KStars 3.8.3 Released

KStars v3.8.3 is released on 2026.06.01 for Windows, Linux, and MacOS.

For Linux users, it's highly recommended to use the official KStars Flatpak hosted at Flathub.

This release brings major improvements to the Mount Modeler with artificial horizon filtering and uniform point distribution, significant connection speed optimizations, better guide streaming integration, and enhanced rotator handling. We've also fixed several scheduler and stability issues reported by the community. Here are the highlights:

Alignment & Mount Modeler

• Christian Kemper added Artificial Horizon filtering to the Mount Modeler wizard, allowing generated alignment points below the active horizon to be automatically filtered out. Candidate coordinate points (both generated AltAz coordinates and snapped catalog objects) are now checked and rejected if they fall into active artificial horizon regions.
• New Uniform Distribution mode generates points spread evenly across the visible sky using a Halton sequence, sampling in AltAz space to guarantee every point is above the configured minimum altitude. Points whose declination exceeds +/-80 degrees after conversion are rejected. The Any Stars, Named Stars, and Any Object modes now adopt this distribution internally and snap each generated position to the nearest qualifying object.
• Auto-sorted wizard output: points added by the wizard are automatically sorted in nearest-neighbour slew order, minimizing total slew distance. Users no longer need to click Sort after running the wizard. Clicking Sort during a run reorders only the remaining unvisited points, leaving completed rows undisturbed.
• The wizard now automatically configures the solver for each alignment point. Blind solves are used by default because no pointing model exists yet at the start of a run, so the mount's reported position may be significantly off. The GOTO mode is forced to Sync so the mount is updated after each successful solve. The original settings are saved and restored when the run finishes, is aborted, or is reset.
• Refactored point generation logic to eliminate duplicated generation and conversion math in the test suite, improving generator efficiency using a stateful sequence
• Toni Schriber fixed activation of the rotator button in the align module
• Fixed effective focal length calculation to use radians in the DSLR branch

Guide

• Thanks to Andreas Ruthner, guide streaming now correctly handles video stream window interaction. The video window no longer pops up when guide streaming starts, displays frames correctly when opened from the Capture module after a guide session, and now renders 16-bit mono stream frames (previously only 8-bit mono and RGB were handled).
• Andreas also fixed frame, binning, gain and exposure sync for streaming mode. When starting guide streaming, the module now applies the same frame settings that captureOneFrame() applies for single-frame captures. Previously, streaming mode skipped this setup entirely, causing stale values from other modules to remain active in the driver.
• Frame ROI and binning now sync on stream start, live gain updates apply immediately when the user changes the spinner during active streaming, and binning/exposure changes automatically stop and restart the stream
• Added 0.001-0.01s exposure values to the guide exposure spinner for fast streaming and daytime testing

Rotator

• Fixed several issues with Reversed rotator state not taken into account in various rotator operations
• Rotation now aborts if the Position Angle error keeps increasing due perhaps to reversed rotator behavior

Ekos Profiles & Connection

• Significantly cut down time to connect to INDI web manager by skipping DNS resolution if we already have an IP address specified for the remote host
• Fixed rare crash due to dangling clientManager pointer with test to verify the fix

Capture & Livestacking

• Use OpenCV debayering by default. Enforce even ROI selection to ensure bayer boundaries are respected.
• Always sync from INDI to overwrite shadow states in the Camera process
• Account for STREAM_FULL_DEPTH when streaming
• John Evans added support for Live Stacker Alt/AZ data via Seestar S30 Pro. It should support other telescopes in Alt/AZ mode.
• John added a gradient removal option to post processing in Live Stacker.

