Astrophotography – PekDar – Astrophotography Engineering

Perun powerbank crosing borders

PekDar — Sun, 17 Mar 2024 14:16:52 +0000

Perun powerbank crosing borders

and going abroad to their new owners – Singapore.
I never thought that Perun could bring interest among foreign colleagues astrophotographers.

I’m really happy. It is worth being 100% committed and persistent in pursuing goal. It is worth having a plan and implementing it consistently to celebrate such moments like this.The Perun project required money, a lot of work and time, which I will never get back, but the joy it gaves me is priceless.

PERUN - two sets ready to ship

Prun with SkyWatcher mount

Perun with CEM40

Astroberry power supply – DIY

PekDar — Sat, 01 Apr 2023 20:28:26 +0000

Designed by me, the Astroberry power supply delivers 84 W of power, which is enough even when I connect additional devices to all four USB ports that are powered from those ports. The power supply’s output voltage is the standard 12 VDC.

The Raspberry Pi 4, which is the “heart” of Astroberry, is normally powered with 5 VDC. My own Astroberry design is powered by 12 VDC via an appropriate voltage converter; I’ll skip further details for now — that’s a topic for a separate article on my website, which is slowly taking shape. Its compact size allows me to take it anywhere.

I can and do use the built power supply to power any astrophotography rig. For almost a year it has worked very well every time I use it. So far it has never let me down.

PSU technical specification – Astroberry power supply – DIY

Power input

mains power supply 230[AC],
standard computer power socket,
current protection 630[mA],
anti-interference protection,
two-state rocker switch,

Power output

voltage: 12 [V] DC
max. current: 7 [A]
current protection: 7 [A]
electrical and electromagnetic interference protection
LED power status
2-pin male power socket, compatible with PERUN power socket and PERUN II, the same power patch cords of devices can be used.

The Leo Triplet (M66 Group) – A Gravitational Dance of Three Galaxies

PekDar — Tue, 03 Jan 2023 11:31:36 +0000

The Leo Triplet – A Cosmic Laboratory

Is more than just a popular astrophotography target in the spring sky. It is a textbook example of tidal interactions between galaxies. Located approximately 35 million light-years from Earth, the group consists of three large spiral galaxies: M65, M66, and NGC 3628, all fitting within a single field of view, creating a spectacular frame.

Source: https://en.wikipedia.org/wiki/Leo_Triplet

Detailed Object Analysis

M65 (NGC 3623): In contrast to its neighbor, M65 appears “calm.” It is a tightly wound spiral that, despite the proximity of other objects, has maintained a relatively intact disk structure, although a trained eye might spot a slight warp at the edges.

M65 – is an intermediate spiral galaxy about 35 million light-years away in the constellation Leo, within its highly equatorial southern half. It was discovered by Charles Messier in 1780. With M66 and NGC 3628, it forms the Leo Triplet, a small close group of galaxies. The galaxy is low in dust and gas, and there is little star formation in it, although there has been some relatively recently in the arms. The ratio of old stars to new stars is correspondingly quite high. In most wavelengths it is quite uninteresting, though there is a radio source visible in the NVSS, offset from the core by about two arc-minutes. The identity of the source is uncertain, as it has not been identified visually, or formally studied in any published papers.

To the eye, M65’s disk appears slightly warped, and its relatively recent burst of star formation is also suggestive of some external disturbance. Rots (1978) suggests that the two other galaxies in the Leo Triplet interacted with each other about 800 million years ago. Recent research by Zhiyu Duan suggests that M65 may also have interacted, though much less strongly. He also notes that M65 may have a central bar—it is difficult to tell because the galaxy is seen from an oblique angle—a feature which is suggestive of tidal disruption.

Source: https://en.wikipedia.org/wiki/Messier_65

M66 (NGC 3627): The largest and brightest of the group (9.0 mag). The image reveals a clear asymmetry in its spiral arms. This is a direct result of gravitational “tugging” by its neighbor, NGC 3628. The core is offset, and the dust structure is disturbed – evidence of a turbulent dynamic past.

Huge amounts of dust and numerous bright star clusters are found along the galaxy’s vast spiral arms.

