Category Archives: nebulae

M78 – Reflection, Dust and Star Birth in Orion

Field Centred at (plate-solve by nova.astrometry.net):
RA: 05h 46m 40.4s
Dec: +00° 12′ 10.2″
North is up

M78 in Orion in LRGBOrion is a rich area for deep-sky objects, and it’s somewhat of a shame that M78 is so often overlooked, with the Orion Nebula, Horsehead and Flame taking centre stage.

There are three main areas of reflection nebulosity present here, the larger, bluer of which (M78 itself) is illuminated by the stars HD 38563A/38563B and appears split in two by an obscuring dark dust lane. The area of nebulosity to the west (right) of M78 itself is catalogued as NGC 2064 and NGC 2067, though, the actual catalogue designations become hard to follow as the whole region shows nebulosity that merges into one combined region…

The smaller area of nebulosity to the north (NGC 2071) is illuminated by HD 290861 and is encompassed by further blue reflection nebula. It is also surrounded by the continuation of the sinuous dust lane.

Herbig Haro 22, 24 & McNeil's Nebula
Herbig Haro 22, 24 & McNeil’s Nebula

The dust in this image hides a lot of hidden activity – some of which is revealed in the image and is highlighted in the crop (displayed at 200%) – this shows Herbig-Haro 22 and 24 along with McNeil’s Nebula (top-centre). Within these regions, newly born stars start to illuminate gas around their birthplace, while jets of material from these stars collide with surrounding gas and dust.

T Tauri type stars are also found in these dusty regions. These are stars that do not have a core hot enough to trigger hydrogen fusion (but may burn lithium), and are not yet in hydrostatic equilibrium, whereby gravitational forces are balanced by outward pressure due to heat from within the star. Heat is produced by gravitational contraction during this intermediate phase between a true protostar and a main sequence star. It does offer a look back in time to a phase our own sun would have passed through before the formation of the solar system  from the solar nebula.

Bernes 100
Bernes 100

Finally, to the top (north) of the image, we start to see a large area of HII emission that merges into Barnard’s Loop. Within this, there is an interesting bright nebula near HD 290857 with only one reference that I’ve been able to find through Simbad. The reference comes from a 1977 paper, “A catalogue of bright nebulosities in opaque dust clouds” (Bernes C., 1977A&AS…29…65B), and as such the nebula gets the classification Be 100 (listed as [B77] 100 in Simbad). The nebula (shown) forms part of the much larger L1630 molecular cloud.

Image was taken using William Optics FLT110 with FLAT4 reducer; SBIG ST2000XM; Losmandy Titan with Gemini 2. 

L: 6h45m (21x15m + 9x10m)
R: 3h (18x10m, 2×2 bin)
G: 2h30m (15x10m, 2×2 bin)
B: 2h20m (14x10m, 2×2 bin)

Reduction and processing in Pixinsight and Photoshop CS4. 

Images acquired Nov/Dec 2016 from Oxfordshire, UK.

Bubble Nebula + M52; Equipment Updates

The past few months have seen some changes to my equipment – unfortunately the biggest (or most expensive) change was due to my original Gemini 1 controller dying. The mount is back in action after I upgraded to a Gemini 2 from Losmandy via an existing owner trade-in. Good news is that the mount appears to be working well, though still needs PEC sorting and full building of pointing models.

I’ve also got a 0.8x reducer/flattener for the William Optics FLT110 (this is the latest model of the William Optics FLAT4 reducer), allowing me a larger field of view on the SBIG ST2000X, a flatter, faster field, and also the ability to mount a recently acquired, astro-modded Canon 350d on there as well – I look forward to trying to image the Pleiades and the Orion Nebula using a sensitive, wide field arrangement this winter… I also have started to use Pixinsight for processing images; while it’s been a learning curve for me, I feel I’m starting to get somewhere in using it, and think it could be a very powerful tool.

Bubble Nebula (NGC7635) & M52I have managed to put the new kit to use already: after tuning the spacing for the CCD camera, I managed to take a lot of sub-frames of the Bubble Nebula (NGC 7635) and M52. The image shown is in H-Alpha (using the Astrodon 5nm filter) and consists of 7hrs total in 20min subframes (at -20C). 

