Siril 1.2.2

We’re delighted to announce that Siril 1.2.2 is now available. Many bugs have been fixed compared to version 1.2.1 released last year, and we hope that version 1.2.2 will be as stable as possible. List of fixed bugs (since 1.2.1) Removed background extraction samples after using it in script (#1265) Fixed catalog parser problem with negative declination (less than 1°) (#1270) Fixed weighting by number of stars during stacking if number of stars is the same accross the sequence (#1273) Improved mouse pan and zoom control to enable one-handed operation (!
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New ZWO Seestar script and tutorial

We are pleased to announce the release of a script and tutorial dedicated to Zwo’s new All-in-One telescope, Seestar. The tutorial explains step-by-step how to use the script, and then how to process the stacked image. The proposed script has been designed to automatically pre-process the raw images recorded by the Seestar and give the best image, automatically. We hope it will meet your expectations. To find out how, click here .
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Siril 1.2.1

We are pleased to announce that Siril 1.2.1 is now available. Many bugs have been fixed compared to the 1.2.0 release last year, and we hope that version 1.2.1 will be as stable as possible. List of known bugs None for the moment, fingers crossed. List of fixed bugs (since 1.2.0) Fixed Anscombe VST noise reduction option for mono images Fixed HEIF import (#1198) Fixed Noise Reduction Anscombe VST bug with mono images (#1200) Fixed problems with Fourier Transform planning > Estimate (#1199) Fixed data initialisation bugs in copyfits() and RGB compositing tool Fixed exported x-column for lightcurves when Julian date is not selected (#1220) Fixed sampling tolerance for astrometry which was incorrectly read (#1231) Allowed for RA/DEC to be sorted in PSF windows (#1214) Added SET-TEMP as valid FITS header to be saved (#1215) Added configurable color for background extraction sample and standard annotations (#1230) Fixed argument parsing error in makepsf (!
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Siril 1.2.0

We are delighted to inform you that Siril 1.2.0 is now available. Many bugs have been corrected since the previous release candidate, making this new version ready to become the final version. This version doesn’t bring anything new compared to version 1.2.0-rc1, but it does include a large number of bug fixes. In fact, as the list of users grew ever larger, so did the number of bug reports we received, enabling us to fix a large amount of issues.
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Siril 1.2.0-rc1

We are pleased to inform you that Siril 1.2.0rc1 is now available, only a few weeks after the release of beta1. Many bugs have been fixed since the previous beta, which makes this new version more stable and reliable. However, we remind you that the release candidate version of the software is an intermediate stage of development that precedes the final version. It should be noted that a release candidate may contain bugs, unfinished features and stability issues.
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Siril and Telescope.Live Launch New Tutorial Series

We are excited to share that Telescope Live, the online platform dedicated to astrophotography and remote imaging, has created a new video tutorial series for Siril, available for free for anyone. The 6 videos, totaling 39 minutes, are specially targeted at beginners. They cover many operations required to transform a raw dataset into a beautifully processed image. Telescope Live operates very high quality telescopes under the best skies of both hemispheres and provides a huge number of pictures in their archive, yet at an affordable price.
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Siril 1.2.0-beta2

We are pleased to inform you that Siril 1.2.0-beta2 is now available, only a few weeks after the release of beta1. Many bugs have been fixed since the previous beta, which makes this new version more stable and reliable. However, we remind you that the beta version of a software is a first version of the software that is still under test and development. It is made available for feedback and further testing before the final version is released to the public.
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Siril 1.2.0-beta1

A little more than a year ago, we released version 1.0.0 of Siril. This version number, highly symbolic, symbolized the age of maturity of a software that we believe had become stable and powerful. Since then, many updates came to improve little by little this version 1.0 by fixing many bugs and by bringing small improvements. In parallel to the development of this so-called stable branch, we have continued to intensively develop new features, resulting in profound changes.
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Bug Fix for MacOS Ventura users

MacOS Ventura is the thirteenth major version of macOS, released recently. Currently, Siril cannot be executed correctly on it because it is impossible to use the mouse on the application. This bug, which is very annoying, is caused by low-level changes in Ventura that affect GTK, the library that manages the graphical interface of Siril. And all applications using GTK3 are affected by this bug, namely GIMP v2.99, RawTherapee, Inkscape, Darktable and many others…
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Siril 1.0.6