FITS Viewer & File Handling

• Use standard gzip compress instead of Qt own compression algorithm
• Support loading .fits.gz and .xisf.gz in the viewer

Scheduler & Observatory Automation

• Fixed scheduler freezes when loading ESL referencing many ESQ files (patch by Tomas). BUGS:519294
• Autopark should work over multiple nights now
• If observatory is not started, skip shutdown procedure
• Fixed issue where post-shutdown script run in infinite loop
• Fixed scheduler and capture scripts not running inside flatpak

Optical Trains & DBus API

• Added DBus call to set and get Pictures directory
• Fixed warning of missing devices when we already selected alternative devices in the optical train

Build & Infrastructure

• Use KSUtil to consolidate all calls to external executable so they can run correctly within a flatpak as well
• Within flatpak, run the external scripts on the host system since it may require libraries that are only available on the host system
• Christian Kemper fixed macOS iconutil failure by adding 256px and 512px icon sizes rendered from the existing SVG source, which are required by iconutil on macOS 15 (Sequoia)
• Wolfgang Reissenberger updated the Dockerfile to be based on installation scripts for all steps: INDI, StellarSolver, PHD2, GSC, openCV. All scripts are built uniformly such that existing packages or installations are preferred. If the package is missing, first installing the appropriate package is tried. If this fails, the package is built from sources

Stability & Bug Fixes

• Fixed crash reported in crash-reports.kde.org regarding invalid base device or message text. The check for message text now occurs earlier in the process to protect against this crash.
• Milhan Kim fixed test deadlock by replacing QTest::mouseClick with animateClick(), which posts the click through the event loop and prevents tests from hanging indefinitely on QDialog::exec() loops
• Fixed an issue where frequent temperature updates can cause the dark cover check to run indefinitely
• Hy Murveit fixed green lines display issue
• Fixed solution assignment
• Fixed crash and distorted artifacts in video streaming
• Replaced all abs and fabs with std::abs for consistency
• Modernized signals and slots

Many thanks to Christian Kemper, Andreas Ruthner, Toni Schriber, Hy Murveit, John Evans, Milhan Kim, Wolfgang Reissenberger, Tomas, and all others who contributed fixes and improvements to this release! Your work makes KStars better for everyone.

Download KStars v3.8.3 today and enjoy improved mount modeling, faster connections, and more reliable guiding!

KStars 3.8.2 Released

KStars v3.8.2 is released on 2026.04.08 for Windows, Linux, and MacOS.

For Linux users, it's highly recommended to use the official KStars Flatpak hosted at Flathub.

This release brings reliability improvements across the scheduler, live stacking, polar alignment, along with new features like passive camera warming, a startup queue failure popup, and preliminary automatic polar alignment correction. Here are some highlights:

 Scheduler & Observatory Automation

• Fixed Ekos not shutting down after preemptive shutdown; task executor no longer stalls when a park command is issued
• New startup queue failure popup with state reset for clean retries
• Scheduler restart from error state now always resets startup to IDLE
• Fixed crashes caused by improper use of QSharedPointer; simulator-based regression tests expanded
• Added ability to wait indefinitely for weather to improve
• Profiles now synced from INDI Web Manager on startup; deleting a profile in KStars removes it from the manager
• Fixed checkINDIState returning incorrect value when transitioning to STARTUP_POST_DEVICES
• Added Optical Trains DBus interface for scripted access to train configuration

Polar Alignment

• Preliminary support for Automatic Polar Alignment Correction via the INDI Polar Alignment Corrector interface. INDI Polar Alignment Drivers include Avalon UPAS (not tested) and MLAstro Robotic Polar Alignment (not released yet)
• Fixed overwrap calculation error producing erroneous correction vectors
• Multisetup PA sync workaround contributed by Philip Mair

Live Stacking

• Added mutex locking on LiveStack image buffer updates to prevent SEGVs under concurrent load (John Evans)
• Livestacker settings are now retained between sessions; parameters synced programmatically to UI
• Fixed saved .xisf stacks to store pixel values in the correct 0→1.0 range
• Stacker now restarts automatically when the filter or imaging target changes

Capture & Focus

• Added passive camera warming for graceful end-of-session cooldown
• Fixed critical bug where autofocus triggered by a filter change could leave sequences stuck indefinitely
• Fixed sequence filter not being restored after a meridian flip when autofocus is not required (Pavan Kumar S G)
• Fixed dithering getting stuck in streaming mode
• Fixed crashes when closing compressed FITS files and failure to open compressed FITS images (Umangjeet Singh Pahwa)

Guiding

• Initial work to support streaming mode in the guide module, enabling video-capable cameras for guiding. This is especially useful for harmonic mounts where you can guide at higher frequency (2-4 Hz)

Other Fixes

• Added dome slit overlay to the sky map view (Ed Lee)
• Various dust cap and light box device handling improvements
• Fixed INDI Web Manager port detection on macOS and Windows
• Suppressed spurious empty disconnect messages on clean disconnects
• Mount unpark no longer passes a hardcoded "Mount" string; INDI resolves the device by interface type

KStars 3.8.1 is Released

KStars v3.8.1 is released on 2026.02.092 for Windows, Linux, and MacOS.

