NGC 2264 - The Christmas Tree Cluster & Cone Nebula...

Object: NGC 2264
Type: Open Cluster & Emission Nebulae
Constellation: Monoceros
Distance: 2400 light years

Date: 31 January, 06 & 10 February 2018
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, NEQ6 mount, guiding with Lodestar X2/PHD

Subframes: 70 x 300s H-alpha, 20 x 300s RGB, no darks (hot pixel removal in Astroart instead).

Subframes were stacked in Astroart, the outputs converted to TIF files and then colour-composited in PaintShop Pro. I gathered the colour data on the third night, but I quite liked the mono H-alpha image on its own, so I posted that as well (below).

The colour data was a bit of a pig to process with the software I have.  First of all it became apparent that 300 second subs in H-alpha probably weren't long enough.  I had to stretch the resultant stack quite a way to get any decent detail, which introduced more noise than I really wanted. Then the blue colour stack turned out to be a slightly different size to the others, despite all being full frame without any need to resize.  I always refocus between filter changes as the colour correction on my old Vixen 114 ED refractor is not brilliant, so I guess this was the cause, particularly on the blue channel.  This made it difficult to stack the images for colour composition.  I did my best to manually rotate and resize in PaintShop, but the stars still show some odd haloes where the channels didn't line up.

I made two colour images, one created by the addition of green and blue channels to the H-alpha image above, which was used as the red channel for an RGB composite. This was a rather violent red, as anticipated, so I blended it with an HaRGB stack, which was the usual washed-out pink.  The blend gave a nice colour balance. The blue brilliance of the brighter stars in the cluster has led to some flaring around them.  I find the effect quite pleasing, however.

Clicking on either image pulls up the image icons, which can each be clicked on to "blink" each image. 

The Christmas Tree Cluster is a relatively young open cluster, formed between 3 and 30 million years ago. It is part of the NGC 2264 region, along with the Cone Nebula and the Fox Fur Nebula (Sharpless 273), and belongs to the Monoceros OB1 association, a loose association of very young stars located in the Orion Arm of the Milky Way.

The Christmas Tree Cluster (discovered by William Herschel in 1784) was given its nickname by astronomer Maurice Leyland for its triangular shape, like that of a Christmas tree, as seen through binoculars or a small telescope.  In the image above, the tip of the inverted “tree” is marked by the seventh magnitude star HD 47887 (just above the Cone Nebula as seen at the bottom of the image) with the bright variable star S Monocerotis (15 Monocerotis) to the north forming its “trunk”.

S Monocerotis is a bright irregular eruptive variable.  It is a multiple star system whose primary component is a hot, massive O-type star 10 times the size of the Sun and 30 times as massive.

The “Fox Fur Nebula” (Sharpless 273) can be seen below S Monocerotis in the above image.  Its resemblance to road-kill is quite remarkable, even in these modest images.  The bluish area arises from the reflection of starlight from dust in the region.  Some images show this reflection nebulosity to be much more extensive than seen here, probably because I did not compensate for the poorer blue sensitivity of the CCD with longer blue subs.

The Christmas Tree Cluster is visible to the naked eye in good conditions and appears quite striking in binoculars. The stars forming the Christmas tree shape, along with dozens of other tiny bright stars within the cluster, are a magical sight as seen in my VC200L with a 25mm eyepiece.  None of the associated nebulosity is visible however, at least, not to me.

NGC 2264 is listed as “Hidden Treasure 38” in Stephen O’Meara’s excellent book "Hidden Treasures" in the Cambridge University Press “Deep Sky Companion” series, the relevant excerpt from which can be found here.

M42 - The Great Orion Nebula...

Object: Messier 42 (NGC 1976)
Type: Emission Nebula
Constellation: Orion
Distance: 1340 light years

Date: 01 January 2018
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD

Subframes: 30 x 300s, 100s & 20s H-alpha, 20 x 20s & 100s RGB 2x2 binned, 20 flats for each channel, no darks (hot pixel removal in Astroart instead).

Images were acquired and pre-processed (aligned, stacked, denoised) in AstroArt, then composited in Paint Shop Pro.

