alan4908

22 hours ago, maw lod qan said:

Excellent, and like always thanks for the information you give with the image!

It always amazes me at the number of galaxies you see off in the distance of these images.

Cant help but remember Star Wars.

"In a galaxy, far, far away!"

Thanks - yes, the galaxies, particularly the (annotated) background ones seem to be be particularly distant (c700m light years). 

If you look closely at the image, you can also see that Pixinsight did not pick up all these in the annotated image, maybe these are even further away 

Alan

16 hours ago, michael.h.f.wilkinson said:

Lovely image. Wonderful colour and detail

Thanks for the comment Michael. 

Alan

M108 is a spiral galaxy 46 million light years distant in Ursa Major. It is inclined at 75 degrees from the viewers perspective, so the spiral structure is hidden from view.  Visually it appears as a relatively small object (11.1’ x 4.6’) with an apparent magnitude of 10.7. Its core is estimated to contain a supermassive black hole with an estimated mass of 24 million solar masses.

 I was pleased to capture quite a bit of detail on the galaxy including the Ha emission areas. The background also contains many small, more distant, galaxies.

The LRGB image below was taken with my Esprit 150 and represents 14.5 hours integration time.

Alan

M108

M108 (annotated)

LIGHTS: L:34, R:20, G:15, B:18 x 600s; DARKS:30; FLATS:40;BIAS:100 all at -20C.

17 hours ago, MartinB said:

Oooh! This is a new one on me.  Nice to have a new target to think about!  This is a very well executed image, nice star colour and a great job integrating the Ha with the RGB.

Thanks Martin. Yes, this is not often imaged, probably because of its small apparent size - I was at 0.7 arc seconds/pixel but still cropped the image in order for the detail to stand out a little more. On the Ha blend with the RGB I'm now use Adam Block's technique, which I find more effect than my previous method.  Basically, you create a starless Ha and blend only the brightest parts via a Screen script into the Red channel. A video tutorial  on this can be found at   https://www.adamblockstudios.com/ - I would definitely  recommend the videos. 

16 hours ago, Allinthehead said:

Very nice Alan, a new one for me too.

Thanks for the comment ! 

Alan

16 hours ago, simmo39 said:

Nice!

Thanks for the comment ! 

Alan

Discovered by William Herschel in 1790, NGC 1491 is a bright emission nebula in Perseus about 12,000 light years distant and about 21 light years wide. Despite its large size, its distance from Earth means that it appears visually small.

The HII region displays a great deal of structure. The 11^th magnitude white/blue type O5 star BD+50 866, located near to the centre of the image below, illuminates the nearby hydrogen gas with high intensity ultra violet radiation, ionising the gas. Material ejected by the star has also created curtain fold and half bubble effects in the surrounding HII region. The bubble, which is closer to the star, is probably the result of high speed, gas outflows that push nearby gas and dust outward, creating a shock front and forming a layer around the star with variable density. A similar effect also seen in the bubble nebula, NGC 7635.  Further from the star, the ionised ejected gas gradually slows down as it expands into non-ionised hydrogen. The boundary between the ionised non-ionised hydrogen is called an ionisation front which may have created the curtain fold.

I decided to try to extract as much detail as possible by acquiring a significant amount of Ha data which was then blended into the Lum and Red channels. The structure within the brightest regions was better revealed after application of PI’s HDRMT.

The image below represents 21 hours integration time and was taken with my Esprit 150.

Alan

LIGHTS: L:19, R:20;G:20:B:23 x 600s; Ha:21 x 1800s; BIAS:100; DARKS:30; FLATS:40 all at -20C.

14 hours ago, Adam J said:

Great image! 

Thanks for the comment Adam.

Alan

23 hours ago, peter shah said:

star colour is great...nice work

Thanks for the comment Peter. I did spend quite a lot of time on the star field colours, mainly because I acquired quite a few sub frames in non ideal conditions.  However, I agree, I think the end result looks OK - it is amazing what you can do in post processing !

Alan

22 hours ago, ultranova said:

Nice to see this cluster, not that often taken.

nice star colors .

well done 

Paul

Thanks Paul - yes, not often see here - which probably due to its small apparent size.  As I mentioned above, even at 0.7 arc seconds/pixel, I decided to crop the image to create more visual impact.

12 hours ago, michael.h.f.wilkinson said:

Very nice capture. I should try this one with my 6" F/5 Schmidt-Newton 

Thanks Michael  - good luck with your forthcoming capture.

Alan

11 hours ago, glafnazur said:

Superb image, so much detail 👍

Thanks for the comment 

Alan

18 hours ago, orionoffelt said:

Nice capture on a difficult target.

Thanks !

Alan

23 hours ago, Knight of Clear Skies said:

Nice image with the contrasting colours in the cluster, and appreciated the write-up.

