Here’s a “cool” looking image for all the hot summer days we are having right now! A really amazing object in the southern sky in the constellation Canis Major (the Big Dog), is a big gas bubble cataloged as Sharpless 308. It has a popular (but unofficial) name of the Dolphin Nebula. It’s in the Sharpless catalog because of it’s Hydrogen Beta emissions, but it is especially bright in ionized Oxygen III. This image is about two hours of exposure time through a 3nm Chroma OIII narrowband filter. It’s amazing that we can photographically identify elements this way, but the OIII atoms emit a very specific wavelength of light, and this filter let’s only that wavelength through (well, plus or minus 1.5 nanometers!).
The central star is pre-supernova and is responsible for blowing off all this gas, and is about 4,530 light years from Earth.
Artistically, this was a tough image for me. I took it back in February of 2023 at the Winter Star Party and only now (late July) am I satisfied to publish it. I did take about 1/2 hour of RGB data to give the stars color, but this is basically just an Oxygen emission image of this target. I went back and forth on the coloring. OIII is Cyan (blue/green), but of course the light is far too dim to see. What color is something that’s invisible? I settled on this, and finally even decided I liked the smoky background oxygen that is glowing around/behind the main focus of the image.
Sky-Watcher Esprit 150 refractor
Night Crawler Focuser
Player One Poseidon-M Camera w/Phoenix Filter Wheel
Chroma 3nm OIII narrowband filter
Software Bisque Paramount MYT
30 minutes RGB exposure time
2 Hours OIII exposure time
I’m three months late with this post, but I’ve started writing a monthly feature/blog for SkySafari that is available to their premium subscribers! Each month, I’ll be calling out an astrophotography target for that month and talking a little bit about the object itself and some general tips for astrophotographers. SkySafari is available for both iOS and Android and is one of the most popular (if not the most popular) mobile astronomy apps. You can use it to find or identify objects in the sky, get notifications about astronomical events, and configure your telescope/eyepieces/cameras to plan viewing or imaging sessions. It also controls a great number of telescopes and has a huge database of objects you can search.
This month I’m talking about my favorite target visually, which also makes a pretty nice astrophotography target, M13 (Messier 13), or the great globular cluster in Hercules. Past articles are also available. Last month was the large galaxy M101, and before that the Leo Triplet of Galaxies. It is “Galaxy Season” after all. Each month, I’ll focus on a target that is ready to go at evening astronomical twilight (when it’s dark enough to image deep sky targets). It’s going to be a very long time before I run out of targets to talk about, and I hope you will check it out and enjoy!
If you have SkySafari 7 Pro and already have a subscription to the premium features, just click “Tonight” on the bottom toolbar on your mobile phone or tablet.
The annual Winter Star Party in the Florida Keys is my favorite annual event, always held in February or occasionally in very late January or early March. It’s almost a religious pilgrimage for me, and I’ve only missed once in 20 years since I started attending, and that was due to a death in the family (I was already packed and loaded when I got the worst phone call of my life… but that’s another story).
What’s so special about the Winter Star Party, or WSP? I think it’s the location and of course the people. A star party is after all a social event, and I have met many lifelong friends at WSP. It’s currently held at adjacent girl scout and boy scout campgrounds on “Scout Key”, south of Marathon, but sill 40 miles from Key West. The girl scout side has been ravaged by hurricanes and is a bit more of a primitive camping experience. The boy scout side however is well manicured, has power, a clean and modern bath/shower facility, and even “glamping” tents with AC. Yes, both sides have been hit by the same hurricanes, but the boy scouts have built back. It’s never too late to teach our children that the boys have all the money and get the nicer things… (that’s sarcasm btw… or an indictment, take your pick).
There is light pollution from the keys of course, so it’s not “Okey-Tex” dark skies, but the view to the South is dark, and only with a long exposure (with a camera on a tripod) can you see a small light dome on the horizon… from Havana Cuba! The southern sky is a treat, among my favorites, there’s Omega Centauri, the king of globular clusters, Centaurus A, an amazing irregular galaxy, and if the weather gods show favor — the great Eta Carina nebula will make an appearance, no more than 6 degrees above the ocean’s most southerly view.
