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.
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