Software Index

This page organizes the software commonly used in astronomical observation and astrophotography by stage in the workflow. Each tool is given a one-line purpose, the platforms it runs on, and the nature of its price (free / paid / partly paid). For the complete processing pipeline, see the post-processing workflow; if you use hosted equipment, the various remote platforms already bundle most of this capture and control software, see remote platform comparison.

Pricing and platform information changes as versions are updated; the tables below reflect the situation at the time of writing (2026). Always check the official website before purchasing or downloading.

One free beginner pipeline

You don’t need to install all of this software when starting out. One complete, entirely free pipeline is: Stellarium (choose targets, check visibility) → N.I.N.A. + PHD2 (automated capture and guiding) → Siril (calibration and stacking) → GraXpert + StarNet++ (gradient removal and star removal for post-processing). Once familiar with the workflow, bring in professional / paid tools such as PixInsight or BlurXTerminator as needed.

Software categories and their place in the workflow

Astrophotography software can be divided into five categories by its position in the workflow. There is overlap between them: some software (such as Siril and PixInsight) covers both stacking and post-processing, and some handheld devices (such as ASIAIR) integrate planning, capture, and guiding into the hardware.

Stage	Main task	Representative software
Planning and star charts	Choose targets, check visibility, assess light pollution and weather	Stellarium, SkySafari, Telescopius, Clear Outside
Capture control and guiding	Control camera / mount, automated sequences, guiding	N.I.N.A., ASIAIR, SharpCap, PHD2, FireCapture
Stacking (preprocessing)	Calibrate, align, and stack sub-frames to improve signal-to-noise ratio	DeepSkyStacker, Siril, AutoStakkert!, PixInsight
Post-processing	Stretch, gradient removal, noise reduction, star removal, sharpening, color grading	PixInsight, Photoshop, GraXpert, StarNet++
Community and databases	Image hosting, parameter lookup, target search	AstroBin, Telescopius

Planning and star charts

Used before observing or imaging to select targets, simulate framing, look up the visibility of celestial objects, and assess light pollution and weather windows. This stage works together with observation planning; the visibility assessment here can be understood alongside hemisphere visibility and celestial coordinates.

Name	Purpose	Platform	Price
Stellarium	Open-source desktop virtual planetarium; simulates the sky, star charts, and framing for any time and location, and can control GoTo mounts	Win / Mac / Linux	Free (GPLv2)
Stellarium Mobile	Mobile star chart; a subset of the desktop version’s features	iOS / Android	Free / paid (Plus edition)
SkySafari	Phone / tablet star chart; supports telescope GoTo control and real-time tracking	iOS / Android / Mac	Free / paid (by edition)
Cartes du Ciel (SkyChart)	Open-source star chart; supports a large number of catalogs such as Gaia and UCAC, and can control mounts via ASCOM / INDI	Win / Mac / Linux	Free (GPLv2)
Telescopius	Online deep-sky target library and framing tool (Telescope Simulator); filters by size, altitude, lunar distance, and other criteria and generates target lists	Web / iOS / Android	Free / paid (advanced)
Light Pollution Map	Online light pollution map; overlays SQM and VIIRS data to look up the Bortle scale	Web	Free
Clear Outside	Hour-by-hour weather forecast designed for astronomical observation; provides cloud cover (low / medium / high / total), moon phase, and sun and moon rise, set, and transit times	Web / iOS / Android	Free

Shared capabilities of star chart software

Desktop star charts (Stellarium, Cartes du Ciel) and mobile star charts (SkySafari) overlap heavily in features: all can render the sky by time and location, show the positions of planets and deep-sky objects, and slew a GoTo mount via ASCOM / INDI / vendor protocols. The differences are mainly in interaction (keyboard and mouse vs. touchscreen), catalog size, and offline availability. Pick one you’re comfortable with—there’s no need to learn several at once.