Thanks - glad that you liked the end result. 

(I discovered that I had  a red glow around all my stars due to my FWHM of my red channel stars being much larger than the other colour channels. This was due to the fact that I acquired the majority of the subframes in non ideal conditions. However, I corrected for this effect by eroding the red channel through a star halo mask)

Alan

23 hours ago, Graham Darke said:

That is lovely that Alan. This object is on my list to capture.  I've seen it visually a number of times but don't have an image of it yet. 

Thanks for the comment Graham - good luck with your capture. 

Beware that it has a small apparent size,  I was imaging at 0.7 arc seconds/pixel but even at that level I decided to crop the image down to focus the viewers attention on the cluster.

Alan

Discovered in 1788 by William Herschel, NGC 2419 is one of the most massive and brightest globular clusters but appears as a dim 9^th Magnitude object due to its large (275,000 light years) distance from Earth. The bright blue star to the left of NGC 2419 in the image below is HD60771, which is much closer, being only 350 light years distant.

In 1944, the American astronomer named it the “Intergalactic Tramp”, since it was once (erroneously) thought not to be orbit around our galaxy but rather wandering the space between Earth and the even more distant galaxies.

More recent observations have confirmed that although NGC 2419 is very distant, it is still trapped by our galaxy’s gravity well, taking 3 billion years to complete an orbit.  The orbit places it even further away that the Milky Way’s most famous satellite, the Large Magellenic Cloud and even further away that the Small Magellenic Cloud.

The image below was taken with my Esprit 150 and represents 11.3 hours integration time.

Alan

LIGHTS: L:23, R:22, G:10, B:13 x 600s, BIAS:100, DARKS:30, FLATS:40 all at -20C.

On 10/02/2021 at 15:06, Sunshine said:

Fantastic image, such subtle detail visible in NGC4248.

Thanks for the comment 

23 hours ago, tomato said:

Superb result, great framing, colour and detail.👍

Thanks.

23 hours ago, peter shah said:

love it....super colour and detail

Thanks Peter  - I think I prefer the colour in this reprocess of the ED 80 data - this time I used Pixinsight's Photometric Colour Calibration process. 

Alan

Whilst waiting for clear weather, I decided to reuse some data that was previously acquired by my Skywatcher ED80 and my Esprit 150.   I used the Esprit data to get maximum detail on M106 and its companion NGC4248, whilst I reprocessed the ED 80 data such that the resultant background showed very faint objects.

The ED 80 data is LRGB whilst the Esprit data also contains a Ha blend into the red channel. On the processing side, I used RegiStar to align the Esprit 150 and ED 80 images and then used Pixinsight's Gradient Mosaic Merge to create a seamless image. 

Alan

M106

M106 (annotated)

Here's five of my favorites from 2020, all taken with an Esprit 150 and a SX Trius 814.

Alan

NGC3718

NGC4725

NGC6995

Vdb152

M94

On 20/01/2021 at 11:44, Richie092 said:

Well that was definitely worth waiting for!

Thanks  - I don't think I could have done this without an automated set up.

20 hours ago, MartinB said:

Crikey, that is amazing.  I know there are some dark sky areas in your neck of the woods but didn't know they were this good.  Beautifully processed as well.

Thanks Martin ! I'm fortunate to live at a location which (by UK standards) has very good dark skies. I'm also at the top of a hill which helps, although it does get rather windy at times.

My image generating productivity has been significantly decreased by the poor UK weather in recent months. Even with an automated observatory, my image capturing has been moving at a glacial rate. However, here’s the latest image to finally emerge from my set up – NGC 7497 

NGC 7497 is a spiral galaxy in the Pegasus constellation, approximately 60 million light years distant with a disc size of approximately 91000 light years.  The galaxy shows signs of warping indicating past interactions. You can (just) make out some HII regions in the image below that appear to be semi-randomly positioned within the galaxy.

The galaxy is viewed away from the plane of our own galaxy, through a mass of dust and gas known as Integrated Flux Nebula (IFN), which resides in our own galaxy and is approximately 600 light years distant. The stars within our galaxy act together in an integrated fashion to faintly illuminate the gas, hence the name.

In 1985, the astronomers Magnani, Blitz and Munday (MBM), decided to catalogue the various IFNs and the one shown is known as MBM 54.

The image also features many stars and a several background galaxies. Some of the stars are closer to Earth than MBM 54 and appear sharp and distinct (eg the bright blue star at the top, middle) and some are more distant.  The more distant objects will therefore appear fuzzy if they are viewed though dust and nebulosity.

The LRGB image below represents just under 16 hours integration time and was taken with my Esprit 150. 

Alan

LIGHTS: L:37, R:20, G:20, B:18 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.  

