Phoranso; Photometric Reduction and Analysis Software; photometry; FITS files; astrometric solver; aperture photometry; ensemble photometry Phoranso - Photometric reduction and analysis software

Experience unmatched Photometric mastery with Phoranso

[Photometric Reduction and Analysis Software]

Phoranso streamlines your Photometric analysis process and unfolds your light curves while you're observing

Crafted by Tonny Vanmunster, author of the Peranso period analysis software, Phoranso embodies 30 years of photometric expertise. With over 2 million high-precision Exoplanet and Variable Star observations to his name, Tonny has pioneered a groundbreaking solution, elevating Phoranso to unrivaled heights as the definitive choice for Photometric Reduction and Analysis Software in the market.

We are delighted to announce the release of Phoranso 1.0


To get started with Phoranso, including access to a trial version, please visit our download page.

Phoranso is distributed as shareware.

Note that registration is required to activate Phoranso for use on your personal computer

Contact us at for more information.

Discover the Powerful Advantages of Phoranso: Unleashing Unparalleled Capabilities

Unlock the power of Multi-star photometry
Phoranso enables you to measure all variable stars present in your FITS images, seamlessly generating Photometric reports in AAVSO, CBA, CSV and Excel formats

Experience the versatility of Phoranso with support for both single-reference photometry and ensemble photometry

Auto-detects all AAVSO VSX variable stars present in your FITS image
Say goodbye to manual searching of variable stars in your images

Highlights ideal comparison, check and reference stars for your photometry
Using stellar color indices to highlight advised comparison stars in your FITS images

Live Photometry mode
Launch Phoranso at the beginning of your observing session and experience the magic as it swiftly generates photometric reports for variable stars captured in your FITS images by the session's end

Witness the captivating unfolding of your light curves in real-time during image acquisition, empowering you with instant insights

Intelligent Variable Star Database
Phoranso revolutionizes your workflow by building a comprehensive database of all your variable stars. Enter your variable star and comparison star information once, and Phoranso will memorize them for future usage. Leave behind repetitive data entry and streamline your efficiency

Integrated astrometric solver
Phoranso integrates an advanced astrometric solver that delivers exceptional accuracy and performance, using the Gaia DR3 catalogue.

Also connects with the free ASTAP solver and with the commerical PinPoint 32-bit and 64-bit solvers

Seamless end-to-end Photometric pipeline
Phoranso takes your science (raw) images, performs automatic bias-dark-flat calibration and solving, and extracts photometric information, all in one streamlined step. Say goodbye to the hassle of using multiple tools

Phoranso manages diverse FITS file formats, accomodating pixel depths up to 64-bits. Additionally, if offers support for Bayer Color FITS files, automatically converting them to grayscale images

Precision aperture photometry
Phoranso sets the bar high with its meticulous focus on photometric accuracy and user-friendly experience, establishing itself as one of the most productivity-driven photometry packages in the market. Integrates the UCAC4 and APASS DR10 photometric catalogs

Generate light curves and reports effortlessly across multiple star aperture settings (multiple ringsets) in a single, seamless operation

Robust scripting capabilities
Enabling effortless integration of Phoranso in your existing tools and workflows

Execute Phoranso commands directly from a Windows Command Prompt or through scripting languages such as Python, among others

Compatible with Lesve Photometry
Experience the convenience of importing all of your Lesve Photometry star sequences in a single step in Phoranso

Start and stop your photometric analyses at any point in time
Effortlessly resume right where you left off, without the need to reprocess images

Launch multiple photometry sessions in parallel
You can even calibrate images while one or more photometry sessions are in progress


Phoranso is ready for download

Click here to download, then follow the installation instructions. Encountering issues with downloading, installing, or running Phoranso? Refer to the Troubleshooting section in the User Guide, or feel free to reach out to us via email, and we'll gladly provide support to resolve your concerns.

We highly recommend starting your exploration of Phoranso using the tutorial and sample FITS files provided for download. These files are an integral part of the tutorial execution and will help you get started effectively. 

If you encounter any issues or have questions using Phoranso with your own FITS files, please don't hesitate to contact us. Feel free to include your FITS file as an attachment in your email. We're here to help!

Explore the Changelog section to uncover the updates and modifications included in the latest version of Phoranso.



Phoranso Registration Keys


Phoranso operates under a shareware model, offering a free 10-day trial period upon initial usage. During this trial, Phoranso is fully functional but it will generate photometric reports containing a random selection of your observations.

Should you find Phoranso beneficial during the trial, we invite you to register, removing these limitations and converting your trial version into a regular one.