Four supernovae have been observed in this galaxy so far: SN 1973R, SN 1989B, SN 1997bs.

Source: https://en.wikipedia.org/wiki/Messier_66

NGC 3628 (The Hamburger Galaxy): Seen perfectly edge-on. Its most characteristic feature is the massive dust lane cutting across its equator. This galaxy has suffered the most from the gravitational encounter – its disk is visibly puffed up and distorted at the extremities. The NGC 3628 – also known as the Hamburger Galaxy or Sarah’s Galaxy, is an unbarred spiral galaxy about 35 million light-years away in the constellation Leo. It has an approximately 300,000 light-years long tidal tail. Along with M65 and M66, NGC 3628 forms the Leo Triplet, a small group of galaxies. Its most conspicuous feature is the broad and obscuring band of dust located along the outer edge of its spiral arms, effectively transecting the galaxy to the view from Earth.

Due to the presence of an x-shaped bulge, visible in multiple wavelengths, it has been argued that NGC 3628 is instead a barred spiral galaxy with the bar seen end-on. Simulations have shown that bars often form in disk galaxies during interactions and mergers, and NGC 3628 is known to be interacting with its two large neighbors.

Source: https://en.wikipedia.org/wiki/NGC_3628

Engineering Challenge

The Tidal Tail The main challenge in processing this data is not just showing the galaxies, but preserving detail in the dark dust lane of NGC 3628 while avoiding overexposure of the M65 and M66 cores. Deep exposure (long integration time) allows, under favorable conditions, the capture of the faint “tidal tail” extending from NGC 3628 – a stream of stars ripped from the galaxy by the gravity of M66 approximately 800 million years ago.

Technical Summary

The image demonstrates the morphological diversity of spiral galaxies depending on their inclination angle relative to the observer: from “face-on” (M66), through an intermediate angle (M65), to “edge-on” (NGC 3628).

Lights taken at 14/15-3.2020 near Bielsko-Biała city.

Composition: Astro Pixel Processor v1.8,
Processing: GIMP v2.10.30 + plug-ins (Linux),
Lights: 44 x 180[s] ISO-800,
Darks: 15 ISO-800,
Bias: 20 ISO-800

IC 1805 – Heart Nebula

PekDar — Fri, 01 Oct 2021 16:06:37 +0000

7500 light years away from Earth and is located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It is an emission nebula showing glowing ionized hydrogen gas and darker dust lanes.

The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered. The nebula’s intense red output and its morphology are driven by the radiation emanating from a small group of stars near the nebula’s center. This open cluster of stars, known as Collinder 26 or Melotte 15, contains a few bright stars nearly 50 times the mass of our Sun, and many more dim stars that are only a fraction of our Sun’s mass.

Dimmed stars I’ve made with GIMP software.

IC 1805 – Heart Nebula – dimmed stars

Source: https://en.wikipedia.org/wiki/Heart_Nebula

Technical information

Date: 12.2020
Composition: APP,
Processing: APP + RT + GIMP + add-ons (Linux),
Total exposure time minus defective light frames: 4h 36min.,
Lights: 238,
Calibration frames: Flats, Bias, Darks