For Linux users, it's highly recommended to use the official KStars Flatpak hosted at Flathub. You can install the stable flatpak or try out new features by downloading the KStars Nightly Flatpak for x86_64 and arm64 architectures.

This is mostly a bugfix release with nice improvements in debayering algorithms thanks to John Evan's work on this using OpenCV. Here are some highlights:

 Scheduler & Observatory Automation

• Enhanced weather-based scheduling with proper abort/resume during soft shutdown
• Improved preemptive shutdown with wakeup timers and better state management
• Safety monitor now continues monitoring even after complete shutdown
• Fixed jobs incorrectly marked as aborted when completed

Live Stacking Improvements

• Added debayering support for multiple cameras including Touptek
• Implemented hot/cold pixel removal
• Added XISF file format support with debayering
• General bayer processing refactoring
  
  
  
  
  

Meridian Flip & Alignment

• Fixed capture operation timeouts during meridian flips
• Added extensive logging for post-flip actions
• Improved rotator timeout handling - now aborts alignment instead of waiting indefinitely

Reliability & Error Handling

• More resilient INDI web manager connectivity checks with graceful failures
• Fixed ADU-based flat frame signature matching
• Improved filter offset handling for multi-camera setups
• Better dark frame diagnostic logging

Other Fixes

• Fixed comet position calculations for hyperbolic orbits (e.g., 3I/ATLAS)
• Improved artificial horizon importer to handle spaces in files
• Enhanced HIPS survey filtering and sorting with partial sky survey support. Support for many more catalogs like NSNS
  
  
  
  
  
  

KStars v3.8.0 is Released

KStars v3.8.0 is released on 2025.12.03 for Windows & Linux. MacOS release is expected in one week due to build issue on KDE CI infrastructure.

For Linux users, it's highly recommended to use the official KStars Flatpak hosted at Flathub. You can install the stable flatpak or try out new features by downloading the KStars Nightly Flatpak for x86_64 and arm64 architectures.

Live Stacker: LRGB Stacking

John Evans implemented generation of RGB and LRGB images from individual mono subframes. Watch R, G, B and optionally L directories and combine the individual stacks into RGB or LRGB images.

Add directories for R, G, B and optionally L subs. These are monitored and a single color image is displayed.

RGB images are combined with a Linear Fit type algorithm.  LRGB images are combined with a LRGB Combination type algorithm. SNR algorithm has been rewritten. Appears to work better but is more resource intensive.

Live Stacker: ImageMM Stacking Method

John Evans added an implementation of the ImageMM stacking method. This implementation strikes a balance between speed (it needs to be a Live Stacker) and fidelity.

To use: select ImageMM as the stacking method and play with the available controls. This method is considerably more resource intensive than "regular" stacking because it uses an iterative approach.

Live Stacker: Live Stacker Monitor

John Evans implemented the Live Stacker monitor. Live Stacking Monitor window is a popup from Live Stacker that shows a table of subs that match the chosen directory in Live Stacker.

The purpose is to allow analysis of Live Stacker, for example to allow investigation of bottlenecks in the stacking process.

When a sub is added to the watched directory, the sub is added to the Monitor's table. As the sub is processed by each step of the process information is updated in the table:

• Waiting to load. The sub is in the queue to be processed but Live Stacker is busy with other subs.
• Loading. The sub is loaded into memory.
• Plate solving. The sub is undergoing plate solving (if appropriate).
• Waiting to stack. The sub is waiting to be stacked (e.g. currently there are insufficient subs loaded to start a stack).
• Calibration. Dark / Flat calibration.
• Alignment.
• Stacking.