System requirements

Ensure your PC or laptop meets the following minimum specifications: 4 GB of RAM, screen resolution of 1920x1080 or higher, and Microsoft Windows 10 or Windows 11 (64-bit version).

Running Phoranso in full screen mode (maximized) ensures that you make the most of your display space, offering a clutter-free environment.

Although Phoranso has been developed as a Microsoft Windows product, it runs successfully on other operating systems too, using appropriate desktop virtualization software. We advise VirtualBox from Oracle Corporation.


Phoranso and virus scanners


Some antivirus software may incorrectly flag Phoranso as infected with a virus during downloading or installation. Rest assured, we thoroughly scan Phoranso for viruses before every release to ensure it's 100% safe.

The incorrect detection of a virus in Phoranso is known as a false positive. This happens if a file contains a string of characters that matches those of a known virus, leading to the false detection.

If you encounter a false detection, you may need to unblock Phoranso to prevent its removal. Consult the documentation of your antivirus software, for unblocking or whitelisting procedures, or reach out to us. Whitelisting refers to the process of explicitly allowing certain software or files to bypass security checks.



Registration of Phoranso turns your trial version into a paid regular version, removing the limitation that your photometric reports contain a random selection only of your observations.

The registration process is simple: upon completion, you'll receive a Registration Key by email to enter once into Phoranso, granting usage for an unlimited duration.

Your Registration Key is valid for the specific computer and operating system you are using. It will not allow you to run Phoranso on any other PC. If you want to run Phoranso on more than one computer, you will have to purchase an additional Registration Key for each PC, at a discounted rate (see table below).

It's important to note that your Registration Key is valid for one year, entitling you to free software updates and technical support during this period. After expiration, while you can still use Phoranso, you won't receive updates or support unless you renew your Registration Key.

Renewal is available at any time, even after expiration, detailed instructions can be found in the User Guide. We recommend annual renewal to ensure access to the latest Phoranso updates and technical assistance.

 Phoranso - Registration Keys


US$ (approx)


 Single Registration Key
(for usage on 1 PC)




Second Registration Key
(for usage on a 2nd PC by a registered user)




Annual Registration Key renewal



Pack of 2 Registration Keys



  Pack of 3 Registration Keys




  Pack of 4 Registration Keys




  Pack of 5 Registration Keys




  Pack of 10 Registration Keys





Payment methods

  • We support several payment methods (PayPal, Visa, Mastercard, American Express) as well as some country specific methods. Click the Pay Now button in the above table to proceed to the Phoranso order page.

  • You can also wire the EUR money to our bank account:

     IBAN: BE71 0637 0541 6569


     Name:, Tonny Vanmunster, BELGIUM

* Quoted prices are VAT exclusive for business customers, and VAT inclusive for private persons. Invoice provided upon simple request




  • Improved the handling of FITS images that do not adhere to the FITS 'standard' through enhanced FITS keyword support.
  • Updated files solved by Phoranso to ensure proper handling in AstroImageJ.
  • Resolved an issue in the report generation that caused multiple instances of the same report.
  • All UCAC4 star names are now written using the correct UCAC4 nomenclature.
  • Extended the CBA report to also include the target name's variability type, magnitude range and period.





  • For a FITS image having no JD and MIDPOINT keywords, Phoranso calculates the mid exposure time using the DATE-OBS and TIME-OBS keywords. In case also the TIME-OBS keyword is missing, the calculated mid exposure time was wrong. This has now been fixed.
  • FITS images produced by ZWO ASIImg are lacking the IMAGETYP (IMGTYPE) keywords, which Phoranso uses to differentiate between Bias/Dark/Flat/Science images. We have now added additional logic to correctly handle FITS images produced by ASIImg. 





  • We have introduced the ability to edit an existing ID Card, allowing users to add, delete or modify target and calibration stars. The new Edit command can be found in the Variable ID Card menu. For more information, please refer to the User Guide.
  • Previously, opening a FITS file in a Parallels virtualization environment on a Mac would cause the Load Catalogs operation to fail. This has now been resolved.
  • Minor enhancements





  • First order and second order Extinction correction is now supported. Full details are provided in the User Guide. Special thanks to Ken Menzies and Arne Henden for their support.
  • Han Kleijn, author of ASTAP, informed us about an ASTAP bug impacting the solving of FITS files with FOV > 2.8 degrees. This issue has been resolved in the ASTAP release of June 10th, 2024. Phoranso checks if you are using this version of ASTAP, and if not displays an appropriate warning message prompting you to install the latest ASTAP release.
  • The ASTAP solving speed in Phoranso has nearly doubled. Special thanks to Han Kleijn for his recommendations.
  • The sorting of columns in the ID Cards Manager has been re-enabled (was a regression)
  • When using Phoranso on two or more PCs, it is now possible to synchronize ID Cards between all PCs, resulting in identical Variable Star Databases. Full details are provided in the User Guide.
  • Phoranso supports tricolor DSLR and OSC FITS files (TR TG TB). They are currently converted to grayscale images. In a later version of Phoranso, we will separate the 3 color channels, allowing to analyse such FITS images by comparison to stars with R, V and B photometric magnitudes.   
  • Minor bug fixes and enhancements.