M45 – Pleiades: two captures of one object + complete guide

PekDar — Sun, 06 Dec 2020 12:37:27 +0000

M45 Pleiades (Seven Sisters) is one of the most iconic DSO targets — a young open cluster dominated by hot B‑type stars embedded in a blue reflection nebula. The distance is about 444–445 light‑years, the total brightness ~1.6 mag, and the apparent size ~2° (~4 Moons). It sits in Taurus, best observed from late autumn to winter. The cluster is dominated by hot blue and luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from the formation of the cluster, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing. Object: key facts RA/Dec (J2000): ~03h 47m, +24° 07′ (Taurus). Distance: ~444–445 ly (Gaia/HST; literature varies slightly). Age: ~100 Myr (range 75–150 Myr depending on method). Size & mag: ~2° across; ~1.6 mag. Reflection nebulae: NGC 1432 (Maia) and NGC 1435 (Merope); the dust is unrelated to the cluster’s formation — the stars are passing through an interstellar cloud. Evolution: the cluster will disperse in ~250 Myr due to galactic interactions. New research (2025): Using TESS + Gaia, astronomers identified a Greater Pleiades Complex — a dispersed family of >3,000 related stars spanning ~1,900 ly, tripling the known membership context. This doesn’t change the visual M45 appearance but reframes cluster dynamics. Two captures — what they show Capture A Integration: 5 h 56 min net (several sessions; ISO 1600 + 1000; one session without Flats). Processing: APP + RT + GIMP; multi‑session merge → small mosaic; harder calibration but greater dynamic range and dust detail around Alcyone/Maia/Merope. Composition: Astro Pixel Processor, Processing: RT + GIMP + plug-ins (Linux), Total exposure time minus defective lights: 5h56 min. ISO 1600 + 1000 Calibration frames (one missing session): Flat, DarkFlat, Bias Capture B (multi‑session mosaic, 2019) Shows a different composition and nebulosity emphasis (e.g., Merope Nebula / NGC 1435, or the Atlas–Pleione pair in the “handle”). Useful to compare chroma/halo control around brightest stars. Nebula context per star: NGC 1432 (Maia), NGC 1435 (Merope), vdB 23 (Alcyone); tiny IC 349 near Merope. Computer simulations have shown that the Pleiades were probably formed from a compact configuration that resembled the Orion Nebula. Astronomers estimate that the cluster will survive for about another 250 million years, after which it will disperse due to gravitational interactions with its galactic neighborhood. Astrophotography tip M45 is easy to overexpose. Use shorter subs for wide fields (halo control) or longer integration at higher focal length to pull delicate reflection dust. Prefer no LP filter; balance color carefully; stretch gently. How to find & when to shoot M45 sits in Taurus; from mid‑northern latitudes it’s best in December (high altitude, good contrast). It’s bright enough to be seen with the naked eye even under moderate light pollution. Curiosities “Golden Gate of the Ecliptic”: with the Hyades, Pleiades frame a classic ecliptic gateway. Subaru: in Japanese the cluster is Subaru — hence the car logo. Mythology: the Seven Sisters (Alcyone, Maia, Merope, Electra, Taygeta, Celaeno, Sterope), with Atlas and Pleione. References: https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-45/ https://en.wikipedia.org/wiki/Pleiades https://www.astropixels.com/openclusters/M45-A01.html https://messier.lamost.org/seds/seds.org/messier/en/more/m045_tab.html https://science.nasa.gov/missions/tess/nasas-tess-spacecraft-triples-size-of-pleiades-star-cluster/

Astro Pixel Processor – Basic Tutorial (Step‑by‑Step Guide)