The keys are a special place too. I live in Florida, but I live near Orlando and the “attractions” are only an hour away. The Florida Keys are almost like another state entirely. Tropical beaches, the vibrant blues and green of the ocean, tiki huts, and seafood galore. People from all over the world come to my part of Florida on vacation. If you live here, going to the Keys is where we go on vacation. There’s plenty to do in the keys too for your non-astro-nut family members. Key West is also a whole other world in itself. You can rent a boat, go snorkeling, kayaking, fishing, the list is endless.
This past year was my first year in nearly two decades that I did not attend as a vendor representative, and the first held in three years due to cancelations over the Pandemic. The weather was clear, but windy most of the week, and the smart astrophotographers found places in the lee of the wind. I managed to get some good deep sky data, and even did some lunar and solar lucky imaging.
The last clear night was Friday, and the air was still, and heavy with dew, the worst dew event I recall at this event. I had not prepared for this, and my scope dewed over immediately after dark. I put on a dew strap, cranked it up, and used an alcohol wipe to repeatedly remove the moisture. It took about 45 minutes, but finally I was back in business and got my best image data of the week that night. In fact, I hit the celestial jackpot that night.
Early in the morning a friend behind me was “observing” Eta Carina, only about 4 degrees above the horizon. I thought, “well, why not”, and I tried a slew and a single exposure. I expected it to be behind a tree, or below the berm between me and the beach. Surprise! It was not well centered, but it was there, and it was bright! I carefully centered it and found tracking was not that great so close to the horizon, but I could take decent enough 15 second exposures. So, I took 156 of them before a tree did in fact obscure my view! I alternated between red, green, and blue with my monochrome Player One Poseidon-M camera and managed to pull off a decent enough image. One day… I MUST travel south of the Equator to do this target justice.
In the meantime, I’m counting down the weeks until my next “Latitude Adjustment” in February of 2024. See you there? Stop by and say hello!
I plan to do a longer and more thorough report on the Player One Poseidon-M camera at a later date, I’ve only just received it recently and have had a spotty few nights out with it, but I’m pretty impressed so far. I ordered a full set of Chroma filters for it, and my first clear night the only filter that had arrived was a 3nm Ha (Hydrogen Alpha) narrowband filter. The Moon was up and well, Ha is great in the moonlight, and I could not wait to try the new toy out.
Well, who doesn’t shoot M42 when they get a new camera? It’s bright, it’s pretty, and it’s loaded with glowing hydrogen gas — I have a shiny new camera and high quality 3nm hydrogen filter. I wanted to see how much detail I could get out of the trapezium, which is the very bright core of M42, so I experimented to see how long I could go without saturating that region. I was shooting at high conversion gain (HCG), but could go a full minute and still make out the four stars of the trapezium. The screen stretch showed glorious detail already and so I decided one minute was enough.
Orion passes between two trees from my backyard each night, and I only got 104 of these one minute exposures over two nights, but it was quite enough for an impressive image non-the-less of the entire region. I would have liked to get more to reduce the noise in the outer areas, but it is definitely good enough for the internet as is. One minute narrowband subs (oh, this was at f/7 by the way) is pretty impressive, but I have to admit, M42 is a pretty bright target, so I tried a few others also at shorter exposures.
I did some one and two minute exposures on the Rosette and the Tadpoles and stacked equivalent spans of time for each. The one minute stacks did not suffer from what I could tell from a qualitative inspection vs. the stack of two minute subs (both stacks of about half an hour).
I also did 162 x 60 seconds on the Cone nebula region. The screen stretch of the individual subs was very faint on this region, but the stacked result was quite spectacular I thought. The fox fur region is just loaded with detail and subjectively I’d say it’s every bit as good as what I used to do with CCD’s and longer (individual exposures).
I’ve been speaking about the new age of shorter exposures for a while now, but I’ll abbreviate my thesis in that shorter individual exposures are becoming more usable due to camera improvements, but the total integration time for a quality image has only diminished very slightly due to increases in QE (Quantum Efficiency). There is still only so much light coming from astronomical objects, and it still takes hours of total integration time to create a very high quality image. These images look great on the web, but if I were to print them or display higher resolution versions, I’d want a little more integration time to better smoothen them out (from shot noise).