The Orion Nebula presents quite a challenge to depict because of the wide brightness range of its key features. Many early CCD images of this object as shown on the web "burn out" the "trapezium" region of the four central stars in attempting to show the outlying nebulosity.

I use the "layers" function in PaintShop Pro, stacking the longest exposures on top of shorter ones, and then carefully use the "eraser" tool to remove overexposed areas, leaving the underlying correctly exposed regions to show through.  This has to be done with care to avoid introducing obvious processing artefacts.

The luminance (H-alpha) channel, processed as described above, is shown below:

Whilst the latest image processing programs such as Pixinsight have "dynamic range adjustment" features that can automatically produce an even distribution of brightness, some of the resultant images can seem rather strange to my eyes.  Programmes like that are way beyond both my budget and my understanding!

LRGB combination (using the H-alpha stack as the luminance channel) went well in both Astroart and PaintShop Pro. The PSP version was a lot greener than the Astroart one (which automatically weights colours given that most CCDs are more sensitive to green light than red or blue, I guess), but I preferred the PSP output as it hinted at the greenish hue of the nebula that is so clearly discernible though the eyepiece.

All of the brighter features seen in the above image show clearly through my VC200L and a 25mm eyepiece. The central trapezium of the four stars brilliantly shine against a bright silvery background, which fades into the convoluted greenish wings of the surrounding nebula.  The dark channel between the main portion of the nebula and the upper candle-flame is clearly seen.

I strove to retain all of these key features in the image above, as well as highlight the extended nebulosity that the eye cannot see.

More information about this object can be found here.

Comet C/2016 R2 (PanSTARRS)...

Click on image to enlarge

Object: Comet C/2016 R2 (PanSTARRS)
Constellation: Taurus
Distance: 2.1796 AU / 326 million km (at time of image)

Date: 19 January 2018
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD

Subframes: 30 x 120s luminance, 20 flats, no darks (hot pixel removal in Astroart instead).

Guiding and stacking using the comet as the reference point has produced trailing stars due to the orbital motion of the comet against the sky background.

Longer exposures through larger apertures (and by far more skilled imagers than I!) evidence much more tail structure than is apparent here.

I could not convince myself that I could actually see the comet through the eyepiece of the ED114, let alone detect the CO-induced blue colouration so evident on long exposure colour images.  

"Supermoon"...

Object: Moon
Distance: 356600 km
Constellation: Gemini
Date: 01 January 2018

Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor,

Subframes: 300 x 0.004s H-alpha, no flats, no darks

Images were obtained via Astroart and then stacked and processed in Registax.

A "supermoon" is defined as a new or full moon which occurs when it is at (or within 90% of) its closest approach to Earth in a given orbit. Supermoons are not uncommon - there are usually between four and six a year on average.

This one is unusual, however, in that it came only 4.5 hours after the moon reached lunar perigee – the moon’s closest point to Earth in its monthly orbit. 

Of the 13 full moons and 14 lunar perigees occurring in 2018, this is the closest alignment of full moon and lunar perigee for the year.  This full moon therefore represents the largest and brightest supermoon of 2018.

M1 - The Crab Nebula...

Click on image to enlarge

Object: Messier 1 (NGC 1952)
Type: Supernova remnant
Constellation: Taurus
Distance: 6500 light years

Date: 27&28 December 2017
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD

Subframes: 30 x 300s H-alpha, 20 x 300s OIII, 20 flats for each channel, no darks

This object is clearly visible in my (200mm aperture) VC200L.  With averted vision some structure can be seen, even from my light-polluted sky. Visually, a dark notch on the eastern side of the nebula does give the object a passing resemblance to a crab's claw, although this is much less apparent on filtered CCD exposures than it is at the eyepiece.  I previously imaged this object in "white light" and the feature shows up quite well.

Subframes for this effort were acquired and preprocessed in Astroart.  I have started to use the hot pixel removal function rather than muck about with dark frames.  My ancient SXV-H9 is not actively cooled so the camera temperature (and hence dark noise) probably varies during an imaging session.  This seems to lead to odd artifacts over long sequences of exposures when using conventional dark frames.  Just hitting any hot pixels with the filter as part of preprocessing seems to a better job and is a lot less effort than making master darks.

