How about a little Voldemort with your Astronomy? Here's Barnard 104, the Fish Hook Nebula (backward checkmark nebula was already taken?), just left of the star beta Scuti in the constellation Scutum--along with several other absorption nebulae in the Barnard Catalogue, 113, 111, 110, 107, and B106. (See the image below). These are the dark cloudy regions across the middle, which stand out against the glow of a billion stars in this area of the Milky Way Galaxy. (Okay, I'm being a bit deceptive with the drama there. It's probably more like 5 or 10 billion). Oh, and let's not forget NGC 6704, the open star cluster toward the bottom in the center. A note on the "Barnard Catalogue", which is what I've always called it: I just found out the official name for it is the very Harry Potter sounding, Barnard Catalogue of Dark Markings in the Sky. Go home, Death Eaters! The star gazing geeks got here first! (ZWO ASI071MC cooled CMOS camera at -10°C, iOptron CEM25P EQ mount, William Optics ZenithStar 61 f/5.9, 12 x 120 sec. sub exposures, stacked in DSS. Location: Stratham, New Hampshire, US. Bortle 4).
So, all in all, a successful night of astronomy stuff, even with the clouds rolling in around 2 am. Here are a couple more wide-field shots from the session, the Eagle Nebula and the Sadr Region--the diffuse nebula (IC 1318) around gamma Cygni, also called Sadr (center star in the constellation Cygnus).
I spent a few hours last night dialing in the Orion "TOAG" or Thin Off-Axis Guider, which I bought a couple years ago, but have never been able to get working properly. I've tried seven or eight times, added it to my imaging train a couple times a year, attempting to get things working without success. Well, I went at it again last night, and you know what? It came together. I still have some weirdness to tinker with--to work out, but for the first time I wasn't guiding with a separate scope. I was guiding at the same focal length as the ZS61 using a pick-off prism that directs a portion of the field of view up into the guide camera. Here's the setup I used last night to dial-in the distance between the primary camera and guide camera, and then bring everything into focus. I ended up with some pretty cool shots, but my main purpose was to get Off-Axis Guiding (OAG) adjusted and working--and that was with me slewing around the sky to clear areas between banks of clouds to find some halfway interesting targets. In this setup I'm using my trusty ZWO ASI120MM-S for guiding, and the ZWO ASI071MC cooled color camera for the primary. The goal here is to be able to guide (track the motion of the earth against the star field to a very fine degree, and make small incremental adjustments to the EQ mount) so that I can take long exposures without worrying about the external guidescope issues I know all of you care deeply about, like field rotation and differential motion between a guide scope and imaging telescope. I have been able to take 20 minute exposures with a guidescope and camera, but the stars are not as sharp as I would like--think pressing down the button of your camera and holding the shutter open for 20 or 30 minutes and have everything in the field of view remain in sharp focus. That's essentially what the guiding system accomplishes, taking continuous images of the stars and feeding them to some pretty sophisticated software that controls the motion of the equatorial mount (that's the white z-shaped device with the black boxes on which the telescope is fastened and balanced).
The Crescent Nebula (NGC 6888) with two channels, hydrogen-alpha and oxygen-three. 4 x 1200 second exposures for the Ha (mostly red channel), and 10 x 600 second exp. for the OIII (mostly blue channel). I didn't get nearly enough of the blue halo around the Crescent as I would have liked. I'll probably need to go to 20-minute exposures in OIII next time--or more 10 minute ones.
It's winter and that's when Orion is arguably the main attraction in northern hemisphere skies. HaRGB of the Horsehead Nebula (Barnard 33) along with the reflection nebula NGC 2023 (below and left), part of a whole neighborhood of nebulosity around the leftmost star in Orion's Belt, the blue supergiant Alnitak. (I kept Alnitak out of frame, but it would off to the left with a wider field of view). The Horsehead is an absorption (or dark) nebula about 1500 lightyears from Earth, and shows up so prominently because it's blocking most of the starlight behind it. (10 x 600 second Ha frames, 10 x 240 second RGB frames, 24 dark cal frames taken with an Atik414Ex mono CCD, William Optics GT-81 + 0.8x Field Flattener/Reducer f/4.7, iOptron CEM25P EQ mount, Astronomik 12nm Ha filter, Baader RGB filters, WO 50mm guide scope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control. Location: Stratham, New Hampshire, US. ~Bortle 4)
The full FOV for this shot:
The temps are nice--downright warm compared to what we've been hit with over the last couple weeks. The clouds are the problem. They gave me two hours of clear skies, and I spent them taking a batch of five minute exposures of M42, the Orion Nebula. (Atik414Ex mono CCD, William Optics GT-81 + 0.8x Field Flattener/Reducer f/4.7, iOptron CEM25P EQ mount, Astronomik 12nm Ha filter, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control).
