It never ceases to amaze me what can now be done with a modern astro-imaging camera and a 3″ refractor! Also, it blows my mind that such faint details can be recorded during the full, or near-full Moon, and this is down to the use of narrowband filters.
This is an image of the NGC2264 region, also known as The Christmas Tree Cluster. There are several objects contained within this region such as The Cone Nebula and The Fox Fur Nebula and I think it’s clear which is which in this image. Additionally, there is a strange comet-like object in the upper-left quadrant which is called Hubble’s Variable Nebula. This is a fan-shaped cloud of gas and dust which is illuminated by the star R Monocerotis (R Mon), the bright star at the bottom end of the nebula. Dense condensations of dust near the star cast shadows out into the nebula, and as they move the illumination changes, giving rise to the variations first noted by Hubble.
This region of the sky is in the constellation called Monoceros (Unicorn in Greek) which is to the left of Orion.
As always, click on the image to see a bigger and better version about 6000 pixels across. I’ll add some details about how I took it below the image.
You can see the equipment I used to take this image here. Also, I talk about the narrowband filter I used here. I took about 100 exposures over two nights in January 2022, around the time of the full Moon. Each exposure was 10 minutes long. I used the amazing PixInsight software package to calibrate and assemble the images into the final result you see here.
The Pleiades, M45 in Taurus is the closest Messier object in the sky and is easily visible to the naked eye. What is not visible is the beautiful nebulosity around the young, hot, blue stars that make up this open star cluster. However, long exposure astrophotography reveals the nebulosity and this image is an integration of 174, five minute exposures making a total exposure time of 14.5 hours. To see details of the telescope setup that I used to take this image from my home click here.
Click on the image below to see the full resolution version.
I’m very excited about this! I have finally taken the plunge and now have (or will have in early November) a remote imaging rig in Southern Spain. It is located at the PixelSkies remote hosting facility near Castilléjar in the province of Granada, Andalucia.
The imaging rig itself was originally built in 2020 and owned by First Light Optics, and it was used to capture images for a monthly image processing competition. I learned from Ian King that it was for sale and I couldn’t resist the opportunity to buy this, already proven, setup. Normally, one has to buy the kit and ship it out to the hosting location, all of which takes time, planning and money.
Here’s a picture of the whole system located in one of the roll-off roof sheds. More details and pictures are below.
The telescope itself is a StellaMira 104mm ED2 Triplet f/6.25 APO Refractor (with field flattener) and this rides on an amazing 10Micron GM 1000 HPS mount which has absolute encoders. The detector is a Starlight XPress TRIUS PRO 694 mono CCD camera which has 2750×2200 pixels in a medium format Sony chip. The resulting field of view is 66 x 53 arcminutes at a resolution of 1.44 arcseconds per pixel. To give an idea of what this means, the Moon would fit twice across the resulting images. The picture below shows the CCD camera connected to the telescope.
Also visible in the picture above is the 7-position filter wheel containing Optolong 1.25″ filters. The filters are the usual set of LRGB filters and the three 7nm narrowband filters for HA, OIII and SII. Notice also the Off-Axis Guider (OAG) with the Starlight Xpress LoadStar V2 guide camera siticking out to the right of the filter wheel. The pick-off prism for the OAG is in front of the filters so that unfiltered light always hits the CCD sensor of the LoadStar.
The picture below shows the 10Micron mount more clearly and also the Lakeside Astro motorised focuser. It is, of course, vital to be able to accurately focus remotely and the focus point will vary with temperature during the night, and is also different for each filter.