PekDar — Thu, 03 Dec 2020 17:22:56 +0000

The main goal of this Astro Pixel Processor tutorial is to provide you, with the ability to quickly stack photos using the APP program, in the shortest possible time with minimal the baggage of knowledge need. I share with you what I know. I have gained experience using the APP program on my own. Remember that each photo of collected lights is different and the examples below, will not necessarily work for your collected photo lights. You should always look for the optimal settings and solutions for each lights. Please, note that I am not the Developer of the APP (Astro Pixel Processor), but only I’m user like you. I don’t know answer to every question that bothers you. Nor am I any representative of the APP Developer or its publisher. APP provides flexible stacking algorithms compared to DSS, supports mosaics, gradient correction, and multi‑session integration. A great balance between simplicity and power. Why choose APP? APP stands out compared to other programs (e.g., DSS, PixInsight) thanks to: Flexible stacking algorithms (multi‑session integration). Support for mosaics and gradient correction.Intuitive interface and automatic calibration. It’s a great balance between simplicity and power – perfect for astrophotographers who want more than DSS without the steep learning curve of PixInsight. APP Preconfiguration Click on CFG button From the drop-down list, set the amount of RAM you want to allocate for use with APP. The rule is simple, more = better. After setting the desired amount of memory, click on OK and that’s it. Lights processing – ATIK Horizon CMOS color camera The Light files are made with “ATIK Horizon color camera” with the filter used in the optical path. We will be processing a photo from a single session so, the following settings of individual tabs are in the given configuration. Run the APP program (my version is 1.081). Shortly after starting a window will appear in which you have to enter the path, to the working directory. Preferably the same directory that contains Lights files for stacking. On the left side of the program window, under the tabs, uncheck two options: • Multi-Channel / Filter processing • Multi-Session processing In the Enter DeepSky object name: text box, enter the name of the object that was photographed. After selected files are loaded, the counter for Lights will change from 0 to the number, of files that we have indicated for loading. In my example, there are 89 files. 0) RAW/FITS ATTENTION! if your photo material was made with a camera, set pattern to supported. pattern set to supported turn off force Bayer/X-Trans CFA Click on the tab 0) RAW / FITS. It is very important to know the sensor type of the camera, on which the photos were taken. In the case of ATIK Horizon it is GRBG and such should be set for pattern from the list of available types. We enable the force Bayer / X-Trans CFA option, the other options are not changed. 1) LOAD Go back to the 1) LOAD tab and click the Light button to load the Light photo files. Notice the counter with status 0 to the right behind the buttons. In the file selection window, select the files you want to load and click the Open button. After the selected files are loaded, the counter for Light will change from 0 to the number of files, that we have indicated for loading. In my example, there are 89 files. At the very bottom of the program window, there is a preview of the list of loaded files. It is worth reading the description of each column – helpful and necessary information. Now repeat the process of loading files for the types: Flat, Dark, DarkFlat and Bias. You can skip all calibration frames or the missing type, then you should take into account that the quality of the photo will be worse. If you already have previously generated MasterFlat, MasterDark, MasterDarkFlat, MasterBias and BadPixelMap files for the Flat, Dark, DarkFlat and Bias file groups, that you want to use, you can load them now and skip the Master… regeneration process it saves a lot of time in the whole photo stacking process. WARNING! Remember that Master files generated from a given group belong to the Lights files photo session. The exceptions to this rule are BadPixelMap and MasterBias. 2) CALIBRATE Plenty of options available here, you can get a little overwhelming. We will be focusing only on a few specific options following my example. I think that the following description will be applicable in most cases of the collected lights files. Most options have a default value that we won’t change except for a few. Turn on: scale MasterDarkFlat scale MasterDark Now it’s time to generate Masters calibration files. Click on the create Masters & assign to Lights button. WARNING! – If you have already loaded Master calibration files, click the (re-) assign Masters to Lights button, this will assign the lights files to the calibration files. APP – Calibration frames options After creating the Master photos, you can see what they look like. This is very important. The quality of stacked the final photo depends on the quality of Master files preparation. In the file view list (at the bottom of the program window), you will see the Master files created. To view the mentioned files, just click 2x LMB on their name to load them to preview. Below is a sample of how my Master files look like. They are generally not bad and they are suitable as a calibration files for lights files. BadPixelMap – zoom 80% MasterDark – zoom 80% 3) ANALYZE STARS We do not change the default value. 4) REGISTER Most of the default options are set correctly and we will not change them. Let’s go to the next tab. 5) NORMALIZE Configure the individual options as described below. It is possible that some options, are already set by default as defined

M8 Lagoon and M20 Trifid Nebulae

PekDar — Thu, 26 Nov 2020 20:15:21 +0000

M8 Lagoon Nebulae is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region. The Lagoon Nebula is estimated to be between 4,000-6,000 light-years away from the Earth.