I plan to push on this camera pretty hard, do a lot more experiments (both qualitative and quantitative), write some software, and take some pretty pictures. Stay tuned…
Oh, and if you can, be sure and catch my talk on “The Future of Astrophotography” at the upcoming Winter Star Party, or you can read a reprint of my August 2022 Sky & Telescope article “The Next Big Thing” here.
On the evening of January 5th 2023, the Sun’s angle on the Moon was just right for what I think is a spectacular view of the crater Aristarchus and the Aristarchus plateau. The Plateau is a distinctive squarish region about 200km across with an offset color from the surrounding lunar mare, from which it rises in places 2km above the Oceanus Procellarum. The crater itself is the brightest crater on the Moon and can be spotted naked eye, and will stand out even in Earthshine.
Equally spectacular to me was the far limb showing numerous craters and ridges illuminated by what to them was the rising morning Sun. Often imagers will keep their cameras oriented so that North is up for their astronomical images, and this includes the Moon. I tilted the camera purposely here as I liked the more dramatic view as if flying over the Moon and viewing the landscape personally. There are plenty of atlas’s with topographically accurate orientations to their reference images. I wanted something that made me feel like I was there, because to me at the time, I was — and I snapped a photo to remind me of the visit.
I’m continuing my exploration of “lucky imaging” of the solar system objects, this time with the Sun. A special filter made by DayStar allows only a very narrow wavelength of light through when observing the Sun that is emitted by hydrogen gas. You can see in this image how the gas is swirling around on the Sun, cooler areas (not COOL, just cool-ER) manifesting as sunspots, and of course a few prominences on the edge of the Sun proper. The Suns surface was taken with very short exposures, and the prominences were taken at a slightly longer exposure that causes the surface to just appear solid white. So the two were merged to show the entire view. This is a good example of what we space photography nerds call dynamic range. The full range of brightness in this image can’t be captured by a single exposure length as the camera doesn’t have that much range. Well, truth is, many people do pull that off, and with more practice I may too. For now, two exposures worked well enough for me<g>. Please be sure, this was a very special (and expensive) solar filter. If you turn your Christmas scope to the Sun, you will likely damage the scope, blind yourself, and yes, potentially set something on fire (perhaps your shirt!). Don’t try this at home kiddies, I’m a professional… well, sorta.
For some technical details, the camera (a Player One Apollo Max) is monochrome, or black and white. The image was colorized after the fact for aesthetic reasons. I’ve looked through this filter, and Hydrogen Alpha light is a bright electric pink. It’s only a single wavelength of light, and there’s no point in using a color camera. I matched it in Photoshop… but, man it makes for an ugly picture! Other details… Sky-Watcher USA Esprit 150 refractor with a Televue 4x Powermate to get the focal ratio where it needs to be for the special filter I used (rays of light to the filter need to be pretty direct on and not slanted like at faster focal ratios).
As far as processing goes, I’m getting traction, but I can critique several things about this image. Truth is though, I’ve reworked it a few times already and am ready to apply what I’ve learned now to my next image. Rest assured…. there is ALWAYS a next image.
The evening of December 7th, 2022 was a Full Moon and for many of my US friends the Moon occulted Mars for a short time. In Florida and most of the east coast, it was only a near miss and yes I photographed it like everyone else. But this post is not about that event, but rather the show the Moon was putting on at it’s South Pole. When the Moon is full the Sun is bearing down straight on it, more or less, from our vantage point. The Moon though is a sphere (okay, sphere-ish), and it’s not a smooth sphere, it has bumps, valleys, hills, etc. We often love observing the lunar terminator when these features are in stark relief, but still we are seeing these features from directly overhead. If only we could fly to the Moon, and look at them from a low elevation to see them in the distance rising from the lunar surface. Well… we can!
This is exactly the view we have when the Sun is grazing along the edges of the Moon. On the night of the occultation, the southern edge was putting on quite a show and I just had to take some video for later processing (a technique we call “Lucky Imaging“).
