The dust and hydrogen gas of NGC 2327 "Parrot Nebula" and IC 2177 "Seagull Nebula" span 100 lightyears between the constellations Monoceros and Canis Majoris. This is another one from last night (New Years Day). After shooting the Flaming Star Nebula for several hours, I dropped down to IC 2177 for the remaining clear skies (up to around 1am). Neither of these targets are strong--or have anything showing up--in the oxygen bandpass. I ended up cutting the OIII frames and going with bi-color Ha and SII. Exposures: 28 x 300 seconds of Ha, 26 x 360 seconds of SII. Equipment: William Optics GT81 APO refractor, ZWO ASI1600MM-Pro monochrome 16MP camera (unity gain 139/21), Astronomik filters, iOptron CEM25P mount, INDI/Ekos/KStars running in Stellarmate/Raspberry Pi 3b+
The star at the core of this nebula is the "Flaming Star", AE Aurigae, in the constellation Auriga (The Charioteer), and all the surrounding dust and clouds of hydrogen is called the Flaming Star Nebula (IC 405). This emission nebula is around 1500 lightyears away and it's fairly large, about 5 lightyears across (roughly 47 trillion kilometers or 30 trillion miles across).
What's interesting is that even though AE Auriga is lighting up the nebula, it was not formed there, but rather is a "runaway star" that was probably ejected several million years ago from the star formation furnace in the core of the Orion Nebula. The star is moving quickly through the nebula, producing a violent bow shock with a wave of high energy electromagnetic radiation.
Frames: 23 x 300 seconds of Ha, 5 x 300 seconds of OIII (I was not picking up oxygen at all!), and 20 x 360 seconds of SII. Equipment: William Optics GT81 APO refractor, ZWO ASI1600MM-Pro monochrome camera (unity gain 139/21), Astronomik filters, iOptron CEM25P mount, INDI/Ekos/KStars running in Stellarmate/Raspberry Pi 3b+.
I put together a batch of images from my astrophotography sessions over the last year. This isn't in order, because a wanted a nice mix of color, narrowband, hydrogen-alpha only, wide-field, moon shots, along with some of my astro gear setups for some of these sessions.
NGC 1499, California Nebula in bi-color narrowband hydrogen-alpha and sulfur 2. I captured this data on the 25th, but didn't have time to capture oxygen 3 frames with high clouds moving in and the moon rising. Even so, I like the way this turned out with the two bandpasses, almost fluorescent. NGC 1499 is about 1000 lightyears away, and if you haven't guessed, it's called "California Nebula" because if you flip this image 90 degrees counterclockwise it looks like the state.
Wide-field of M42, the Orion Nebula--and it's amazing how cloudy and dusty the whole area is. I spent half the night adjusting things--focus distance, off-axis guider spacing, but managed to capture M42 and the surrounding region (two sets of subs: 21 x 300 second, and 20 x 20 second for the bright Nebula core and Trapezium). Calibration frames: 20 Dark and 20 Bias, No flat frames. I shot these with the ZWO ASI1600MM-Pro monochrome camera, Astronomik 12nm Ha filter, William Optics ZS61 APO, iOptron CEM25P mount.
I also managed to capture a dozen frames of the California Nebula:
This one of the Heart Nebula (IC 1805) in Cassiopeia is comprised of 27 x 600 second exposures, taken over several nights, with the ZWO ASI071MC and the William Optics GT81 APO refractor, no filters, no calibration frames, stacked in DSS, processed in PSCC 2019. This is pretty impressive for a color camera when you consider the Heart is mostly made up of glowing ionized hydrogen gas and dust (perfect for narrowband imaging), and it's a relatively dim object--with the exception of NGC 896, the bright "Fish Head Nebula" at the bottom.
Soulful Friday--more importantly it was a cloudless Friday on the 10th. I'm going to have to do a mosaic for the whole thing, but for now here's the southern end of IC 1848, the "Soul Nebula" in Ha and OIII (Soul is also identified as Westerhout 5 and Sh 2-199). IC 1848 is in the constellation Cassiopeia, and what you see here is a bit more than half the 100 lightyears in length of the whole nebula--so what is that, something like 588 quadrillion miles from top to bottom? At 6,500 light-years away, that will make a nice four panel mosaic. (Notes: 40 x 240 seconds in Ha, 28 x 600 sec. in OIII. Atik 414EX mono CCD, Astronomik 12nm Ha, OIII filters, William Optics ZS61 + WO Flat F6A f/4.7, iOptron CEM25P EQ mount, Orion OAG + ZWO ASI120MM-Mini guide cam, Stellarmate OS (INDI/KStars/Ekos) running on Raspberry Pi 3b+)
This is the first time I've captured any subs of NGC 2264, the Cone Nebula, about 2600 light-years away (800 Parsecs) in the constellation Monoceros. NGC 2264 includes several identified objects, including the Cone Nebula, Fox Fur Nebula and a massive variable star system, the Christmas Tree Cluster at its core. (Notes: 61 x 300 seconds in Ha, 48 x 300 sec. in OIII. Atik 414EX mono CCD, Astronomik 12nm Ha, OIII filters, William Optics ZS61 + WO Flat F6A f/4.7, CEM25P EQ mount, Orion OAG + ZWO ASI120MM-Mini guide cam, Stellarmate OS (INDI/KStars/Ekos) running on Raspberry Pi 3b+)
Near-Infrared: I also captured 40 frames of M78, a reflection nebula in the constellation Orion. I captured 20 of each in Ha (~656nm) and infrared with the 685nm longpass filter to see what showed up, and was surprised by what I could see in the unstretched subs. There really is a lot going on at the red end of the spectrum--and beyond, and I combined both of them in this shot, divided evenly across RGB (R=Ha, G=50%Ha/50%IR, B=IR). The plan is to come back with a set of color frames and see if I can combine the whole set.