A second attempt at the Witch’s Broom Nebula (NGC6960), this time in narrowband. It took me 3.5 months to acquire the data, which was caused by a combination of poor UK weather and the partial obstruction by trees at my location. Anyway, better late than never....

Although imaged in narrowband, I tried to go for realistic looking colours so started with Ha mapped to red and OIII mapped to blue with a synthetic green generated from a Ha/OIII mix.  After a few hue adjustments, I ended up with a colour image which mainly gave blue/reddish stars and nebula. I found that detail could be boosted by creating a super luminance image from the individually stacked narrow band stacks and then deconvolving the result which I then blended into the colour result via Pixinsight’s LRGB process.

The image below was taken with my Esprit 150 and represents 16.5 hours integration time.

LIGHTS: Ha: 15, OIII: 18 x 1800s; DARKS:30, BIAS:100, FLATS:40 all at -20C.

NGC 896 is an emission nebula located in Cassiopeia about 7500 light years away. It is also the brightest part of the Heart Nebula (IC 1805) but has a separate classification, since it was the first part of the nebula to be discovered.  The dominant red colour arises from hydrogen line photon emissions created by intense ultraviolet emissions from nearby stars. It is a star forming region and also home to many dark lanes created by interstellar gas. Some very bright blue stars compete in the nebula illumination, resulting in a blue/red cast in certain parts of the image.

The LRGB image has an Ha blend into both the red and lum channel and was taken with my Esprit 150. It represents 18.5 hours integration time.

Alan

LIGHTS: L:22, R:18, G:11, B:12 x 600s; Ha: 16 x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.

21 hours ago, andrew s said:

I prefer the original colour balance. Nice subject well framed.

Regards Andrew 

Thanks for the comment Andrew. In terms of the colour balance, I was drawn to change this when I checked the histogram levels which shows that the original image is quite unbalanced at the lower levels, however, I also like the "more blue" effect in the original.

I I think the credit for the framing goes to CCDNavigator (where you can preview the image for your given FoV) and ACP, for actually getting the object in the center of the FoV.  As an aside, CCDNavigator was recently made compatible with ACP Expert which enables you select objects to image through a view mouse clicks, which I really like. 

21 hours ago, ultranova said:

A nice close up of that area,

you have certainly done it justice, great colours and processing.

Nicely done

Paul

Thanks Paul ! 

Alan

Hmmm - I decided that the RGB background levels are not optimal on these images and so applied PI Background Neutralization tool to make them a little more balanced. 

Located in the Cygnus constellation about 6000 light years distant, NGC6914 is a blue reflection nebula consisting of VbB131 and VdB132.  

Surrounding NGC6914 are reddish areas of hydrogen emission nebula which provide a dramatic colour contrast to the blue nebulosity.  The contrast is further increased by regions dark nebulosity (LDN 899).

The stars are also a notable feature of the image since embedded within the nebula is the star cluster Cygnus OB2 which consists of about 100 class “O” (yellow)  and 2500 class “B” (blue-white) stars.

The image was taken with my Esprit 150 and represents 16.5 hours integration time. It is an LRGB image with a Ha blend into both the Red and Lum channels.

Alan

LIGHTS: L:21, R:17,G:12, B:16 x 600s; Ha:11 x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.

15 hours ago, Allinthehead said:

That's a beauty Alan👍

Thanks 

14 hours ago, Erling G-P said:

That's a stunning looking image!

Glad you liked it - it is a pity that it doesn't appear a little more often here.

9 hours ago, John Nodding said:

Cracking image! Should be called the My little Pony Nebula. 👀

Noddy

Thanks Noddy - yes, it is quite amazing what the brain sees when you star at nebula's for a while....

LBN 438 is a dusty nebula located in the Lacerta constellation which is also known as the sand worm (from the Dune science fiction series) or the shark nebula.  It doesn’t appear very often on SGL, probably because it is so faint !

It is illuminated by interstellar radiation known as Extended Red Emission (ERE).   ERE is a relatively recent discovery (1975) and is a photo-luminescence process whereby hydrogenated amorphous carbon is illuminated by interstellar photons in the 500 to 1000nm spectral range.  Although the nebula also contains ionized hydrogen, it only emits a relatively weak Ha signal, so I decided to only use broadband filters to acquire the target.  

The LRGB image shown below was captured with my Esprit 150 and represents just over 13 hours integration time.

At the top of nebula is a reddish glow, which I presume is due to ERE.  The nebula is surrounded by very bright blue stars which can detract from the relatively faint nebula, so these have been stretched much less than the rest of the image and then blended back into the main image.  If you look closely at the background you will also be able to see various small background galaxies (eg middle left).

I hope you like it.

Alan

LIGHTS:   L:31, R:17, G:15, B:17 x 600s; DARKS:30; BIAS:100; FLATS:40 all at -20C.