The image below was taken through a Sky-Watcher 180mm Maksutov-Cassegrain telescope and a Player One Neptune C II high speed camera. Many thousands of frames were taken, but the atmosphere is turbulent, so a computer program helps search through all the individual frames to find the ones with the most stillness to them. They are combined to make a clean smooth image, and then I apply a little sharpening to clear up any blur remaining. I also rotated the original image 180 degrees to give the sensation of flying over the Moon rather than under it.
The conditions were excellent, so I decided to try doubling the magnification with a 2x Televue Powermate. This brought my total focal length to 5,500mm and with my cameras small pixels, an astonishing 0.11 arc-seconds per pixel resolution. For most deep sky objects (galaxies and nebula) you can only achieve this much resolution/magnification with long exposures by putting your telescope in space where there is no atmosphere. Doing this from Earth requires very fast frame rates to capture the stillness, and a great number of frames to choose from. That’s why we call it LUCKY imaging!
This second image is the left most area from the image above, but taken at twice the focal length. The camera rotation doesn’t match if you can forgive me for that, but it still captures the feeling of really “being there”, at least it does to me.
Finally, for the selenophiles out there (of whom I count myself), I’ve also labeled some of the more prominent craters in this image. Who say’s the full Moon isn’t interesting to photograph?!? Definitely not me.
Read with Sean Connery’s accident, “You call this astrophotography?”
Happens to me all the time… on the space coast. I am quite fortunate to live an hour away from the Kennedy Space Center, and I can see most launches from my yard when the weather is good. Sometimes though, you just have to drive over, and not since the last time I drove over for a night Shuttle launch have I seen something so spectacular as the launch of Artemis 1. The Moon has always been my first love of the celestial realm, and since I was a boy I dreamt of walking there one day. I still remember my mother getting me out of bed just shy of four years old to see the broadcast of Armstrong on the Moon. My father acted like it was the greatest thing ever, and it left an impression on me to this day. I plan to be there too when mankind (and this time a more diverse crew) again launches to the Moon. Godspeed Artemis 1, the precursor to our return to crewed flights to the Moon!!
Oh… and I got an extra bonus. I caught what I’m pretty sure is a NASA helicopter monitoring the launch, or it’s silhouette in the bring light of the launch. It had no running lights, but it’s as plan as day when you spot it in this photo! It’s astonishing how recently even a helicopter would be considered a fantasy, and here we are going to the Moon AGAIN!
Last week I had some “work” (I often do imaging research and development scope side) to do and the night before I was getting a new scope and mount lined up and tested ahead of time to save a couple of hours at the beginning of the night “of the tests”. The last thing I did was slew (point the telescope) to Jupiter. There it was, right in the center of a DSLR I had on the back as a simple camera that would do the job for alignment testing. Hmmm, I thought, I have to take that camera off anyway, maybe I should pop in an eyepiece and at least look at Jupiter as it is so well place at the moment. It of course was spectacular as always but I could not believe my luck — not only was the Great Red Spot visible, but the moon (natural satellite actually) Io was nearby and casting a shadow on the Jovian clouds, near the Great Red Spot! Basically, this is a solar eclipse on another planet, caught from Earth! 10 minutes before, I was looking forward to going to bed early, and now I’m digging out tele-extenders, spacers, etc and putting a high speed camera (Player One Neptune C-II) on the back of the telescope in place of the eyepiece. “Lucky Imaging” is a technique where we take many thousands of high speed images (this only works with bright targets like the Moon, Sun, and Planets) and then let the computer pick out just a few of the sharpest images taken during moments of stillness in the turbulent atmosphere.
In this case, I was lucky in more way than one, and I’ll take the win!
“From dust you are made, and to dust you shall return.”
The universe is a dirty place. I love this wide field image that prominently displays the great Orion Nebula (and nearby Running Man), a place of star birth and glowing gas on one side, and the dirty brown rusty colored dust of stars long dead who have given up their nuclear fused materials as the seeds of new stars and planets yet to be. The whole circle of life of the cosmos is on display here!
Tech details: Astro-Physics Stowaway 92mm refractor on a Software Bisque Paramount MX+, QHY 128C Pro one shot color camera. There’s 6.5 hours of exposure time gathered over three nights from my dark sky site in Okeechobee county Florida.