Going to run some manual focus tests on my wide-field narrowband setup, if I can see the stars tonight. I just want to see if I have the backfocus correct for the Nikon f/2.8 180mm lens. I'm using a 2" Optolong 7nm Ha filter with the Atik 414EX mono CCD camera. No guiding with this tonight, but normally I would have the 130mm guide-scope and ZWOASI120MM-S on top of the aluminum camera/lens ring (ZWO 78mm Holder Ring for ASI Cooled Cameras). My hydrogen-alpha filter is in the AstroShop 2" Filter Drawer System with the tripod foot, which just adds more stability to this setup. You may also notice--if you're familiar with the iOptron CEM25P--that I'm using the short counterweight bar with a single weight. I can carry this whole rig around without taking anything apart.

Posted July 5, 2019

Work-in-progress for Sh 2-132 "Lion's Mane" emission nebula on the border between Cepheus and Lacerta, about 10,000 lightyears away, and over 300 lightyears in diameter. This is why Cepheus is such a wonderful constellation. The Lion's Mane is another giant HII region with ionization partially provided by two Wolf-Rayet stars, WR 152 and WR 153, which have blown out the rings you see in the image. I'm in the middle of capturing data for this. This is a fairly dim object--I only have about half the frames I want for Ha and OIII, and I haven't even started SII capture yet. Here's a bi-color Ha+OIII for the subs I've captured so far. William Optics GT81 APO refractor, ZWO ASI1600MM-Pro mono camera, Astronomik filters, iOptron CEM25P mount. 

Posted July 5, 2019

The "Lobster Claw Nebula" (Sh 2-157), an emission nebula in Cassiopeia, and Sh 2-157a a ring nebula around the Wolf-Rayet star WR 157. I finally captured hydrogen-alpha and oxygen-3 frames for one of my favorite Sharpless catalogue objects. I will come back later in the year to get better OIII frames and an SII set. I didn't get to the underside of Cepheus--or the borderlands between Cepheus and Cassiopeia until 1:30 am, and by then I only had an hour and a half of astronomical night left. This time of year the sky begins brightening at 3:30am, which makes it tough to get to some of these later objects. 

Posted July 3, 2019

I hung around Cepheus and shot several hours of sub-exposures last night, mostly focused on IC 1396, the "Elephant Trunk Nebula", which is easy to make out near the center of the frame. This giant ionized gas region in Cepheus has some amazing dark bands of dust and other interstellar debris, blocking the light of more distant stars. Like there's that little guy on the right I want to call the "Harry Potter casts an Imperio" nebula. Imaging notes: bi-color made up of 48 stacked subs in Ha and OIII, William Optics GT81 APO refractor, ZWO ASI1600MM-Pro mono camera, Astronomik filters, iOptron CEM25P mount.

I also shot RGB subs. Here's the HaRBG:

Posted July 3, 2019

I didn't get a chance to set up the scope last night. As soon as the sun went down it clouded over quickly, so I took the Nikon D750 out and captured a few long exposure shots--in the 8 - 20 second range. I managed to get Ursa Major (Big Dipper) between the clouds. That's Polaris (North Star) on the right. And I wasn't alone out there. The fireflies are out, blinking away.

That's Saturn right there low in the sky, right above the path of the fireflies. Even with the clouds, it was a beautiful summer night out there, maybe because the fireflies were adding their bioluminescent fireworks. Here's a 13 second exposure with two of them flying toward each other.

Posted June 29, 2019

The Rosette Nebula (NGC 2237 et. al.) from my backyard. 28 x 240 secs Ha, 26 x 240 secs OIII. William Optics GT81 APO refractor, ZWO ASI1600MM-Pro mono camera, Astronomik filters, iOptron CEM25P mount, INDI/Ekos/KStars

Posted June 27, 2019

I didn't spend much time on testing last night. The sky was was clear, but seeing was poor. I put the Nikon D750 on the tracker and took a batch of 30 second exposures around 11pm--48 of them, with the tree in the frame. (I cropped some of it out, as well as the edges). Stacked them in DeepSkyStacker and did some processing in PhotoshopCC.

Here's the test in progress, with the Nikon D750 on the tracker and the electronics--arduino and A4988 controller--on the board below, taken with my iPhone. 

Posted June 23, 2019

AstroTrackHD Prototype v4.2 is ready for testing! HD = Harmonic Drive, which is a high-precision, high-torque, zero backlash gear set. See: https://youtu.be/3mWemlMEzFk). The main update with version 4.2 is stepper driver support for interrupt-driven motion, with the ability to set the speed in milliseconds / 1 rotation--"clock mode". This enables me to set the speed equal to one sideral day-with all the gear ratios calculated in. One day in sideral time is 86164.091 seconds, and with a 139:1 ratio gearbox that gives me 619.885 seconds / full rotation. Then on top of this I have the harmonic drive with another 100:1 ratio to calculate in.  I'm going to try this out with a camera tonight!

There's some beautiful weather today, a batch of storm clouds sliding by--north to south--about mile east of us.

Posted June 22, 2019