While version 1.0.5 could be the last available version of the 1.0 branch, it turns out that some annoying bugs have been reported and needed to be treated as a priority. Siril 1.0.6 is therefore made available for bug fixing purposes only. Indeed, the development of version 1.2.0 is in full swing and currently takes us a lot of time. We also take the opportunity of the release of this version, on October 18th, to wish a happy birthday to Cécile who has had her hands in the code of 1.
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Siril 1.0.5

Shortly after the release of version 1.0.4, last week, we are forced to make a fix and release Siril 1.0.5 much earlier than expected. Indeed, we found a bug introduced in the previous version when we had fixed a bug. Sometimes, errors compensate and don’t show up, but when you fix one, the other one shows up. This is exactly what happened here. This bug is critical and causes a shift of 1 pixel in x and y after a registration of images on which there was a meridian flip.
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Siril 1.0.4

It’s back to school time, and with it, comes a new version of Siril: version 1.0.4. This is one of the last (if not the last) of the 1.0 branch. This version is mainly a stabilization version, but it still contains a small new feature in the tool introduced in the last update, the generalized hyperbolic transformation. For more information please read on. Downloads # Siril 1.0.4 is distributed for the 3 most common platforms (Windows, MacOS, GNU / Linux).
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Siril 1.0.3

Before the month of June comes to an end, we had to release a new version in order to keep the cruising rhythm started after the release of version 1.0. Downloads # Siril 1.0.3 is distributed for the 3 most common platforms (Windows, MacOS, GNU / Linux). Check out the downloads page. But of course, as Siril is a free software, you can build from the sources, available through the installation page.
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Siril 1.0.2

Keeping up on the fantastic pace of one release per month, we are pleased to announce the release of Siril 1.0.2. This is once again a stabilisation version and a continuation of 1.0.1. We recommend you update to benefit from the bug corrections and new features described in this page. Downloads # Siril 1.0.2 is distributed for the 3 most common platforms (Windows, MacOS, GNU / Linux). Check out the downloads page.
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Siril 1.0.1

One month after the release of Siril 1.0.0 (first stable version), we are pleased to announce the release of Siril 1.0.1 which stabilizes this version even more. Indeed, although the development of the 1.2 branch is particularly active, we decided to maintain a 1.0 branch in order to provide users with a follow-up of this first stable version. Downloads # Siril 1.0.1 is distributed for the 3 most common platforms (Windows, MacOS, GNU / Linux).
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Siril 1.0.0

10 years have passed since branch 0.9 restarted the then-dropped development of Siril. So we are extremely proud, happy and thrilled to release Siril 1.0.0 for download. This version is the result of a period of hard work started in 2020 and we hope it opens the beginning of a new era. Today, Siril team consists of 3 devs, the historical duo working under GNU/Linux environment, while the last team member works under Microsoft Windows, which has helped a lot stabilizing Siril behavior for this OS.
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Enough with dark flats

(…Or flat darks or whatever you call them) More and more, we see the term master dark flat all over the forums. These are supposed to replace the biases that are usually used in the standard preprocessing of astronomical images. We read that the result is better using a dark flat (shot with the same exposure time as the flats) than with standard biases. But is this really the case? Why such a frenzy for a master image that no one was talking about not so long ago?
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Siril 1.0.0-rc2

This version is a stabilization of the rc1 version, the new features are presented in detail here . We invite you to read this page carefully in order to know the implemented functions. However, we have made a short video explaining a bit how to use the improved plotting feature: Your browser does not support the video tag. Downloads # Siril 1.0.0-rc2 is distributed for the 3 most common platforms (Windows, MacOS, GNU / Linux).
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Siril 1.0.0-rc1

This is the first release candidate of the 1.0.0 version. It comes with some new features and many bug fixes compared to the previous beta version (, and contain all features that will be present in the final version. From now, we will focus on bug fixes in order to release as soon as possible the 1.0.0 version. This version also marks the arrival in the development team of Cécile (alias Cissou8) who is the author of a large number of improvements and who works on Windows!
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June 23rd, release udpate # Due to some bug reports with 0.99.10 version, we’ve decided to release this patched version. Fixed star detection with resolution < 1.0 Fixed interpolation issue in global registration Fixed timestamp issue with glib < 2.66 New MAD clipping algorithm The version # This is the fourth beta of the upcoming version 1.0. It comes with some new features and many bug fixes compared to the previous beta version (0.
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February 13rd, release udpate # Due to a crash with some FITS files of the 0.99.8 version (generally coming from ASIAIR system), a bug fix was quickly released under the version. We encourage everyone to update their software, even if Siril says that everything is up to date. The release # This is the third beta version of the upcoming 1.0 version. It comes with many improvements and bug fixes over the second beta (0.
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Siril 0.99.6 (1.0.0 beta2 testing)