Capture control and guiding

Controls the camera, filter wheel, motorized focuser, and mount to run automated capture sequences; guiding software, meanwhile, monitors a reference star in real time to compensate for the mount’s periodic error and polar alignment error, thereby extending the exposure time per frame. Deep sky (long exposures, few frames) and planetary / lunar / solar imaging (short exposures, high-frame-rate video) place markedly different demands on software.

Name	Purpose	Platform	Price
N.I.N.A. (Nighttime Imaging ‘N’ Astronomy)	Fully automated deep-sky capture: sequence orchestration, autofocus, meridian flip, plate solving, framing assistant	Win	Free (open source)
ASIAIR	All-in-one handheld control box in the ZWO ecosystem (built-in Raspberry Pi); the app controls the camera, mount, guiding, polar alignment, and plate solving	iOS / Android (includes hardware)	Paid (with hardware)
SharpCap	Live view, electronically assisted astronomy (EAA) live stacking, planetary capture, sensor-based polar alignment	Win	Free / paid (Pro)
APT (Astro Photography Tool)	Capture automation suite for DSLR / astronomy cameras; works with PHD2 to perform dithering	Win	Paid (inexpensive single license)
PHD2 Guiding	Open-source autoguiding (Push Here Dummy); compensates for tracking error to extend exposures, supports dithering	Win / Mac / Linux	Free (open source)
FireCapture	High-frame-rate video capture for planetary / lunar / solar imaging; broadly compatible with ZWO, QHY, Altair, and other cameras	Win / Mac / Linux	Free

Platform and ecosystem lock-in

Capture control software is often tied to a hardware ecosystem. N.I.N.A. supports most brands of equipment via ASCOM drivers but runs only on Windows; ASIAIR is convenient to operate but is essentially only compatible with ZWO’s own cameras and supported mounts. Before choosing, confirm whether the software supports your camera, filter wheel, and mount interface (ASCOM / INDI / vendor-proprietary protocol) to avoid ending up with a combination that can’t work together.

Stacking (preprocessing)

Aligns and stacks tens to hundreds of sub-frames after calibration (dark, flat, bias) to improve the signal-to-noise ratio (SNR)—stacking N frames theoretically reduces random noise by about a factor of sqrt(N); for the principle, see signal-to-noise ratio. Deep sky uses long-exposure multi-frame stacking, while planetary / lunar imaging extracts and stacks the highest-quality frames from high-frame-rate video—that is, lucky imaging.

Name	Purpose	Platform	Price
DeepSkyStacker (DSS)	Entry-level deep-sky stacking tool; the workflow is intuitive and well suited to single-session datasets	Win	Free
Siril	Open-source deep-sky calibration + stacking + basic post-processing; supports script automation and mosaic stitching	Win / Mac / Linux	Free (open source)
AstroPixelProcessor (APP)	All-in-one tool from calibration to finished image; excels at mosaic stitching and background / gradient correction	Win / Mac / Linux	Paid (subscription or one-time purchase)
AutoStakkert! (AS!3)	Planetary / lunar video frame extraction and multi-point alignment stacking (lucky imaging); the mainstream choice for planetary imaging	Win	Free
PixInsight WBPP	PixInsight’s built-in batch script (WeightedBatchPreprocessing); automatically performs calibration, registration, and weighted stacking	Win / Mac / Linux	Paid (with PixInsight)

Stacking quality depends on parameters, not the software

PixInsight, Siril, and APP have no absolute hierarchy in stacking quality; PixInsight’s advantage lies in its very large number of adjustable parameters, allowing experienced users to fine-tune for their data. A common approach is to use Siril or DSS to quickly obtain a stacked result, then move to PixInsight, APP, or Photoshop for post-processing. When starting out, prefer the simpler workflow of DSS or Siril.

Post-processing

Processing after stacking: nonlinear stretch, removal of background gradients / light pollution gradients, noise reduction, star removal (to process the nebula separately), sharpening, and color balance. The post-processing path differs for deep sky and planetary imaging—deep sky focuses on gradients and noise reduction, while planetary focuses on wavelet and deconvolution sharpening.