Table columns and sort order are configurable. Changing cells can be highlighted (or not)

Task Queue system

Observatory startup and shutdown steps are now replaced by the new highly configurable Task Queue system. The Task Queue System is a modern, flexible automation framework that replaces traditional startup and shutdown scripts with a template-based, configurable task execution system. It provides a visual interface for building sequences of automated operations that can control your observatory equipment through INDI. It is accessible from Ekos Scheduler.

Why use it? The Task Queue system offers several advantages over traditional scripting:

• Visual Management: Build and monitor task sequences through an intuitive graphical interface
• Reusability: Use pre-built templates for common operations without writing code
• Error Handling: Built-in retry logic and configurable failure responses
• Device Compatibility: Automatic matching of templates to available devices
• Progress Monitoring: Real-time status updates and detailed execution logs
• Collections: Pre-defined task sets for startup, shutdown, and other common scenarios
• Flexibility: Combine templates or create custom variations without programming

Safety Monitor

KStars scheduler now fully supports INDI Safety Monitor driver released part of INDI v2.1.7. A standalone driver may be used (independent of the equipment profile) that is running on a different INDI server to provide 24/7 safety monitor updates to the scheduler. No observatory operations shall take place unless it is deemed safe by the safety monitor.

The INDI Safety Monitor can listen to any number of sources including weather stations, UPS (uninterruptible power supply) monitors, and any auxiliary device that support the INDI's standard SAFETY_STATUS property.

Push-To Assistant 

Wolfgang Reissenberger added an incredibly useful tool for users with manual mounts: Push-To Assistant. Just attached a camera to your dobsonian and use this tool to center the target in the eyepiece. This tool assumes that both the camera center and eyepiece center are already aligned.

The new push-to assistant is intended as plate solving support for mechanical mounts in combination with a digital camera on a finder scope.

Setup: Create an optical train with the Telescope Simulator as mount and configure your combination of finder scope and digital camera.

Usage

• Start Ekos
• open the Push-to Assistant located in the Tools menu
• move your scope as good as possible to the target you want to find
• select the target from the catalog or enter its coordinates manually and press "Select target"
• press "Solve position" to determine the position your scope is currently pointing at
• as soon as the position has been solved, the assistant displays hints in which direction you should move your mount to be closer to the target
• correct your mount position and press "Solve position" again

if you want to automatically repeat plate solving, configure the delay and press the "Repeat" button.

Bug Fixes

• Fix crash when connecting to remote host because the clientManager was not set.
• When restarting capture, update job captured frame map from module state.
• Fix issue with J2000 getting set by default in Mount Control Panel.
• Fix regression where capture format and encoding are reset whenever they are changed in INDI.
• Use the offline HIPS path since it can be a custom location
• Prevent premature alignment run if there are no more light frames in the job
• Do not cover dust cap when capturing sky flats.
• Fix setFrame when loaded from XML as DARK was incorrectly decoded as BIAS frame.
• Remove parents from constructors of objects pointed to by QSharedPointer
• Fix issue in FITS Solver, need to disconnect signals in callbacks
• Fix bug in one-pulse-dither, update logging
• Fix issue in analyze stats font size
• Placeholder %cam removed
  
  

KStars v3.7.8 is Released

KStars v3.7.8 is released on 2025.08.13 for Windows & Linux. MacOS release is pending. It's a bi-monthly bug-fix release with a couple of exciting features.

Live Stacking

The moment many of you have been waiting for has arrived! John Evans has introduced the highly anticipated Live Stacking feature to Ekos, seamlessly integrated into the FITS Viewer. Once you configure your live stacking directory, any FITS images added will be automatically stacked in real-time.

This feature works independently of your existing sequences or scheduler sessions, allowing you to configure the live stacker to process captured images for an enhanced view of your final results. It's particularly valuable for public observatories and star parties, where real-time feedback can greatly enhance the viewing experience.

Since Live Stacking is still in beta, we welcome your feedback and suggestions for improvement. Check out the demonstration videos below to see the feature in action and learn about its capabilities.

Equipment Profile Editor

The Ekos Equipment Profile editor has received a complete redesign. We've eliminated the limitations of the previous editor—you can now add unlimited drivers to your equipment profiles without restrictions. Need three different mounts in a single profile? No problem!