For imaging M1, I decided to try colour imaging just based on H-alpha (as red channel) and OIII (as blue channel) data.  The first hurdle came when I looked at my OIII images.  I had not used this filter for CCD imaging before, and the images showed what seemed to be horrendous reflection rings around the stars (section enlarged below).

I contacted Astronomix, the filter manufacturer. They replied that the filter I had was for visual use only, and that the rings were due to it not being IR/UV blocked.  I am not so sure, but will try again sometime with a blocking filter in place.  For the purposes of this image however, I found that the situation was not irretrievable.

When I layered the bloated OIII image stack over the much sharper Ha data and blended in "darken" mode in PSP, this effectively subtracted out the halation, as below, giving a "clean" OIII channel.

To try and avoid the odd pink and blue stars that two colour-only channels seem to give in some instances, I decided to make an additional artificial green channel by layering the above image over the Ha stack and selecting the "multiply" option in PSP.  This allowed me to generate an RGB colour image, using the fake green channel, plus the above OIII image as blue and the Ha stack as red.  I then added the Ha stack back in as the luminance channel to give the final LRGB image.  A bit of tweaking in PSP (curves, cropping) gave the final image as shown at the top.

Quite how "valid" any of this is in terms of true colour is questionable of course, but I think it looks OK and not too unrealistic compared to what else is out there on the web.

The Crab Nebula is perhaps the most intriguing object in the deep sky realm.  Information about it can be found here.

3200 Pheathon

Click on image to enlarge

Object: 3200 Pheathon

Type: Asteroid 

Distance: 0.0797 AU (11.9 million km) 

Constellation: Perseus/Andromeda

Date: 14 December 2017
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 322 x 3s, 17s between frames

The above image shows the track of NEO (Near Earth Object) 3200 Pheathon (pronounced Fay-Ath-On - I think!) as it crossed the Perseus/Andromeda border during the early evening of 14th. December. The field is about a degree wide (52' to be precise).

Images were acquired in Astroart, with selected frames stacked and time-annotated in PaintShopPro. Magnitude of the asteriod appeared to be around 10.7 when compared with similarly bright stars in the image.

The three brightest stars in the image have been labelled by way of positional reference.

Above is a GIF animation using all 322 frames, showing the progression of the asteroid.  A stray meteor crosses the field about a second into the video. I don't think it's a satellite (couldn't find evidence of one in the region at the time from various web searches) or a Geminid (wrong radiant).

3200 Phaethon (1983 TB) was discovered on Oct. 11 1983 by NASA's Infrared Astronomical Satellite (IRAS). Phaethon is the third largest near-Earth asteroid classified as "Potentially Hazardous" after 53319 1999 JM8 (~7 km) and 4183 Cuno (~5.6 km). At over 3 miles wide and moving at 20 km/s, one can only imagine the devastation that this potential "dinosaur killer" might cause were it to strike the UK.

Probably not as much as Brexit of course, although unlike Brexit, there is no risk of such an impact coming to pass in the foreseeable future.

Phaethon is categorized as an Apollo asteroid, as its orbital semi-major axis is greater than that of the Earth's at 1.27 AU (190 million km). It is also suspected to be a member of the Pallas family of asteroids.

Phaethon has an unusually high eccentricity of 0.890 and a perihelion (closest approach to the Sun) of 0.140 AU, the smallest known in the near-earth asteroid population. Its surface temperature at perihelion reaches around 750 C.

Due to the close perihelion, Phaethon is named for the Greek mythological son of Helios (the Sun god). In Greek mythology, Phaethon drove his father's chariot for one day, lost control of its horses, and nearly set the Earth on fire.

On December 16, at its closest approach, the asteroid was only 6.4 million miles (10.3 million kilometers) away, the nearest it will be until 2093. The radar images below were taken by the Arecibo Observatory Planetary Radar during its close fly-by, and have allowed astronomers to distinguish details of its surface.

These images, captured at a resolution of 250 feet (75 meters) per pixel, show the asteroid to be spheroidal in shape, with a diameter of roughly 3.6 miles (6 kilometers). The researchers also used Arecibo’s radar to spot a depression near 3200 Phaethon’s equator that stretches a few hundred meters at minimum, as well as a dark, spherical spot close to one of the asteroid’s poles.