One month after the release of the first beta version of Siril 1.0, which was largely adopted and praised by users, we are releasing a second beta version, with number 0.99.6. It fixes important issues that were found in the previous release, 0.99.4, thanks to the kind feedback of our community. It has already been tested by many users and should work in most cases. Remember this is a beta version, but we consider it already better than the previous stable version, the 0.
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What’s new in Siril 0.99.4

Siril 0.99.4, available here , has introduced a lot of new features. In this post, we have listed the highlighted ones. 32-bit native # The most important and especially the most awaited change is the switch to native 32-bit floating point for all calculations. The default FITS format is now of type TFLOAT. The files are therefore twice as large in size as before and the memory used is also twice as large.
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Siril 0.99.4 (1.0.0 beta testing)

We think it is time, time to release this new version for beta testing. Since the last stable version, the 0.9.12, more that 1400 commits were pushed to our repository, more than 66 000 new lines of code were added. A lot of new developers helped us in optimization, new features and bug fixes. It is for sure our biggest improvement to the code of Siril. This is why, unlike we used to do, we’ve decided to publish a beta version for the three most common platforms.
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Animation of comet Neowise

Comet NeoWise in the evening sky – above Brünstelkreuz mountain (1734m) The author: Frank Stefani is a beginner in astrophotography (since 6 months),and also been a professional photographer and experienced visual-only astronomer for over 4 decades. Bravo, I love this picture! Source:

Python to generate Siril script for cooled OSC

A big thank you to Cecile for sharing, maybe it will give you some ideas, so follow this link: Clear skies, Laurent

An article from “Libre Graphics World” talks about Siril

Take time to read this new: Week recap from “Libre Graphics World” 🙂 Follow this link:

Introduction to Siril’s GUI

Here is a video in English that presents the new interface of Siril. It will be followed by many others in order to present all the features of the Siril software. Remember to subscribe to our youtube channel.

Siril joined, the largest free/open photography community

We are proud to announce that Siril has joined PIXLS.US , the largest Free/Open Source Photography community. Like other softwares such as The Gimp, Darktable or RawTherapee we now have a forum at this address: Thank you for asking your questions on this new forum. Clear Skies, Laurent

Siril is available on flathub

Command line instructions # Install: # Make sure to follow the setup guide before installing # flatpak install flathub org.free_astro.siril Run: # flatpak run org.free_astro.siril


Siril 0.9.12 available on macOS

It is Christmas for all macOS users right now. Indeed, 0.9.12 version has been now released for this platform. You can then go to the Download section in order to get it right now.

Siril 0.9.12

We are glad and proud to announce the release of the new Siril version: 0.9.12. This version containing a lot of improvement is accessible through the download section. For more information about the new features, please follow this link .

Siril’s use in physics

Siril is not only used by amateur astrophotographers, but also by physicists from a completely different field! Source:

Siril 0.9.12 is now in RC1 version

The development of the new version of Siril continues, the version is now RC1…. This development version is available under Linux.

Siril 0.9.11 is available

We are glad and proud to announce the release of the new Siril version: 0.9.11. This version containing a lot of improvement is accessible through the download section. For more information about the new features, please follow this link .

MacOS Bundle

Hello, We are looking for a MacOS specialist who would be able to realize, or help us realize the MacOS Bundle. You can contact us at the following address: Thank you in advance for your help, The Siril development team

Get 15 % off our T-shirts and other accessories

Help us promote your favorite free astronomy image processing software by wearing Siril’s colors. Discover the T-shirt and other accessories shop for the United states / Canada, other countries.

M42 by Exaxe

Stephane Gonzales (Exaxe) shot M42 in deepksy lucky imaging. The result is so stunning that we want to share you the result. Take a seat, make your comfortable and enjoy. The English thread is on the Cloudy Night forum . To watch the full resolution follow the link .