Both driver and profile lists now include search functionality, making it quick and easy to locate specific drivers. This flexibility gives you unprecedented control over your equipment configurations.

Focus History Navigation

Wolfgang Reissenberger has added an invaluable Focus History navigation feature. When autofocus encounters issues, you can now navigate through your focus frame history to inspect images from all autofocus runs, making troubleshooting much more effective.

The Focus module now includes a dedicated navigation panel. To optimize screen real estate, we've moved the detected stars display and current HFR readings above the V-Curve rather than below it, freeing up valuable space.

To use this feature, simply configure the maximum number of stored frames in your Focus settings. The navigation controls are active only when autofocus sequences aren't running.

FITS Viewer Stretch Presets

Hy Murveit has refined the FITS Viewer stretch sliders and added a convenient preset button that cycles through seven different stretch configurations, offering various combinations of background brightness and contrast levels.

When you display the histogram and zoom in, the sliders provide much finer resolution control—particularly useful for precise black point adjustments.

Flatpak Support

Thanks to extensive collaboration between the Ikarus Technologies team, KDE Infrastructure team, and the Flathub community, we now offer both Stable and Nightly Flatpak packages.

The KStars Flatpak includes all INDI drivers and runs securely within the flatpak sandbox environment. This allows you to install both Stable and Nightly versions simultaneously without conflicts; perfect for testing the latest features and bug fixes while maintaining access to the stable release.

For installation on a brand new system, you'll need to install INDI firmware files. We've prepared comprehensive instructions and a simple installation script for both stable and nightly versions to facilitate this process.

Polar Alignment Improvements

Hy Murveit improved the Polar Alignment algorithm, especially when it the mount is close to the meridian. Wolfgang Reissenberger improved the the size of the arrows indicating the direction of the necessary adjustments so they're more visible in the Polar Alignment Assistant.

Migration to Qt6

This release represents a significant technical milestone with our complete migration to Qt 6 and KDE Frameworks 6. KStars is still compatible with Qt 5 until all major distributions fully switch to Qt 6. While these changes happen behind the scenes, they provide a more robust foundation for future development.

The entire KStars development team contributed to this substantial effort. Special recognition goes to Eric Dejouhanet and Robert Lancaster, who invested countless hours reworking our complex CI/CD pipelines and macOS support builds in KDE's Craft system. This release wouldn't have been possible without their exceptional dedication.

KStars v3.7.6 is Released

KStars v3.7.6 is released on 2025.04.01 for Windows, MacOS & Linux. It's a bi-monthly bug-fix release with a couple of exciting features.

Scheduler Plans Visualized

Hy Murveit added a graph to the Scheduler page that displays visually the scheduler's plans--the same plans described in the log at the bottom of that page, and partially described in the scheduler's table. You can see altitude graphs for all the scheduler jobs, which are highlighted in green when that job is planned to be active. The next two nights of the plan can be accessed using buttons to the right (and left) of the graph. The graph can be enlarged or hidden by sliding the "splitter" handle above it up or down.

PHD2 & Internal Guider RMS

Many users reported differences between the RMS value reported by Ekos internal guider vs PHD2. This is not a new issue as there was a difference in RMS calculations ever since Ekos Guider module was developed over a decade ago. In this release, we updated the internal Guider RMS calculations to use the same algorithm used by PHD2. This way, there is now a more consistent metric to judge the performance of the two guider systems.

Weather Scheduler Integration

Weather station integration with the scheduler was improved. The weather enforcement is now global and not per job. If weather enforcement is enabled, you can adjust the Grace Period (default 10 minutes) in cases where the scheduler cannot be started due to a weather Alert or Warning. 

When a weather warning is received, existing jobs can continue to execute but new jobs will not be executed until the weather situation improves. Upon detecting a weather hazard, the scheduler execute a Soft shutdown mode where it can park the mount and dome, but still retains connection with INDI drivers to continue monitoring the weather situation. If the weather does not improve by the Grace Period, it then commences a full shutdown of the observatory. Otherwise, it should resume the job from where it was left.