I took some pics of my narrowband setup for this imaging run, before nightfall and in the middle of shooting frames for the Cone Nebula just before Meridian Flip.
Here's a screenshot of Ekos and KStars running, with the guiding tab opened. It was pretty windy, so an RMS" of 0.58 is great, but overall my guiding has improved since going to an Off-Axis Guider. I'm now using the Orion Thin OAG on both trains--color and narrowband, and the difference is noticeable. It took some time to dial sensor and focus distances in, but results are clear, and I just don't think I'll ever go back to a guide scope.
First shot of the season in the constellation Orion! I set up the AstroTech RC scope (6"/152mm aperture f/9) with my narrowband imaging train, Atik 414EX, ZWO filter wheel with Clear, Ha, OIII, SII & IR685, William Optics 0.8x field flattener/reducer that brings the AT6RC to f/7.2 at 1080mm focal length. With the Atik's 6.45μ pixels this has my resolution at 1.23 arcseconds per pixel, and a field of view of 0.48° x 0.36°.
Here are some shots of my set up last night, before nightfall, and in the middle of the narrowband run with 600-second exposures.
The 1000mm+ focal length did get me wonderfully close to the Horsehead Nebula (B33) and the reflection nebula NGC 2023 (bottom left) in the constellation Orion. This is what 46 stacked 600 second hydrogen-alpha frames will get you if you stretch things a bit too much and don't use any calibration frames. That would reduce the noise/graininess somewhat. Anyway, pretty happy with this. (46 x 600 second exposures in Ha, Atik 414EX mono CCD at -10C, Astronomik 12nm Ha filter, AstroTech AT6RC f/9 Ritchey-Chrétien + WO Flat6A f/7.2, iOptron CEM25P EQ mount, Orion OAG + ZWO ASI120MM-Mini guide cam, Stellarmate OS (INDI/KStars/Ekos) running on Raspberry Pi 3b+. Stacked in DSS, processed in Photoshop CC 2019).
I stretched the hell out of this stack of 46 x 600 second subs, mainly to see what the data would show if I went out of my way to bring out the details. I also didn't use dark frames with this--so that's worth a try. The Atik 414EX at -10C or cooler is very clean, though. I usually don't gain a lot with calibration frames, but in this case even a little will improve the noisiness.
I don't use the AT6RC scope that much, mostly because when paired with the cameras I have the resolution is oversampled crap. The Atik is the only one that's right in there at 1.23 arcseconds/pixel, and that's with the 0.8x field flattener/reducer.
Another point (or set of points) I would like to make is the Astro-Tech 6" f/9 Ritchey-Chrétien is a $400 scope, and I'm pretty impressed with the light and contrast it managed to pull out of the night sky. Some of the credit certainly goes to the Atik CCD, which really is an amazing little camera. The sub-$1000 iOptron CEM25P has no problem with long exposure times. Along with the $129 12nm Astronomik Ha filter, this is a very inexpensive narrowband setup. The point being you don't need to spend a raft-load of cash to start capturing those beautiful HII regions, supernova remnants, and other wonders in the night sky.
My tips for the iOptron CEM25P--or what I've learned over the last two years: For narrowband, I normally shoot 5, 10 or 20 minute subs depending on the brightness of the target, and the iOptron has no problem. However, there are a few steps I go through in order to get very long exposures from this mount. 1) a solid foundation--solid tripod or better. I don't have a concrete or steel pier, but I do have a treated 4x4 solidly in the ground, and it doesn't move. 2) More counterweights, closer to the center of balance. I try to use more weight, and keep them as close to the top of the counterweight shaft as possible. I know it's tempting to use fewer weights farther out, but trust me on this--and don't worry about the bushings that carry all the weight. They can handle far more than you'll ever bolt on. It's minor, but it does smooth out tiny movements the scope has to make--so improved guiding. 3) Balance, balance, balance. You want a perfectly balanced scope and equipment. Don't bias weight to one side; don't get your gear "close enough". If you'll permit me to anthropomorphize the CEM25P for a moment, you want the mount and motors to think they're moving nothing at all, and for that you'll need to balance the shit out of your payload. I use small 100g camera gimbal weights to even the load--balance is that important. (https://www.amazon.com/gp/product/B0797S81HR)
Okay, I also took some subs of the Triangulum Galaxy core (M33) while setting up and getting into focus--testing out shooting in 2x2 binning, which reduces the resolution by half.