alan4908

Thanks for the comment ! Thanks, yes IC771 does look interesting, I was quite surprised how blue it came out. Thanks Bob - I think the deconvolution on the stacked Lum data helped to bring out the detail. Alan

The galaxy NGC4216 is in the Virgo Cluster about 55 million light years from Earth. It is shown in the center of the LRGB image below with two main companions NGC4206 (top) and NGC4222 (bottom). Also displayed are a few background galaxies. The inclination of NGC4216 is 89 degrees so, it is almost edge on, making the revelation of dust lanes difficult, so I was quite pleased that I managed to capture a few details. I've also inserted an annotated version which shows the location of the background galaxies (if there are any PI experts who know how to stop PI writing different annotation identifiers to the same object please let me know.....). The image represents 12.5 hours integration time and was taken with my Esprit 150. Alan LIGHTS: L:19, R:12, G:14, B:30 x 600s. DARKS:30, BIAS:100, FLATS:40 all at -20C.

Thanks for the comment. Yes, I agree about the tidal tale, I was a little surprised about the length ! Thanks - yes, it took me quite a long time to acquire this, just below 7months..... Thanks - looking at my captured data my imaging started at 13th May and finished 5th December, so quite a long acquisition period which is not helped by the fact that I'm surround by trees which limits my local horizon. Since I have to dodge trees, certain phases of the moon and bad weather, I just let ACP work out when to image it. FYI, at my location gets to about 75 degrees at dark end. Alan

Here's one you don't see often: - Arp297 which consists of four galaxies NGC5752, NGC5753, NGC5754 and NGC5755 all of which are located in Bootes. NGC5754 and NGC5752 are approx 200 million light years distance whilst NGC5753 and NGC5755 are much further away, at approx 450million light years. The more distant galaxies don't appear to be interacting now, although the extended arms of NGC5755 indicate that an interaction may of occurred in the distant past. By contrast, a gravitational interaction of the closer two galaxies has produced an extremely long (275,000 light years) tidal tale which extends from the starburst galaxy NGC5752, which you can just about see this on the image below. NGC5754 appears relatively unaffected by the collision. This LRGB image represents just over 11 hours integration and was taken with my Esprit 150. Alan LIGHTS: L:29, R:12, G:16, B:11 x 600s. DARKS: 30, BIAS:100, FLATS:40 all at -20C.

Thanks. Yes, this one is hiding in plain sight ! Alan

Thanks for the comment ! Alan

SH2-112 is an emission nebula in Cygnus and responds very well to Ha imaging, so I decided to blend the result of my 3nm Ha filter into the Lum and Red channels in this LRGB image. As you can see, there's quite a bit of detail within the nebula which is mainly from the Ha component of the image. It was taken with my Esprit 150 and represents just under 16 hours integration time. Alan LIGHTS: L:16, R:16, G:13, B:10 x 600s; Ha x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.

Thanks for the comment Gina. Alan

Thanks Wim - yes, it does not often appear, although it is often captured in wide field views of B22. Thanks - it's quite different from my normal output. The style of the image reminds me a bit of an old dark oil painting. Thanks for the comment Thanks Alan !

Thanks Mick

Here's one you don't very often - the reflection nebula IC2087, which is embedded in the dark nebula Barnard 22. Since reflection nebula's are normally blue, I'm not too sure why this one is orange(ish)....I guess it must be the combination of the light from the bright blue star (out of frame), which is makes the background blue/purple, interacting with the dark brown/red of the dark nebula. IC2087 is also known as the little flame which seems appropriate since the stars above it appear like sparks from a small fire. For those with keen eyes, you'll also see a small red blotch above the fire, this isn't a processing artifact but a Herbig-Haro object which is a patch of nebulosity associated with newly born stars. So, you get quite a few interesting features in this image which was taken with my Esprit 150 and represents just under 10hours integration time. Alan LIGHTS: L:12, R:15, G:12, B:20 x 600s, BIAS:100, DARKS:30, FLATS:40 all at -20C.

I find the best way to inspect collimation errors is to pick an individual star and then zoom in on it to inspect it in detail. What you should see is all the colours aligning, in your case the red channel is slightly misaligned. To explain a little further, if I select a star at the right hand edge of the frame I get the image below. The star should be blue but you have a red misalignment effect as shown below in this highly magnified image. Hope this helps ! Alan

Very good. I do like the colours ! In terms of points for improvements that you've asked for: on the core you might want to try using PI's HDR multiscale transform to see if you can obtain more detail. Select an area somewhat larger than the core as a preview, then apply HDR to only the preview using the settings of your choice. When you are happy with the result, run the script substitute with preview (under utilities). Your HDR core image with then be automatically incorporated into the main image (hopefully) without a noticeable join. I used this Adam Block technique on my own effort and managed to get good core results - see my album Deep Sky III. The other suggestion is that your red channel is not quite aligned to the other channels, you can see this quite clearly on the right hand side of the image. I presume this is due to a slight collocation error. To correct for this in post processing - in PI's (latest release) in star alignment try selecting thin plate splines as the registration model and then check the distortion checkbox. Alan

Thanks. Yes, I think its my favorite part of the image, although that central star is bright ! Alan

Thanks Olly. It will be interesting to see if this post encourages some more attempt at this object. Thanks, much appreciated ! Alan Many thanks for the comment. Alan

Vdb24 is a blue reflection nebula in the Perseus constellation which is embedded within the larger dark (reddish/brown) nebula LDN1442. It seems quite a rarely imaged object, I found only two examples on Astrobin and zero on SGL. It's quite an interesting image to process since the dark (brown/reddish) nebula tends to distort the star colours, particular the blue stars, pushing them towards the red end of the spectrum. It also has quite a few very bright blue stars, including one that acts to illuminate the reflection nebula itself. Anyway, here's my effort which represents just over 14 hours of integration time. The image is an LRGB and was taken with my Esprit 150. Alan LIGHTS: L: 30, R:13, G:21, B:21 x 600s, DARKS:30, BIAS:100, FLATS:40 - all at -20C.

Thanks for the comment Alan

Thanks Martin. Yes, the extra time definitely helped with the bubble definition, although I still struggled getting good star colours. I think I need more practice. Alan

I thought some of you might be interested in seeing an odd looking artifact in one of my recent images of the bubble nebula (see below). At first, I thought this was due to incorrect settings within Pixinsight's Winzorised stacking algorithm. However, on examining the individual subs everything was OK - no artifact, just a star. On closer examination of the individual subs, I noticed that the star sometimes appeared clearly and sometimes appeared hardly at all. So, I decided to see if the free ware program Aladin (https://aladin.u-strasbg.fr/ ) could identify the star. Plate solving the object in Pixinsight allowed me to locate the RA and DEC co-ordinates of the artifact (23 20 43.535, +61 14 43.54), after typing these into Aladin it turns out to be the variable star V*MOCas of Mira Cet type. Since I gathered the data over many months, I presume the star was varying over this period and hence confusing the stacking algorithm and creating the artifact. Alan

Thanks Giorgio - I'm pleased that you like it ! 😀 Thanks

In an effort to improve on my image of the Bubble Nebula from a few years ago, I decided that my existing data needed a longer integration time...... so at a total integration time of just over 26 hours here's the result. The image, taken with my Esprit 150, is an LRGB rendition with an Ha blend into the Red and Lum channels. I was particularly interested in seeing how much detail I could extract on the bubble itself, so I decided that it looks best cropped. Alan LIGHTS: L: 33, R: 27, G:27, B:23 x 600s, Ha:16 x1800s, BIAS:100, DARKS:20, FLATS:40 all at -20C.