One of the features of the next version of Siril : photometric color calibration

Siril 0.9.10

Siril 0.9.10 has been released and brings its load of new features and improvements. It provides a new comet registration method, astrometry solving, previewing for processing functions, and new commands available for scripts. Windows support has been improved, in particular for special characters in file names. We also have moved to a gitlab source and issue control system to facilitate interaction with users and developers. See other news in the release notes(https://free-astro.
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SiriL has moved to Gitlab

SiriL has moved to a new collaborative programming infrastructure hosted by Gitlab . The new URL is: On the end-user side, we also replaced our old bug submission form by the one from Gitlab.

Sirilic and Sirilot: Two very useful utilities for Siril

SIRILIC # (Siril Image Converter) is a software for preparing acquisition files (raw, Offset, Flat and Dark) for processing with SiriL software. It does three things: Structuring the SiriL working directory into sub-folders Convert Raw, Offset, Dark or Flat files into SiriL sequence Automatically generate the SiriL script according to the files present and the options SIRILOT # The Sirilic version V0.36 provides an additional tool: Sirilot It’s the contraction of “SiriL + Lot”.
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New OS X installer available

A new OS X installer, packaged by a Siril user, is now available for the 0.9.9 version. The great news of this package is that the set of DSLR scripts is now embeded as it was already done for the Windows version. Moreover, it is now possible for the user to uninstall the application very easily and properly from his computer. Go to the download section in order to get it.
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Over 500 users for Siril’s online courses

You are now over 500 to use online courses. 😉

We are looking for volunteer translators

In order to offer you the best, we are looking for volunteer translators. For the software: # No programming experience is required. See the translation instructions page for software translation. In any case, check the status of your language translation with cyril (at if you want to help. For the documentation and for the online courses: # Send an email to the following address : contact(at Many thanks in advance for your assistance.
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Starts SIRIL pre-processing from KSTARS / INDI / EKOS

You may want to use Siril scripts to automatically pre-process your images at the end of the nightly sequence with KSTARS / INDI / EKOS. Or, you also may want to download the pre-processed, registered and stacked file and not all the RAW files in the case of a remote control observatory ? Below is described the detailed procedure that was established after an exchange with Jasem, the main developer of EKOS :
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The new version 0.9.40 of CCDciel includes scripts for Siril.

It is possible to use scripts to pre-process the new images automatically for example at the end of the nightly sequence. You can now have your pre-processed files ready and immediately start the interesting part of the process. 😉 There is standard script you can use directly or if you have very specific needs you can modify them to make your own. See here:

400 users of online courses

This morning you are 400 to use this free service: Nearly 3 new users every day and this in a constant way since the opening of the service in January. A big thank you to all

What’s new in Siril 0.9.9

This release contains some new features as well as some bug fixes: # Major update of the command line, with completion and documentation in the GUI, enhanced scripting capability by running commands from a file and also allowing it to be run with no X11 server running with the -s command line option Added commands to stack and register a sequence Image statistics, including auto-stretch parameters and stacking normalization, are now cached in the seq file for better performance Global star registration now runs in parallel Workflow improvement by adding demosaicing as last part of the preprocessing Added a filtering method for stacking based on star roundness Added an option to normalize stacked images to 16-bit with average rejection algorithm All GUI save functions are now done in another thread Improved histogram transformation GUI Improved support of various FITS pixel formats Preserve known FITS keywords in the stacked image by average method Added native open and save dialogues for Windows users Various Windows bug fixes in SER handling Fixed wrong handling of scale variations in Drizzle case Fixed 8-bit images auto-stretch display Fixed BMP support Fixed issues in PNG and TIFF 8-bit export Fixed the “About” OS X menu

SIRIL 0.9.9

This release is the ninth stability release for the 0.9 branch. Its SVN revision is 2403. It also has an SVN tag: 0.9.9. Stability updates and minor improvements occur in the dedicated 0.9 branch. This is the second version officially supported on Windows, and it even includes developments that were specially made for Windows. But please keep in mind that Siril is developed without Windows and that we rely on Windows users to test and give us feedback about integration or porting problems.
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June 7, 2018 The new 0.9.9 version has been released, with bug fixes, and new script feature. February 19, 2018 A patch of the 0.9.8 version has been released: January 31, 2018 The new 0.9.8 version has been released, with bug fixes, improvements on lucky imaging and Windows integration. December 4, 2017 A new 0.9.8 version is progressing well and will particularly help people working on deep-sky lucky imaging.
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