I took several hours of hydrogen-alpha, oxygen 3, sulfur 2, and RGB images last night. Here's the color version of the Rosette Nebula (nebular region) with OIII and SII frames added to a bunch of Ha frames I shot at the beginning of the month.
Okay, this new astro setup worked well (see yesterday's post). I just bolted on the mount, did a quick polar alignment, and I was taking beautiful twenty-minute exposures of NGC 1499 (California Nebula). I shot some hydrogen-alpha of the California while waiting for the Rosette Nebular region to come into view.
I have been on this automated portable astrophotography path for a while; it's been a slow but continuous process of remote controlling my entire astro imaging rig from anywhere. I set it up, and as long as there's power and wifi, I'm good to go. This latest iteration, making the whole rig portable, is going to make things easier on those nights when I know I'll only have two hours of clear skies. Before now I wouldn't even think about setting up because that could eat up an hour alone. (Atik414Ex mono CCD, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control)
Four stacked 1200-second frames of NGC 1499 with the 12nm Astronomik Ha filter:
A couple test Ha frames of Lower's Nebula (SH 2-261) in the constellation Orion. I only took two exposures of Lower's Nebula while waiting for the Rosette Nebula to rise, and it reminded me of a scene in the movie Roxanne with Steve Martin (CD Bales) and Daryl Hannah (Roxanne):
C.D. Bales: You must know about M31.
C.D. Bales: Now, see, I like it when they give astronomical objects names, you know, like "Andromeda" and "Saturn" and "Sea of Tranquility." This whole numbering thing is just too boring for us civilians.
Roxanne: Do you know how many objects are up there?
C.D. Bales: Well, I know it's over fifty.
That's the problem when you're a constellation like Orion, with a nebula so massive and bright you can see it clearly without a telescope (M42), or you possess dark nebular structures famously shaped like animals (Horsehead nebula, Barnard 33). You get overlooked if you're not a superstar or supernova remnant or "The Great" Orion Nebula. Yeah, that's Lower's Nebula (SH 2-261), which I'm sorry to say, I had never heard of before last night. Unfortunately that's probably because Lower's Nebula isn't the buckle on Orion's Belt. It isn't even hanging off of Orion's famous belt. It is literally out on a distant arm of the constellation--yes, Orion has one arm raised, far away from the Belt, and the famous stars like Betelgeuse, Bellatrix, and Rigel, and that's where you'll find this obscure cloud of hydrogen that doesn't even have a wikipedia page (In English. I found an Italian page for SH2-261. Nicely done, Italy.)
(Subframe info: one 600-second exposure and one 1200-second exposure stacked in DSS, no calibration frames, Atik414Ex mono CCD running at -10C, Astronomik 12nm Ha filter, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control)
We were very close to a full moon last night, so my astro imaging options were limited to narrowband. I spent most of the night with Hydrogen-alpha, an inexpensive 12nm Astronomik filter, but as you can see, able to bring out some fantastic contrast, depth, and details throughout this region of interstellar ionized hydrogen. (This is the filter I currently have in the 1.25" wheel. My Baader 6nm Ha is in the 2" filter wheel)
The "Rosette Nebula" is a cluster of nebulosity that includes NGC 2237, NGC 2238, NGC 2244, NGC 2239, NGC 2246 and more. The Rosette is a bright mag 9 area of the sky about 1.3° across in the constellation Monoceros. (subframe info: 28 600 second exposures in hydrogen-alpha, no calibration frames, Atik414Ex mono CCD running at -10C, Astronomik 12nm Ha filter, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control). https://www.astrobin.com/324406/
One of many reasons I love the Atik 414EX is how clean (free of noise) the light frames are when you cool the sensor down to -10C or below. I didn't shoot dark frames, or any other calibration frames last night, and didn't use any from my library when stacking.
My last target of the night: center portion of IC 2177, the "Seagull Nebula" in the constellation Monoceros. There's noise that showed up during stretching, but this one of IC 2177 is just 4 stacked Ha frames, each 600 seconds.
Here's a screenshot of Ekos and KStars, in the process of capturing 600 seconds of photons landing in my backyard from the Rosette Nebula. This is pretty much what I see--the tools I work with--when remotely controlling the mount, telescope, cameras, targeting, focusing, plate solving, and more. And that's what a single 600-second frame looks like. With stacking I'm obviously getting a lot more signal to noise.
IC 405--"Flaming Star Nebula" in the constellation Auriga, centered on the mag. +6 star AE Aurigae. It's relatively close to us, at about 1,500 light-years. This set of subframes covers the center of the fairly large nebula, which measures 37 x 19 arcminutes. (6 x 1200 second subs in Ha, O3, S2, taken with my current main setup: Atik414Ex mono CCD, William Optics GT-81, CEM25P EQ mount, WO 50mm guidescope with ZWO ASI120S-MM guide cam, INDI/KStars/Ekos observatory control).