wimvb

Thanks, Olly. Glad you like it. "Bold" befits this galaxy, unlike its close neighbour which is a lot subtler (/ more subtle??)

Clear nights are far between, and I'm not going to start a project that requires a long integration time. This is M82, plain and simple. I collected 6 hours RGB yesterday and combined it with 6 hours Ha which I collected more than a year ago, but never processed. This target needs no presentation, only technical details. As usual, I used the MN190 with ASI294MM camera. Optolong RGB filters and Baader 7nm Ha filter. 24 x 5 minutes exposures per filter for RGB, 93 x 4 minutes for Ha. Total integration time, 12 hours Processed in PixInsight

It seems other countries are following Starlink and Amazon. China has announced it's planning its own 13,000 satellite constellation. https://spacenews.com/china-to-begin-constructing-its-own-megaconstellation-later-this-year/ Who'll be next?

In Aladin ( https://aladin.cds.unistra.fr/AladinLite/?target=05 20 29.804-05 13 11.43&fov=22.94&survey=CDS%2FP%2FDSS2%2Fcolor ), based on the Sloan Digital Sky Survey, there are also two colours of dust in this area, the brownish related to HII and the gray/blue, which does not have a distinct identification. They may be at different distances from us, receiving light from different stars. Remember that for HII to emit its red colour, the gas must be illuminated by UV light from "nearby" stars.

In this image?

Now we do. And we can't unsee it. Great rework, Göran. If coming summer is as bad as the winter we've just had, there will be plenty of time to rework old images.

Great image, Olly "Mary" Penrice. 😉

29% doesn't seem a lot to me. Without any more details, it's difficult to isolate the problem. Have you posted this problem on the indilib forum?

You can make 2 luminance masters, one with just the best subs for detail (master 1), and one with all the subs for the faint stuff(master 2). You do a Linear Fit on them to get the same brightness. Then you extract layers from both and recombine lower number layers (the fine details) of master 1 with the higher number layers of master 2. This is similar to the technique used here: https://www.deepskycolors.com/archivo/2010/05/07/multi-scale-Processing--Revealing-very.html

It seems that you have about the same weather conditions as we have, good seeing, but poor transparency. I agree with Göran re version 2, it seems over-deconvolved, the first image is better. Adding luminance will help, if your conditions allow.

Excellent image, Rodd.

No imaging in March and April? Up here, spring is usually the best season for AP.

Much better, but not quite there yet. The secondary is not centered under the cheshire yet. In fact it almost looks like the secondary won't clear the cheshire. To get good alignment it's easier/necessary if you can see the edges of the secondary. The diagrams that @Enceladus Dan posted will help.

I don't have any experience with APP, but I wouldn't hesitate to buy PI if I didn't already have it. As the saying goes, "you get what you pay for". With PI you really get a lot for what you pay.

Fiddling in PI resulted in this

That's the way to go! I had a look at your data, and can only say that there's a lot of noise. My guess is that you have a fair amount of light pollution that just needs more data.

Not in my opinion, no. But it's a very powerful program, and for a beginner it's easy to get overwhelmed by its functionalities. Unlike a few years ago, there are now many youtube tutorials that will help you along the way.

Btw, the Bayer matrix on this sensor is RGGB, I believe. And as Vlaiv noted, do use FITS as output file type. Depending on the capture software you use, the Bayer matrix information will be stored in the FITS header, in which case the stacking software should be able to determine it.

Stacking takes care of deBayering, which the sofware does AFTER calibration, but BEFORE star alignment. Just enter the correct Bayersettings

If you look at the reflection in the secondary, you'll notice that it needs tilting until the whole primary is visible. Also, you need some tools, like a collimation cap, to get a more precise view. With just a camera pointing into the focuser tube, you can't really tell how well everything is aligned. The central screw on the secondary assembly is for moving the secondary up or down the tube. Be careful when adjusting it, or the secondary may come loose and fall down on the primary. Keep the scope horizontal when you collimate

Here's my attempt. There's some ifn coming through, but unfortunately also the residual of the amp glow

I just downloaded the fits image, and here is my first impression: Your darks are not correcting your lights the way they should. The ampglow from your camera (an ASI294??) is overcorrected. Are you sure that the darks match the lights in temperature, gain, offset and exposure time? You have half of M82 in your frame. I would crop that out. The image is still very noisy. You probably have light pollution and need more data to bring the noise down. I will process the image in PixInsight and get back with the results.

Thanks, Göran. Yes, there is some ifn in the lower right corner, but generally it seems very weak in this region of the sky.