Also shown above is the mounting plate on top of the telescope cradles which has the red Hitec Astro Mount Hub Pro V4 control box. This has a full USB hub along with software controllable power ports and dew heater controller. This hub allows the cabling to be kept shorter and neater. Without a control hub like this, all the cabling would have to travel down to the PC on the floor and would create potential cable snagging issues as the telescope slews around. Here is a close up of the hub:
Another fantastic feature of this setup is the built-on flat panel. This Alnitak Flip-Flat will allow me to take my own flat-field images without asking anyone to arrange for a flat panel to be balanced on the telescope. This device can be seen at the front end of the telescope and it also acts as a lid for the telescope to prevent dust getting on to the objective lens. The opening and closing of the panel is software controlled as is the brightness of the flat panel. During cloudy nights I can also take bias and dark frames when the panel is in the closed position, but turned off. See the picture below which also shows the wide angle video camera (the red device below the flip-flat). This sensitive camera provides a wide view of the sky, useful for spotting clouds or generally admiring the constellations and the Milky Way.
Mounted on the mount pillar is a small Astromi.ch MBox device. This is a small, self-contained weather sensing device that delivers barometric pressure, temperature, humidity and dew point information with high accuracy. There are other bits and pieces (including the main Windows 10 control PC), but I have described the main components.
In due course I’ll share more information about how I get on with this fantastic system, and hopefully, lots of great images from this dark-sky site.
Finally, watch this video to see the system being assembled a year or so ago.
Messier 31, the great galaxy in the constellation of Andromeda is one of the most photographed night-sky objects of all, probably second only to the Orion Nebula. Every few years I get an itch to image it again. Most astro-photographers like to revisit old targets once in a while, and this often happens when new telescopes and cameras have been purchased, and this is the reason why I’m having another go at this beautiful object. I showed off my new kit in my previous post.
It is often said of M31 that it is the furthest away object that can be seen with the naked eye. This is an amazing thing when you think about it! This galaxy is about 2.5 million light years away and it is the nearest large galaxy to our own Milky Way galaxy which is not too different in structure from M31 itself. In a dark, moonless sky, M31 looks like a fuzzy blob to the naked eye. Some people say they can also detect another nearby galaxy called M33 – The Triangulum Galaxy with the naked eye. I personally can’t see M33, but it is further away from us than M31 at around 2.75 million light years, so M33 really does represent the furthest thing anyone can see without optical aid of any kind. I’ve asked a lot of people if they can see M33 in a good, dark sky in the UK, but I’ve never found anyone who can, so I’m happy that those photons that left the Andromeda Galaxy when Homo habilis first walked the Earth, enter my eye and are detected by my retina represent the most ancient particles of light that can ever stimulate the human consciousness.
Here is my latest image of M31. Click on the image below to view a much larger version (4000 pixels across). Next, I will describe some more details of how this image was acquired and processed.
Firstly, what are we looking at here? The first thing to realise is that we are viewing this spiral galaxy from an angle of about 45 degrees. If we could fly over the galaxy and look directly down on it, we would see a vast spiral shape. Another thing to understand is that all of the distinct, bright stars in the image are all relatively close-by stars in our own Milky Way – in other words we are looking through a ‘curtain’ of nearby stars to see outside our own galaxy. We should understand that galaxies are vast islands of stars, separated by huge distances of near-empty space. The Andromeda Galaxy contains about a trillion stars (that’s a million, million stars) which is about twice the number in our own Milky Way galaxy. So, you are looking at all of these trillion stars in this image which are too far away to see them individually, so they glow like a huge mass.
What else can we see here? Well, you will see the dark regions in the galaxy. These are huge lanes of cosmic dust which are obscuring the light from stars behind them. Also, if you zoom in to the big image you will see the disk of red regions that glow around the galaxy. Here’s a zoomed in region that shows the red regions nicely. Each of these red areas shines be the light of Hydrogen-Alpha. All of them would be seen as nebulae to any inhabitants of planets orbiting the stars in M31 and any of them could be the equivalent of, say, the Orion Nebula that we see locally here in our region of the Milky Way.
Lastly, there is a bright elliptical blob showing below M31 in the main image. This is a dwarf elliptical galaxy called M110 which is a satellite to M31 itself. We have similar objects associated with the Milky way and they are known as the large and small Magellanic Clouds.