Name	Purpose	Platform / host	Price
PixInsight	Professional astronomical image-processing platform; covers the full pipeline from calibration and stacking to deep-sky post-processing, with rich adjustable parameters	Win / Mac / Linux	Paid (one-time purchase)
Photoshop	General-purpose image editor; often used for the final touch-up and layer compositing of deep-sky images	Win / Mac	Paid (subscription)
GraXpert	AI gradient / light pollution gradient removal, plus AI noise reduction; runs standalone or as a plugin	Win / Mac / Linux	Free
StarNet++	AI star removal / star extraction, making it easier to process nebula detail separately; often used as a PixInsight plugin	Win / Mac / Linux	Free
StarXTerminator	AI star removal with better preservation of nebula structure	PixInsight / Photoshop / Affinity	Paid
BlurXTerminator	Deconvolution based on a deep neural network; sharpens stars and detail and corrects aberrations	PixInsight plugin only	Paid
RegiStax	Classic wavelet sharpening tool for planetary / lunar imaging (now essentially discontinued)	Win	Free
AstroSurface	All-in-one processing for planetary / lunar / solar imaging; integrates the PIPP + AutoStakkert + RegiStax workflow, with wavelets and RL deconvolution	Win	Free

Host requirements of paid plugins and common misconceptions

The X-Terminator series from RC Astro has different host requirements: BlurXTerminator can only run as a PixInsight process module; StarXTerminator and NoiseXTerminator support both PixInsight and Photoshop (the Photoshop version can also be used in Affinity Photo). Before buying, confirm that you already have the corresponding host software.

A common misconception: deconvolution sharpening (BlurXTerminator) and star removal (StarXTerminator) are two different operations and must not be confused; AI tools can improve results but cannot make up for raw data with insufficient exposure or poor tracking—the signal-to-noise ratio is still determined at the capture stage, see signal-to-noise ratio.

Community and databases

Used to host finished images, look up others’ capture parameters, and search for deep-sky targets. AstroBin is both an image community and, in effect, a database of equipment and capture parameters; Telescopius combines target search and framing functions (already listed under “Planning and star charts”).

Name	Purpose	Platform	Price
AstroBin	Astrophotography image hosting community; can publish / view full equipment, exposure, and processing parameters, with built-in plate solving	Web	Free (limited uploads) / paid (Lite / Premium / Ultimate tiers)
Telescopius	Online deep-sky target library; supports search by catalog, coordinates, and visibility, and generates observation / framing plans	Web / iOS / Android	Free / paid (advanced)

Remote imaging doesn't require you to own all the software

If you don’t have your own equipment, many remote observatory platforms already bundle the capture, guiding, and control software above; you only need to remotely submit an imaging plan and download the raw data, then do the stacking and post-processing locally. For a comparison of each platform’s toolchain and pricing, see remote platform comparison.

Post-processing workflow String the software above into a complete pipeline from sub-frames to finished image.

References

• Stellarium — Wikipedia — The license, platforms (including Stellarium Mobile), and rendering features of the open-source star chart software.
• Cartes du Ciel — Wikipedia — Catalog support and ASCOM / INDI telescope control details for the open-source star chart.
• Astrophotography Image Stacking Software — AstroBackyard — A comparison of the purpose and platforms of stacking tools such as DeepSkyStacker, Siril, PixInsight, and APP.
• BlurXTerminator / StarXTerminator / NoiseXTerminator — RC Astro — The features and host (PixInsight / Photoshop / Affinity) requirements of the X-Terminator series of AI plugins.
• AstroBin Pricing — AstroBin’s free quota and Lite / Premium / Ultimate subscription tiers.
• Clear Outside Forecast — The source of the hour-by-hour weather, cloud cover, and moon phase forecast data oriented toward astronomical observation.