  • When defining a new ID Card, you must select one or more reference stars and optionally zero or more comparison stars. Phoranso now allows you to enable or disable selected reference and comparison stars for photometry. Enabling a star means it will be included in photometry calculations, while disabling it will exclude it from these calculations. Disabled stars still remain part of the ID Card.
    This feature is especially useful when working with variable stars with large amplitudes. It allows you to select reference and comparison stars that suit the maximum brightness of the variable star, as well as stars that suit its minimum brightness. Depending on the current state of the variable star, you can enable the most appropriate stars and disable the others without deleting them. In ID Cards created prior to version, all reference and comparison stars by default will be enabled for photometry.
    Additionally, we will soon release the capability to edit existing ID Cards, offering amongst others extra convenience for enabling or disabling stars as needed.
  • Phoranso now supports the U band, allowing photometry reports to include U band magnitudes if you have selected reference, check, and comparison stars with U band data.
  • Minor bug fixes and enhancements.





  • We added several extensions to Phoranso to convert FITS files, not compliant with the SBIG (Diffraction Limited) FITS 'standard', into compliant files. This includes the addition of mandatory keywords and the conversion of keyword values from the imperial to the metric system. With these changes, FITS files that initially could not be solved by ASTAP, PinPoint, WCSAutoSolver, etc now can be solved through Phoranso.





  • Phoranso now supports FITS files with non-standard headers created by the Skynet Terminator software of the Skynet Robotic Telescope Network
  • Fixed a bug in the File -> Settings -> Default values window. The Image height value is now correctly saved.
  • Minor improvements





  • When using the Image Math operation, Phoranso now correctly sets the DATE-OBS, EXPOSURE and JD FITS keywords of the resulting image
  • We fixed a synchronization issue with using the ASTAP solver in combination with FITS files stored on network drives
  • The Report Settings window in the Photometry menu has been extended with an option Sort observations by Filter. When selected, observations in the report files will first be sorted by Filter, and within a given Filter by JD.
  • Minor bug fixes





  • When Phoranso retrieves AAVSO VSX stars during a Load Catalogs operation, it now also displays variable stars that are listed as "Suspected" in the AAVSO VSX database
  • Minor bug fixes





  • Resolved an issue where importing LesvePhotometry Sequence files containing ATLAS comparison stars would result in errors.
  • We have extended the CBA report, in anticipation of integrating extinction and transformation corrections into Phoranso, slated for a forthcoming release
  • When creating an IDCard and hovering the mouse over a variable star, a call-out box displays relevant information about the variable star. Additionally, a right-click action triggers a pop-up menu. We've introduced a new feature at the bottom of this menu, labeled Copy name to clipboard, enabling users to conveniently copy the name of the variable star to the Windows clipboard. This functionality proves particularly beneficial when dealing with lengthy variable star names.





  • The scaling method of master dark frames during image calibration has been extended. Even if the difference in exposure time between the master dark frame and the science image is very large, Phoranso will now still apply the scaling, and proceed with the calibration process.
  • The Excel report and Photometry Settings window have been extended to prepare for the introduction of extinction and transformation corrections in a later release of Phoranso.





  • Fixed a bug in the calibration of images when working with scaled master dark frames
  • Minor bug fix in the ID Card manager when deleting an entire ID Card (screen was not properly updating).
  • To ensure consistent behavior of different Excel (MS Office) versions, we have now also implemented optimized X-axis minimum and maximum values in Excel reports, similar to the Y-axis adjustments (implemented in Phoranso





  • If a FITS file exceeds the size capacity of Phoranso, an error message will be displayed to notify the user.
  • The Excel report now features optimized Y-axis minimum and maximum values, ensuring alignment with the corresponding values displayed in the Light Curve window.