So, how did I create this image? I used the telescope and camera system I showed in my previous post. Over four clear nights in October 2021, I took lots of long exposure photographs of M31. The telescope was guided very accurately by the separate guide scope that was checking the guiding accuracy every 2 seconds throughout the whole time, and instructed the mount to make tiny corrections to keep the galaxy perfectly still on the chip of the sensitive camera. Eventually I had about 22 hours of exposures stored on my imaging computer. By the time I weeded out the poorer frames, I had 10 hours of data from my broadband luminance filter, and about 7 hours of data from my narrowband filter.
The narrowband filter I used was the 2″ Optolong L-Extreme filter. This passes light from both H-Alpha and Oxygen-III sources, both with a passband of 7nm wide. In this image I only wanted the H-Alpha data, so I extracted the red channel from the narrowband images and threw away the green and blue which shared the OIII signal. Then I merged the H-Alpha signal with the red channel from the broadband RGB images. This enhanced the red emission nebulae in M31 beautifully.
I’ll write a more detailed blog about my process next…
Since the early Summer of 2021 I have been building up a new deep-sky imaging setup based around the beautiful and venerable Takahashi FSQ-85EDX Refracting telescope. I’ve always wanted a ‘Tak’ and decided to go for this model known ad the ‘Baby-Q’. The optics are glorious and the focuser is incredibly rugged and can carry heavy cameras and filter wheels.
The idea, eventually, is to turn this setup into a fully robotic system which will be mounted low to the ground and housed in a simple box-like structure with a sliding roof. For now, I’m testing out the system to see how it performs.
Here is a small gallery of photos of the current system. I will add more details about the components below.
Here’s a list of the main components that you can see in the above photos:
Telescope: Takahashi FSQ-85EDX F/5.3 Apochromatic Refractor with 1.01x field flattener.
Mount: Skywatcher AZ-EQ6 Pro
Camera: QHY268C cooled CMOS camera (one-shot colour, full 16-bit)
Filter Wheel: Starlight Xpress 5 x 2″ filter wheel
Guide Scope: ZWO 60mm. Focal length is 280mm, F/4.67
Guide Camera: ZWO ASI290MM Mini mono
Auto Focuser: Pegasus Astro FocusCube2
Power, Dew Heater and USB Hub: Pegasus Ultimate Powerbox V2
Dew Heater bands on both scopes
Windows Computer: Beelink Mini PC (in the plastic box on the ground running N.I.N.A.)
If you look at the photos with all the cabling, you will see a plastic box on the ground below the mount. This contains a ‘headless’ mini PC running Windows 10. Think of an Intel NUC and you will get the idea, but this is a Beelink with an Intel i5 CPU which comes cheaper than a NUC. This computer has all of the software installed to control the rig. I’m using the free N.I.N.A. software here and the little PC is connected to the wireless router I have in my dome just a few feet away. This allows me to use remote desktop from the comfort of my dome, office or house.
The thing that really was a ‘game-changer’ for me is the Pegasus Powerbox which is mounted just below the lens of the main scope. This provides all of the 12-volt power ports I need to run the various bits of kit and also has a USB hub with 6 ports. Additionally it can power and control the heat of three heater bands and can detect the dew-point so that it can intelligently adjust the power to the bands to keep the lenses free from dew. Because nearly everything connects to this hub, there are only two cables that need to be connected to the big plastic box on the ground. One is the 12V power to the hub and the other is the USB3 port to the Beelink mini PC.
I run the amazing free N.I.N.A (Nightime Imaging ‘N’ Astronomy) software on the mini PC and the recently added Advanced Scheduler is amazing allowing me to power up the system before dark and set up various targets to image during the night. The system will do everything such as cooling the camera, auto-focusing, slewing and centring targets, flipping across the meridian and shutting down at dawn. It can also deal with re-focusing during the night if the focus drifts and re-centring after a cloudy spell.
Assuming I get some clear nights over the Autumn months, I will hopefully be posting some new images soon.