StarStaX and Star Trails – Photo Stacking and Gap Filling

PekDar — Fri, 06 Nov 2020 20:36:41 +0000

Why StarStaX? In modern landscape astrophotography, creating Star Trails by taking hundreds of shorter exposures is preferred over a single, hours-long shot. This approach has a key practical advantage: if a flashlight shines into the lens, a car passes by, or the tripod gets bumped, you simply discard that single frame rather than losing the entire night’s work. To combine these frames into a final image, StarStaX is the go-to free software. It is lightweight, fast, and dedicated specifically to this task. How It Works? The “Lighten” Mode StarStaX does not sum up light in the traditional way (which would result in an overexposed, white image). It uses the “Lighten” blending mode. The software analyzes every pixel across all images and selects only the one with the highest brightness value for the final output. This ensures bright stars “overwrite” the dark sky background. Noise in the shadows does not accumulate, keeping the final image clean. The Gap Problem and “Gap Filling” There is always a tiny delay between shots (time for the camera to write the file to the card). As a result, after stacking, star trails might look like dashed lines (“beads on a string”). StarStaX solves this with the Gap Filling feature. The algorithm analyzes the end of a star trail on one frame and the beginning on the next, mathematically interpolating the missing segment. The result is perfectly smooth arcs, even if your camera has a slower buffer. “Comet Mode” Option An interesting addition is the Comet Mode. The software simulates a gradual fading of the star trail, adding dynamics and a sense of motion to the image, resembling a meteor shower or comets. Creating Star Trails is one of the most spectacular astrophotography techniques. In this comprehensive step-by-step tutorial, you will learn how to stack a series of individual frames into one stunning image using the free StarStax software. This guide includes the essential step of RAW file conversion to a lossless 16-bit PNG format using RawTherapee, and it’s friendly for Linux users (as it uses free, multi-platform tools). Capturing Star Trails in a photo is not to difficult task. There are several schools to do this. The Internet has many descriptions and videos on how to do this. I think I’ll never become a YouTuber, personally I prefer to create a document or simple instruction that describe the whole ho-to process in clear technical language and this was what it guide me during preparation this description. Remember that each photo is different and the following examples, will not necessarily work for your photo light collection. My best practice is to always look for the optimal settings and processing solutions for each photo separately. It can be also your best practice. English is not my native language. I wrote this description with my best I can, I will be grateful for any support by e-mail with information, where I made a mistake to correct it. I do not consider myself as an expert with described subject. I think I still have a lot to learn and find a way, to get an better final effect than the one presented in the photo below. Together we will go through with three main steps. Preparation of the source light frames, eg in the RawTherapee program. It can be any other program you like it to use or learn RawTherapee for self-discovery. Stacking the light frames together using the StarStax program, Complete the photo using the available functions in StarStax. 1. RawTherapee – RAW Conversion and Light Frame Preparation StarStax version 0.71 cannot handle .RAW files. Before we join the light frames together, we have to convert the .RAW type of the collected light files, to the .PNG 16bit or TIFF 16bit type. It can’t be a type, e.g. JPG or other type, that generates quality losses. I’ve chosed the .PNG 16bit type. Lets go for actions. Start the RawTherapee and go to the File Browser tab, to load light frames by clicking on the appropriate file folder. Click on the first light frame and adjust its parameters (brightness, contrast, color saturation, exposure, etc.) to your preferences. The options available on the image processing tabs, are available for this purpose. Experiment to get to know them and learn how to use them. Each processed photo has its own profile of changes. This profile should be copied and placed / pasted on the remaining photos in the queue, so that each photo has the same changes – the nature of the author of the processing. In the top preview bar, the first photo is highlighted with a colored frame – the active photo. Right-click on the active photo and select Processing profile operations → Copy from the context menu to copy the profile. Now, we will apply the copied profile to the remaining photos. On the top photo preview bar, left-click any photo, press CTRL + A to select all photos. Then right-click on any photo and select Processing profile operations → Paste. The profile will be applied to all photos almost at once. Depending on the number of photos and the processing power of your computer, the change process may take a little longer. The last step is to export the modified photos to the .PNG 16bit type. Select all photos in the same way as we did in the previous step (CTRL + A). Right-click on any photo and select Put to queue from the context menu. On the left side of the program window, click on the Queue [..] tab to change the view to the export queue. Set Output Location to Save to folder to specify the destination directory where the .PNG output files will be saved. Set File Format to PNG (16-bit). Now click the OFF switch and change it to ON to start the photo export process. Now is the time for coffee / tea / whatever you prefer. The photo export process will take a while. When it is finished, go

M42 (Orion Nebula): From Dark Dust to the Blinding Trapezium

PekDar — Sat, 12 Sep 2020 22:02:41 +0000

M42 Orion Nebula

The Nearest Nursery M42, the Great Orion Nebula, is the undisputed queen of the winter sky. Located just 1344 light-years away, it is the closest region of massive star formation to Earth. Due to its proximity and brightness (visible to the naked eye), it allows for a detailed analysis of matter creation and destruction processes that remain invisible to us in other galaxies.