Phaethon’s highly eccentric orbit more closely resembles that of a comet than an asteroid; it has been referred to as a "rock comet".

Phaethon is widely thought to be the parent body for the Geminid meteor stream due to similarities between its orbit and that of the meteors. Most meteor streams are associated with comets, suggesting that Phaethon may be an inactive comet nucleus, although in recent studies performed by NASA's STEREO spacecraft, dust tails have been observed and in 2010, Phaethon was detected ejecting dust.

M33 - The Triangulum Galaxy

Click on image to enlarge

Object: Messier 33 (NGC 598/604)

Type: Spiral galaxy 

Distance: 3,000,000 light years 

Constellation: Triangulum

Date: 25 November & 07 December 2017
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD

Subframes: 50 x 300s luminance (via an Astronomix CLS filter), 20 x 80s 2x2 binned each for Ha, RGB

Images acquired, pre-processed and stacked in Astroart.  Digital development and high/low pass filters applied, colour composited all in Astroart.  Final cosmetic processing (cropping, mild edge preserving smooth for noise) in PaintShop Pro.

The bright red patch at upper right centre is NGC 604, the brightest of the numerous H-alpha emission regions in this galaxy.  This image could have probably done with longer luminance subs as the outer arms are not as well defined as I would have liked.  I had previously imaged M33 in "white light" and actually got better luminance data with shorter exposures, suggesting that the CLS filter wasn't actually helping

More information about this object can be found here.

A 40mm eyepiece on the ED114 shows M33 up as a definite central glow fading to a less obvious oval, featureless glow about half the size of the full moon. This seems to equate to the brighter inner arms as shown in the image above. Visually, I can't see any hint of spiral structure.

The Bubble Nebula NGC 7635

Object: NGC 7635 (Caldwell 11)

Type: Emission Nebula

Distance: 7100 light years 

Constellation: Cassiopeia

Date: 5&6 November 2017
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor, guiding with Lodestar X2/PHD

Subframes: 42 x 300s H-alpha as luminance, 12 x 75s 2x2 binned each for RGB

Images acquired, pre-processed and stacked in Astroart.  Digital development and high/low pass filters applied, colour composited all in Astroart.  Final cosmetic processing (cropping, mild edge preserving smooth for noise) in PaintShop Pro.

More information about this object can be found here...

A faint trace of nebulosity around the bright star inside the Bubble can just be seen with the ED114 and a 25mm eyepiece. Larger aperture scopes don't really reveal any more details, at least not to me.

Open Cluster M52...

Open Cluster in Cassiopeia: Messier 52

Object: Messier 52 (NGC 7654)

Type: Open Cluster 

Distance: 5100 light years 

Constellation: Cassiopeia

Date: 27 October 2017
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 12 x 150 second luminance, 6 x 40 second 2x2 binned each for RGB

Images were acquired, stacked and colour-composited in AstroArt.  Final cosmetic processing was in PaintShop Pro.

This was really just a test of PHD guiding, which I had never used before and which worked just fine, first time.

Visually, this cluster is a real treat through the ED114 and a 15mm eyepiece, looking pretty much as it does in the image given a dark sky.

Jupiter and Io...

This image represented "first light" from my observatory...

Date: 19 May 2017 @ 21.00hrs BST

Equipment: Phillips TouCam Pro II, Celestron C9.25, Vixen x2 Barlow
Subframes: 1 minute @ 20fps, AVI output stacked and sharpened in Registax 2.1.14.

This was really just a test to make sure that the observatory electrics were working and all of the software and hardware were talking to each other.  As it worked out, EQASCOM and SkyMap Pro 9 worked well enough to get Jupiter showing in the finder scope first time, with but a few small tweaks to get the image onto the tiny web cam chip.

Jupiter was only 34 degrees above the southern horizon at the time, and the seeing was pretty unsteady.
Nevertheless, the magic of the Registax processing software recognised enough decent subframes and put them together to give a reasonably decent view.  There are much more recent versions of this magical bit of freeware available, but I like the simplicity of the 15 year old version I have, and for the little bit of planetary imaging I do, it works just fine.

Jupiter's closest moon, Io, was hardly visible on the original image so I took it back into PaintShop Pro to stretch and sharpen it up to make it match the view through the eyepiece.