, and it was almost as visually spectacular as it is at the Nebraska Star Party.

LqP Upper Campground (N is up). My location is marked by the star.

The nicely modern (flush toilets!) restroom's inside lights activate using motion sensors (good) but the pole lights just outside are always on (bad). They are boxed, but could be a problem for visual observers. The same building also houses showers.

Each pull-in includes a picnic table, fire ring with grill, and one small tree that provides a little shade and is easy to image around. A bonus is that the ground has been leveled. I set up my tripod and was pleased to see that no manual leveling was needed.

If you want to image from LqP, here are few things to know:

• Reservations are required. Although it does look as if you can make same-day reservations at the entrance if you have a phone (be sure to call and confirm that). My phone, using AT&T network, had nice signal strength.
• All state parks enforce "quiet time" from 10 PM to dawn, so no generators may be used during that time.
• The water from the spigot was a little cloudy; I filled a couple of water bottles from it and saw sediment form in each. The water tasted fine but you may wish to bring your own.
• The nearby park office closes at 4 PM, which is also check-in time. If you have reservations you can go directly to your spot. Just bring a copy of your reservation to put on your dash in case a park ranger visits. They didn't bother to check the night I was there.
• Given the wet spring, I thought there would be a lot of mosquitoes. That evening it was almost all gnats and small black flies until around 10 PM, then the gnats went to bed and the mosquitoes started their shift. While they weren't as bad as I anticipated, I was glad I brought along a lot of repellant.
• Directions: Getting to the park from the Metro area is easy. Chances are most of your miles will be on MN 7, a nice highway once out of the Twin Cities. You can bypass Montevideo by turning north onto county 6 eleven miles past Clara City, then 5 miles later head west again on County 13.  At the Lac Qui Parle Recreation Area a right turn onto County 32 will take you to the campground.

The Imaging 

Everything ran flawlessly by itself for the entire session, lasting three hours and 17 minutes from late twilight until the clouds rolled in. That was a first for me!

Every single light frame was great, 89 of 89! Typically I have lost 10 to 20% of my frames. This kind of perfection was also a first for me. I think the ASI 120MM Mini guide camera has solved my guiding problems that were the main cause of lost frames.

NINA's advanced sequencer handled target acquisition and centering, periodic refocusing, and dithering perfectly. 

In the past PHD2 has occasionally squawked about dithering timeouts. Not this time.

Battery talk: The session was powered by my new 50Ah LiFePo4 battery and it said that the session needed only 145 Watt-hours, far less than I expected. Dew control was only used for one hour, though.

It was a great night, even if I had nothing to do!

Now the image. Here is a much reduced version:

vdB 152 and others (click to enlarge)

The full scale image and the usual gory details are at AstroBin. (Attention: AstroBin imagers! This park is in the AstroBin database for you to select.)

I chose this target as a test of the sky, and I'm not disappointed. It's a positive riot of faint nebulae, layers of gas and dust, and nice bright stars. This is why we love dark skies!

The Morning After

Let's just say things could have gone better if the weather forecast of a pleasant morning had been a tad more accurate. Instead I was awoken around 7 AM by thunder and the sound of hail pounding my metal table. Then the wind hit and my two-person tent bowed almost flat on top of me. I got out of it quickly and was greeted to light rain and small hail. The storm that had hit me was receding to the east but another was fast approaching from the west, so I broke camp by tossing everything into the car and started the drive home. The torrential rain resumed and continued to fall on me all the way back; it was not a fun drive.

Luckily something about the way the clouds had popped up during the night prompted me to put most of the gear into the trunk and a tarp securely over the mount; nothing was harmed, although my car has a few minor dents.

And in the "adding insult to injury" department there was this: the storm had not deterred the morning shift mosquitoes and they were ravenous. I think almost all the bites I got during the stay were in that mad 15-minute rush to pack and leave.

But it was worth it.