M67 – An Old Open Cluster

Field Centred at (plate solve from nova.astrometry.net):
RA: 08h 51m 29s
Dec: +11° 49′ 26″
Up is 90.7 degrees E of N

M67 - Open Cluster in CancerM67 is an open cluster located in Cancer – it is much smaller than it’s larger neighbour M44 (The Beehive Cluster/Praesepe), and while not the oldest open cluster (with an age estimated to be 4 billion years), it is close at about 800-900ly distance.

None of the stars are bluer than F spectral class (with the exception of the 30 or so blue stragglers found in the cluster), and there is limited extinction from dust/soot, which makes it an excellent target for study, along with a similarly useful target in NGC188. 

The set of images taken here was also a first test for a new setup in being able to guide using a newly acquired TS OAG9 – this is a very low profile off axis guider and allows me to guide in front of the filters – while this isn’t always required, it makes holding a guide star much easier, especially for narrowband work where guiding with the guide chip in the camera can be nigh-on impossible! This setup allows me to guide using PHD2 and image using APT (with the advantage of having it’s own focus control and platesolving capabilities, as well as Astrotortilla being able to take images to make platesolving/mount alignment much easier). 

Images were taken on 15th and 20th March 2017 from West Oxfordshire, using the SBIG ST2000XM on a William Optics FLT110 working at |f5.7 with the FLAT4 reducer. Guiding was performed off-axis by my ASI120MM, controlled by PHD2. 

Exposures were:
R:G:B = 90:75:65 (all in 300sec subs). 

Reduction/Processing in Pixinsight and Photoshop CS4.

M31, NGC206 and the Bologna Catalogue

NGC206 Region in M31 - Lum ChannelPresented here is a bit of a “nonsense image” of the Andromeda Galaxy, M31, that I grabbed early in the evening of the 22nd Jan 2017. This was a quick run, mainly while I was waiting for another target to clear the tree near my observatory…!

However, even in an image like this, which only consists of 14x5min exposures through a luminance filter, there is lots to be explored – first it gives me a good idea about future plans for a mosaic (though this will have to wait until the autumn now, and may be a major undertaking…). It also gives a good view of NGC 206, which is a bright star cloud in M31, and I plan to image this alone at longer focal lengths later on. Also, it allows me to explore objects in the Bologna Catalogue 1.

NGC206 Region in M31, with Bologna Catalogue Globular Clusters AnnotatedThis catalogue  is not one that comes immediately to mind when talking about deep-sky objects – but it is a very specialised list describing globular clusters (GCs), candidate GCs and previous candidate GCs in M31. The up to date version of the catalogue is freely available on the Bologna Catalogue website and can be downloaded, manipulated and used as a source of information for the Annotate script in Pixinsight. Presented here in negative format is the south west region of M31, with overlaid markers for the confirmed GCs in the Bologna Catalogue v.5 (with associated V magnitudes) in red, as well as a few small PGC galaxies that loiter in the field marked in light blue. There are 181 marked objects alone in this field – most of which have been successfully captured using just a small 4 1/2″ refractor!

Image details:

ST2000XM, William Optics FLT110 + FLAT4 reducer
14x5min, L filter
Reduced and processed in Pixinsight

References

1. Galleti S., Federici L., Bellazzini M., Fusi Pecci F., Macrina S.: “2MASS NIR photometry for 693 candidate globular clusters in M31 and the Revised Bologna Catalogue (V.1.0)”, Astron.&Astrophys., 2004, 416, 917 (G04)

M36, Carbon Star OW Aur & Holoea

Field Centred at: 
RA: 05h 36m 25s
Dec: +34° 07′ 24″
Up is -89.8 degrees E of N
(Plate solve by nova.astrometry.net)

M36 in AurigaM36 is one of the three bright open clusters in Auriga. It was catalogued by Charles Messier on the night of 2nd Sept 1764, though it had been previously discovered at least 110 years prior to this by Italian astronomer Giovanni Batista Hodierna. Despite being one of the fainter open clusters in Messier’s catalogue (though M38, also in Auriga is the fainter of the three), it is visible with the naked eye from a dark site.

There are about 60 stars in the cluster itself at a distance of about 4100 light years. It is very similar in extent to the Pleiades, and if it was at the same distance, it would likely appear just as bright!

In this image to the lower left (south west – north is to the right here) there is the deep red variable star OW Aur. This is another carbon star, similar to V358 Aur as imaged near to M37

Holoea - YSO in M36
Holoea – YSO in M36

Also of note in the object, though only just visible at this scale (shown at 200% scale on left) is an enigmatic object with the name “Holoea” – this is an object that has a tail like structure with high velocity outflows, and is likely to be a young stellar object. Details on the discovery and analysis of this object can be found at 1996A&A…305..936M (Magnier, E. A.; Waters, L. B. F. M.; Kuan, Y.-J.; Chu, Y.-H.; Taylor, A. R.; Matthews, H. E.; Martin, E. L.)

The data presented here was taken on the evening of 30th Nov 2016 as an opportune target while waiting for another object to be in a favourable position. As such, exposures were fairly short, totalling 45:40:40 R:G:B (all unbinned, 5min sub exposures). Reduction/processing was performed in Pixinsight with final tweaks in Photoshop. During processing in PI, I generated a pseudo-Luminance frame from the combined RGB data and then merged this back to form the LRGB image shown. 

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.

M33 – The Triangulum Galaxy

RA: 01h 33m 54.0s
Dec: +30° 40′ 15.8″
Up is -89.8°E of N
(Plate solve by nova.astrometry.net)
M33 - Triangulum GalaxyMessier 33 is a spiral galaxy in the constellation of Triangulum, and is sometimes called the Pinwheel  Galaxy, a name it shares with M101, It is the third largest member of the Local Group of galaxies with a diameter of about 60,000 light years; the two larger members being our Milky Way and the Andromeda Galaxy (M31). There is suggestion that M33 and Andromeda have experienced an encounter at some point in the past (and will do again in the future!).

M33 is one of the most distant objects visible to the naked eye, but it is a relatively diffuse galaxy, and so it’s visibility with the naked eye and through binoculars is strongly affected by light pollution and sky transparency – in this respect, M31 is far more visible to the naked eye. 

There are lots of H-II star forming regions within M33 that are visible as pinkish areas of hydrogen emission in the spiral arms. The largest of these is NGC604 which was catalogued independently of the galaxy core by William Herschel. This area is probably very similar to the Orion Nebula in many ways, and can be found to the north-east (upper-right) of the core of the galaxy (north is to the right in the images).

The images were all taken across several nights in November 2016 (7th, 28th, 29th) from West Oxfordshire with an SBIG ST-2000XM though a William Optics FLT110, all mounted on the Losmandy Titan. Exposures were as follows:

L:R:G:B
310 (31x10m) : 95 : 90 : 80 (RGB in 5m subs, 2×2 binned)
All exposures taken at -20°C.

Reduction and processing performed in Pixinsight and Photoshop. The processing of this object proved tricky. The galaxy largely fills the field and leaves relatively little background to work with in running DBE processes. This left several colour casts and gradients that I needed to manually remove within Photoshop – not an easy task…  

M33 HDR EnhancedAlso included here is a luminance only channel using the L channel data, that has been processed using HDR Multiscale Transform, Local Histogram Equalization and TGV Denoise to reveal to a greater extent the structure of the galaxy – in many ways this might be regarded as “over-processed”, but an interesting take on the galaxy nevertheless. 

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