Contrast Based Focusing

John Evans added an option to allow focusing on non-star fields by using various contrast based algorithms. This is suitable for Lunar, Solar and planetary imaging.

Autofocus Optimization

John Evans added an option has been added to Focus that allows an Autofocus run to re-use a previous successful Autofocus result if the previous AF run occurred within a user-defined time period, say <10mins ago. This can speed up certain situations when using the Scheduler where multiple Autofocus requests can happen within a short period of time.

Imaging Planner Improvements

Hy Murveit pushed a new Imaging Planner catalog release along with improvements to the KStars Imaging Planner.

• It should now start up much more quickly on first use, or first use after a catalog upgrade.
  
• There were stability improvements.
  
• The catalog was extended to include 770 objects.
  

Upgrade to KStars 3.7.6, use Data -> Download New Data to get the latest Imaging Planner catalog, and run Load Catalog in the Imaging Planner tool to take advantage of all these improvements.

Quick Go & Rotate

Added support to Go and Rotate in Framing Assistant. This would command fast go to target and then followed by rotation to match position angle indicated. Simply adjust the Position Angle to your desired angle then command Ekos to solve and rotate in one go.

Scheduler Coordinates Flexibility

Wolfgang Reissenberger introduced enhancements for handling target coordinates in the scheduler module:

• Add an option to switch the target coordinates between J2000 and JNow. This is interesting for those cases where the user wants to enter the coordinates manually, but has the coordinates only in JNow - for example when taking them over from the align module.
• Add a "use the current target" button. Currently, there is only an option to take over the current skymap center.

Furthermore, during the time where the moon is visible, it should be possible to schedule only those jobs that are not disturbed by moonlight (e.g. H-alpha captures). To enable this, a new optional constraint is introduced where the maximal moon altitude could be set.

Use PHD2-scheme graph

Toni Schriber modified the internal guider chart to use PHD2-scheme (RA/DEC) for graph of guide mount drift. This should help comparisons between PHD2 and internal guider more consistent.

KStars v3.7.5 is Released

KStars v3.7.5 is released on 2025.02.03 for Windows, MacOS & Linux. It's a bi-monthly bug-fix release with a couple of exciting features. Here are the release notes organized by developer.

Jasem Mutlaq

• Added dome slit visualization on sky map. Specify the Dome Measurement parameters in the INDI Dome driver to see a live dome slit overlay in the Sky Map.

• Implemented generic DBus methods for KStars options
• Added SchedulerSleeping event
• Added mutex protection for multi-threaded resources
• Enhanced scheduler loading and settings management
• Improved filter manager operations
• Fixed video subframing. Up to 50x improvement in subframed video feeds.
• Fixed multiple profile editor issues
• Added VSCode development setup support

Hy Murveit

• Fixed DMS delta angle calculation
• Added mandatory settle to PAA
• Improved imaging planner stability

• Fixed pierside placeholder directory usage
• Added START_AT scheduler test
• Fixed Abell planetary nebula lookup
• Enhanced PAA adjustment estimation

Wolfgang Reissenberger

• Implemented video sequence capture. Preliminary support for capturing Video files as regular sequences in the Capture module. Great news for EAA.

• Fixed focus options
• Improved remote directory handling
• Fixed flats with wall position
• Enhanced filter wheel integration

John Evans

• Enabled focuser controls when camera disconnected
• Improved focus measure framing
• Fixed focus advisor code warnings
• Updated aberration inspector functionality

Toni Schriber

• Fixed overshooting cosine in CachingDms calculation
• Implemented calibration reuse after rotation. Guide calibration data can now be re-used between sessions after rotation.

Ben Cooksley

• Removed CMake trace/debug logs from CI runs

György Balló

• Set window icon

Oliver Kellogg

• Fixed typo in FITS Viewer configuration

Akarsh Simha

• Fixed right-click popup menu on deep stars

Technical Highlights

• Improved capture sequence stability: Set 5-minute timeout for transient operations (dome motion, mount parking/unparking, dust cap operations, focusing, filter wheel changes) to prevent indefinite sequence stalling.
• Improved mount rotation processing
• Enhanced scheduler loading mechanism
• Added mutex protection for multi-threaded resources
• Improved capture operation timeout handling