This article presents two different approaches to the same object, revealing its complex nature: the surrounding dark dust and the energetic heart.

The Dust Cloak (Outer Structures)

Looking at the deeper parts of the image, we see that M42 is not suspended in a void. It is part of the gigantic Orion Molecular Cloud (OMC-1).

Dark Nebulae: The gray, “dirty” structures surrounding the bright center are dense interstellar dust. This is the building material that has not yet been ionized by the stars.
Context: Here, we witness the dynamic battle between light and matter. Radiation from the center “pushes” and sculpts these clouds, creating shockwaves within the medium.

The Nebula Engine and H-alpha

The second image and next reveals completely different physics – ionization and the core.

Red Color: The dominant red is the signature of hydrogen (H-alpha line). It indicates high energy in this region.
The Trapezium Cluster (Theta-1 Orionis): At the very center, often overexposed in amateur images, lies a cluster of young, massive stars – the Trapezium. These four main stars (A, B, C, D) are the “engine” of the entire nebula. Their powerful UV radiation illuminates the gas over hundreds of light-years and has excavated the visible “cavity” in the center of the cloud seen in the image.

Technical Challenge

Dynamic Range (HDR) M42 is one of the most difficult objects to expose correctly due to its extreme dynamic range. The brightness difference between the core (Trapezium) and the outer dust loops is so vast that a camera sensor cannot capture both in a single exposure. To show the nebula’s center (rather than a blown-out white patch) alongside faint outer veils, it is necessary to use HDR (High Dynamic Range) techniques or layer masking, blending short exposures (for the core) with long ones (for the background).

Source: https://en.wikipedia.org/wiki/Orion_Nebula

First photo taken on October 2019.

Composition: APP (13 frames)
Processing: RawTherapee and GIMP v2.10.18 + add-ons (Linux)
Lights: 13 x 600[s], ISO-400;
Bias, Flats

Second and next photos:

Composition: Astro Pixel Processor v1.078,
Processing: GIMP v2.10.14 + plug-ins and RawTherapee 5.6,
Lights: 21 x 60[s] ISO 1600,
Flats: 20, ISO-1600,
Darks: 9, ISO-1600,
Bias: 20, ISO-1600

M101 / NGC 5457 – Pinwheel Galaxy

PekDar — Sat, 30 May 2020 21:26:26 +0000

M101 NGC5457 Pinwheel Galaxy

also known as the Pinwheel Galaxy, is a spiral galaxy in the constellation Ursa Major with a faint nucleus and very well-developed spiral arms. Its apparent magnitude is 7.9. The galaxy spans 170,000 light years in diameter and has a mass of about 180 billion solar masses. It lies approximately 21 million light years away.

In this galaxy, four supernovae have been observed to date: SN 1909A, SN 1951H, SN 1970G, and SN 2011fe. Along with other, fainter galaxies, M101 forms the M101 galaxy group. The influence of nearby galaxies has distorted M101’s shape and stretched its gas clouds. A close flyby with a neighboring galaxy (most likely NGC 5474) near M101 about 250 million years ago also contributed to enhanced star-forming activity. The northeastern arm of the galaxy contains a greater concentration of young, blue stars. It is visible from Poland throughout the year.

Source: https://en.wikipedia.org/wiki/Pinwheel_Galaxy

Photos taken on: March 2019.

Stacking: APP (only 3 best Light frames + Flats + Bias)
Postprocessing: GIMP v2.10.14 + add-ons (Linux)
Lights: 3 x 237 [s], ISO-1000;

M101 / NGC 5457 – Pinwheel Galaxy

A good example showing how a coma mirror can break a nice picture.

M101 / NGC 5457 – Pinwheel Galaxy (crop)