The Bubble itself is a large  (~7 light year) void formed by the action of the fierce stellar wind from a hot, highly luminous Wolf-Rayet star. This star also causes excitation of the surrounding nebula, giving us the H-Alpha light we image here. M52 is the open cluster to the bottom right, with Czernik 43 the slightly looser open cluster to the right of the image. The nebulosity to the bottom left is part of the larger region SH2-158, and the smaller areas of nebulosity to the top centre-left of the frame is the not often referenced planetary nebula KjPn8 (though this is quite faint here and needs a bit more magnification, and a lot more data to pull out well!)

Field is centred at: 
RA: 23h 22m 29.0s
Dec: +61° 19′ 07.7″
Up is 0.71 degrees E of N
(plate-solve from nova.astrometry.net)

M42, The Orion Nebula in H-Alpha (work in progress)

RA (centre): 05h 35m 10.9s
Dec (centre): -05° 28′ 54.4″
(Results from nova.astrometry.net)

On February 10th, I managed to get some first data on a project in imaging the Orion Nebula with the FLT110/ST2000-XM combo. I had a fair bit of equipment issues here before starting – I have changed scope and was trying a newer PC. I had issues in getting the computer to connect to the ASCOM focuser and so resorted to an old laptop, thus wasting time.

I also had some guiding issues with PEC on – I think this is related to balance (the mount should have been more weighted towards the east) – and not to mention the object skirting the trees resulting in some spurious guiding results and the loss of 6 frames…

Finally (!), it became apparent when doing the flats that there was frosting on the chip – I’m not sure if this was the case before (though it doesn’t show), but this did mean I needed to run the flats at 2C, rather than -20C like the lights.

Even so, results are encouraging – this is the result of 27 x 3min with an Astrodon 6nm filter – this is one of the older narrowband range filters – running at -20C at f7. This needs much more data, as well as luminosity and colour channels to allow me to merge it into an L/Ha-Ha/R,G,B image  – the fainter regions are fairly noisy, which is not helped by short exposure, and the introduction of noise from the warmer flats, and dark frames for the flats.

Processing objects like the Orion nebula is always a little tricky, and I’ve tried to tame the vast dynamic range here by using luminosity masks in Photoshop (with four differently processed versions of the same image) to preserve the detail within the Trapezium, while also allowing me to bring out outer detail. If I can get a good enough night to get more data, I should be able to further blend in more data for the outside regions (possibly by using longer subs). The RGB combine should be interesting, and might need a bit of pushing of the H-Alpha data as it does get a bit diluted in the process.

M4, The Orion Nebula in H-Alpha - work in progress

M42, M43, NGC 1977 – The Orion Nebula and Running Man

RA: 05h 35m 17s, Dec: -5°23’28” m42-200702061024.jpg
The Orion Nebula (M42 (NGC 1976) & M43) is located in the “sword” of Orion and is a large emission nebula that is easily visible to the naked eye. It is an area of star formation – the closest such to Earth at a distance of 1500 light years. The nebula is an estimated 30 light years across, and contains a young star cluster (the Trapezium) in the bright core of the nebula. The reflection nebula at the top of the image is the “Running Man” nebula (NGC 1973, 1975 and 1977) – so named due to the resemblance of the silhouetted dust lanes.

I had lots of trouble with this image (taken on 6th Feb, 2007) – the flats I took didn’t work out (there’s the odd artifact here and there!), and I’m not quite happy with the colour balance – have another go at this later I think…

NGC2264 – The Cone Nebula and Christmas Tree Cluster

RA: 06h 41m, Dec: +9°53′ ngc2264_20061221.jpg
The Cone Nebula and Christmas Tree Cluster are part of a larger star forming complex within the constellation of Monoceros. A 2.5 hour exposure in H-Alpha light taken 22nd December 2006 using an Astrodon filter shows only glowing hydrogen gas and stars – the blue reflection nebula near to the “Fox Fur” nebula (below the bright variable star S Monocerotis) often seen in photos of this region is largely invisible as most light is of the wrong wavelength and is rejected by the filter.