Some 😉 AI systems used to be called "expert" systems, because they are very good at one thing, that which they were designed for. I think that the problem with Chat GPT (and possibly other similar AI systems) is that it isn't limited, and that we confuse style with content. The AI does write a good text, and it states in its own disclaimer that it is a language model. But its content is rubbish. I think we are (still) expecting too much from such a system, and that we can not rely on it to write factual text. Especially so when the content of such text is highly technical and based on limited data. It is obvious from the three examples that the output is a compilation of information of "similar" subjects, where the AI can't evaluate relevance properly.

Recently I've been imaging galaxy ngc 4041 in Ursa Major, and as I always try to add interesting information to my images, I tried something new. I let Chat GPT "describe galaxy ngc 4041" for me. Here's what it came up with: "As an AI language model, I can produce the description of the galaxy NGC 4041, but I cannot see it. Here's what I know: NGC 4041 is a barred spiral galaxy located in the constellation of Crater, roughly 50 million light-years away from Earth. It has a unique shape with a central bar-shaped structure connecting to spiral arms that are twisted in an unusual way. Its bulge of stars at the center is believed to contain a massive supermassive black hole. NGC 4041 is not an active galaxy but it was once recorded to produce supernovae. It also houses many star clusters and nebulae scattered throughout its spiral arms, indicating active star formation. Overall, NGC 4041 appears to be a fascinating object of study for astronomers and astrophysicists." When I then asked instead to "review galaxy ngc 4041", it came up with this: "As an AI language model, I don't have the ability to visually observe an astronomical object like the galaxy NGC 4041, but based on available data and research, here's a review: NGC 4041 is an intermediate spiral galaxy located in the Ursa Major Constellation, and it stands out for its asymmetrical shape, which is thought to be caused by a recent interaction with another galaxy. The galaxy's distance from Earth is estimated to be about 75 million light-years. Studies of NGC 4041 show that it has a somewhat bizarre composition, with unusually high concentrations of cold molecular gas and dust, which are responsible for the formation of new stars. Researchers believe that this process is ongoing, and that the galaxy is still actively evolving. The central region of NGC 4041 is also notable for its bright nucleus, which emits a high level of radiation and has been classified as a Seyfert galaxy. Seyfert galaxies are known for their active galactic nuclei, which are believed to be powered by supermassive black holes. Overall, NGC 4041 is an interesting galaxy to study due to its peculiar composition and ongoing evolution. Its asymmetrical shape and bright nucleus make it a popular target for observation among astronomers." I then asked the same AI to "write an essay about galaxy ngc 4041", resulting in this: "Galaxy NGC 4041, also known as Arp 20, is a beautiful spiral galaxy located in the constellation of Leo. It was discovered in 1784 by Sir William Herschel, a famous astronomer from England. NGC 4041 is classified as a Seyfert galaxy, meaning it has an active galactic nucleus that emits high levels of energy. NGC 4041 is unique in many ways. It has a bright, active central region with a bright nucleus, surrounded by a prominent ring of gas and dust. The ring is believed to be a result of gravitational interactions with other galaxies in its vicinity. This interaction has caused the gas and dust in the outer regions of the galaxy to fall towards the nucleus, forming the ring. NGC 4041 also has a prominent bar-like structure in its central region, which is believed to play a crucial role in the formation of stars. The galaxy is about 70 million light-years away from the Earth and has a diameter of approximately 120,000 light-years. It has a relatively low mass compared to other large galaxies, with an estimated mass of around 16 billion times that of the sun. NGC 4041 is about half the size of our own Milky Way galaxy and contains around 200 billion stars. The active galactic nucleus in NGC 4041 is believed to be fueled by a supermassive black hole at its center. This black hole has a mass estimated to be around 12 million times that of the sun and is actively accreting matter from its surroundings. As matter falls towards the black hole, it heats up and emits high-energy radiation, making NGC 4041 one of the brightest Seyfert galaxies known to date. NGC 4041 has been the subject of many scientific studies over the years, particularly those focused on understanding the formation and evolution of galaxies. Its proximity to the Earth and active nucleus make it an excellent object for studying the physics of accretion and the properties of active galactic nuclei. Astronomers have also used NGC 4041 to study the dynamics of barred spiral galaxies and to investigate the role of interactions between galaxies in galaxy evolution. In conclusion, NGC 4041 is a fascinating object that has much to teach us about the formation and evolution of galaxies. Its unique properties make it an essential target for astronomers in their quest to understand the universe around us. As technology improves and our knowledge of the cosmos expands, we can expect to learn even more about this enigmatic galaxy in the years to come." Methinks AI is more A than I. (Note, Arp 20, or ugc 3014, are interacting galaxies in the constellation Taurus) Btw, here's the link to my image, together with my own text. https://stargazerslounge.com/topic/408033-heres-a-first-ngc-4041-with-extended-disk/