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. 

M37 & Carbon Star V358 Aur

RA: 05h 52m 16.8s
Dec: +32° 32′ 07.6″
Up is -179 degrees E of N
(Plate-solve by nova.astrometry.net)

I took a short set of subs late at the end of an imaging run on the Bubble Nebula, concentrating on the open cluster M37 in Auriga. 

As it was so late, images were restricted to RGB 35:35:35 (all 7x5min subs) unbinned at 1×1, though I find I get better star colours with RGB only processing. They were processed in Pixinsight as the first RGB image I’d put through it – while there was a bit of getting used to the order of the processes required and the methods of colour balancing and combining, I think I managed to get the result somewhere near to what I was after, while also preserving star colour in what is quite a rich open cluster. 

M37 in AurigaTo the bottom (centre-left) of the frame, there is a particularly red star which is the irregular variable star V358 Aur (Magnitude V 12.2, R 11.4). This is a carbon star (ie class C), which are cool (often giant) stars with dominant absorption lines from C2 molecules (the Swan bands), as well as absorption features from other larger carbon compounds. These compounds give the outer atmosphere of the stars a “sooty” makeup and a striking red colour. 

All subs taken on 6th Nov 2016 from 01:45UT. 

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)

Total Lunar Eclipse – Sept 28th 2015

A way overdue gallery post, as I have finally managed to sort and post my images of the September 2015 Total Lunar Eclipse. The weather was excellent in Oxfordshire for this event which started at 01:11UT and finished at 06:22UT.

This eclipse occurred with the moon close to perigee, and appeared very dark to the naked eye. Our daughter (aged 5) even got up in the middle of the night to have a look through Daddy’s telescope at the moon and did this amazing drawing the next morning all by herself!

Abi's Amazing Lunar Eclipse Drawing

My image around maximum eclipse was used on the Oxford Mail website as the header image for the article on the event. The gallery below is a selection of images from all the ones I took – these were all taken using a Nikon D70s through a William Optics 110FLT. Exposures range from fractions of seconds for the partial phases, right up to 10 seconds for the images at maximum, which shows the range of brightness across the whole eclipse. My imaging finished at about 6am when the moon was occulted by the garden fence so I didn’t quite get the last stages of the eclipse (though I got an hour or so back in bed before work)!

Lunar Imaging Gallery – 16th May 2016

Some further lunar work – as before I worked using the ASI120MM in combination with a 2x Barlow lens and the 742nm near-IR filter through the 350mm Newtonian.

A productive evening, with six images of good quality in what was at times fairly good seeing – I would like to try running at a slightly higher scale (by using a different Barlow). i do have a 4x Imagemate, but I’m not sure the quality or the resultant focal length would work quite as well.

As it turned out, this was an evening where I bagged a few of the double ringed (concentric) craters on the moon, as well as some interesting Rille features and domes.

Images are as follows:

Clavius with Longomontanus, Scheiner and Blancanus – a good amount of detail in this image and I’m especially pleased with the detail within Rutherfurd (on the southern edge of Clavius). Street M is visible with a small concentric craterlet within.

Longomontanus and Clavius, 2016-05-16

Moretus, with some very good detail coming out of the wall and surrounds. The lunar south pole region (with Newton tucked just behind the hills) is to the bottom of the image.

Moretus, 2016-05-16

Copernicus – a classic lunar crater, and one where I’ve got a much better result than I’ve previously acheived. I particularly like the collapsed edge visible to the south – perhaps a little more scale might just let me sharpen up the detail within the crater a little… Also visible are the Hortensius domes (to the left in the image) lying just to the north of the crater of the same name – lunar domes are shield volcanoes which often have a small craterlet at the peak.

Copernicus, 2016-05-16

 

Rimae Hippalus and surrounds. So much going on in this region – bullialdus by itself is a nice looking crater, and nearby the complex rille structures of Rimae Hippalus cut across Hippalus and the surrounding regions, leading up to Agatharchides. The lunar dome Kies Pi is easily visible and concentric crater Marth in Palus Epidemarium is also present in the bottom right of the image.

Rimae Hippalus and Surrounds, 2016-05-17

Another busy nearby field, showing Pitatus, concentric craters Hesiodus A and Marth. Lots of rilles also visible, including Rimae Hippalus, Rimae Ramsden, Rima Hesiodus, rilles in Pitatus, and Rima Campanus cutting between Campanus and Mercator. Kies Pi is again obvious.

Mare Nubium and Palus Epidemiarus, 2016-05-16

A view north of Bullialdus including the interesting “rippled” texture between Darney and Euclides.

Bullialdus and Mare Nubium, 2016-05-16

The last two make a rather nice mosaic, though this was a quick job and I haven’t tried too hard to eliminate the edge of field noise, or the slight mismatch between levels.

Bullialdus Region - Mosaic

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