Tag Archives: FLT110

astroimaging, astronomy, open clusters

M37 & Carbon Star V358 Aur

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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. 

astroimaging, astronomy, equipment, nebulae, open clusters

Bubble Nebula + M52; Equipment Updates

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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)

astroimaging, astronomy, eclipses, lunar, published work

Total Lunar Eclipse – Sept 28th 2015

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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)!

[Show thumbnails]

astroimaging, astronomy, published work, solar

Transit of Mercury, 9th May 2016

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On 9th May 2016, Mercury transited the sun as viewed from Earth for the first time since November 2006. The transit was well timed for observation from The UK and Europe, starting at 11:12UT and ending at 18:42UTSolar Imaging Setup. I attempted to view and to photograph the transit using both my WO FLT110 with a Herschel Wedge from Lacerta, as well as visual work through the Takahashi FC60.

To image the eclipse, I used a combination of the WO FLT110 working at native f7 using the Herschel Wedge, with ND3.0, IR/UV blocking and Wratten #57 filters. Situated behind this combination was the ASI120MM camera – the plan being to take video captures of the event, processing into images later with Auostakkert/Registax.

However, British weather being itself, I only had a very short window of clear sky at the beginning of the transit during which I could grab one decent shot showing Mercury (bottom left), AR12542 (top) and AR12543 (lower), and with AR12544 developing at the top left. This image made it onto the Meridian (West) news at 6pm that evening, and is on Simon Parkin’s Mercury Transit blog post as well.

Transit of Mercury, 2016-05-09 1250 UT

After this 10 minute spell of clear(ish) sky, I had very little opportunity to see the transit again – there was a short period here and there where I was able to visually observe Mercury and the sunspots on the disc, but by 3pm I was completely clouded out, with rain following later in the evening….

Clouded out for the Transit of Mercury...

astroimaging, astronomy, nebulae

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

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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