  • The Photometry Settings window now features a FILTER Keyword Mapping button, which is further explained in the User Guide.
  • An option Mouse Cursor Size has been added to the Miscellaneous tab of the File Settings form. This option allows users to select the size of the mouse cursor to be used in FITS Windows and Light curve windows.
  • Phoranso now includes a workaround to address issues encountered on certain PC configurations where the ASTAP solver produces files with erroneous RA and DEC coordinates of extracted stars. This enhancement ensures correct handling of such cases, with special thanks to Bernard Candela and Peter Frank for their valuable support in troubleshooting.
  • During Photometry, users can select the Show FITS image option to display the currently processed FITS image. Phoranso will now display the non-calibrated FITS image if the Skip image calibration option is checked; otherwise, it will show the calibrated FITS image. Thanks to Magnus Larsson for this suggestion.
  • This update also includes various minor bug fixes and enhancements to improve overall performance and user experience.
  • The User Guide has been updated to reflect above changes.





  • Updated the AAVSO Report file for Ensemble photometry to adhere to the AAVSO Extended File Format requirements. The Check star's magnitude KMAG is now reported as the calculated magnitude when working in Ensemble photometry, whereas it is reported as the instrumental magnitude in other cases. It's worth noting that while Phoranso now follows this convention, some other photometry packages may not make this differentiation. Thanks to Ken Menzies for the recommendation
  • Eliminated a dependency on a third-party package that was causing instabilities during the Load Catalogs operation on certain hardware configurations.
  • Implemented minor bug fixes to enhance overall stability and performance.





  • Extended the Excel Report with additional header information
  • Implemented small changes to the Photometry workflow
  • New version of User Guide





  • Extended the CBA Report with additional header information (including JD end date of the session, BVRI magnitudes of Ref/Check/Comp stars).
  • When doing ensemble photometry with Ensemble type set to Mean in the Photometry settings window, no reports were generated.  This regression has been fixed.





  • Added FILTER keyword to master flat images in the Master images creation command of the Calibrate files window
  • Intricate FITS images, such as those containing numerous hot pixels, often lead to solver failures. To address this, we've enhanced Phoranso with a dedicated algorithm offering failed images a second chance. This involves applying specific image processing techniques that preserve the image's photometric properties, yet often result in successfull solving. While the computation time to solve such intricate images is slightly longer, this approach eliminates the need to discard them in the photometric pipeline.
  • Fixed an issue when creating a new Variable ID Card from a DSS (Digital Sky Survey) image





  • We decided to replace the concept of "good" and "best" compstars with "Advised" compstars. The designation of "advised" is now based on the color index criterion used by the AAVSO Sequence team. Specifically, compstars (reference, check or comparison star) with a B-V color index >0.3 and <1.0 will be marked with a green circle to indicate their status. Special thanks to Ken Menzies for this valuable suggestion.
  • A bug in the Light Curve window, which incorrectly displayed the magnitude of Reference stars during ensemble photometry, has been resolved. It is important to note that this bug did not affect the generated reports, which correctly reflected the magnitude of Reference star.





  • WCSAutoSolver relies on the Gaia DR3 website for fetching astrometric data. In case of unavailability of the website, Phoranso will now present a suitable error message when the user chooses WCSAutoSolver from the File -> Settings menu.
  • Adjusted an internal setting in WCSSolver to enhance solver convergence with FITS images.
  • When creating Master image files via the Calibrate files window, Phoranso previously required FITS keyword IMAGETYP of Selected files to be set to Bias, Dark, Flat or None. Now, Phoranso accepts values of any format containing Bias, Dark or Flat. Example: when creating a Master Bias image, Phoranso will accept files with IMAGETYP set to BiasFrame.
  • Additionally, IMGTYPE keyword is now treated synonymously with IMAGETYP.
  • In the FITS Header viewer window, you can now select multiple rows and copy them to the clipboard. This can be done by pressing Ctrl-C or by right-clicking and selecting Copy from the context menu.
  • The Tools menu now includes a new option Download UCAC4 catalog,which enables users to obtain a copy of the UCAC4 catalog at any time.
  • Resolved an issue related to importing LesvePhotometry export files.
  • Fixed a bug in Excel reports occurring when the Ensemble type in the Photometry Settings window was set to Mean or Weighted Mean.




  • Executing a Load Catalog operation on a FITS image for which no APASS DR10 catalog data are available, will now result in a message box allowing the user to either switch to APASS DR6 (UCAC4) or to cancel the operation
  • WCSAutoSolver solver has been extended to better handle demanding FITS images (e.g., containing lots of hot pixels)
  • Fixed a bug in parsing the Windows folder structure during a Photometry operation
  • Added a missing link in the User Guide Star callout section in the Variable ID Card Settings chapter
  • The performance of opening Bayer Color FITS images has been improved by a factor of 2 or more.




  • First release

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Author: Tonny Vanmunster