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VPhot is a member benefit of the AAVSO! Click here to join!

VPhot is an online tool for photometric analysis. You can upload your own FITS images to VPhot or have images taken via the AAVSOnet robotic telescope network automatically sent to your VPhot account.

To use VPhot you must:

All VPhot processing is done via a web browser. All of the basic photometry tools exist (stacking, time series analysis, control of annulus', transformation, etc.) and the algorithms have been rigorously checked and confirmed to be of the highest quality. Results of the processing are automatically exported in AAVSO Extended Format, meaning you can directly load them into our database via WebObs without having to make any changes to the data file. 

Please note that your images will be retained on the server for four months. After this time, they will be deleted automatically to save resources.

 Members can download the VPhot Users Guide.

 We also have an online VPhot Forum for your questions, comments and suggestions.

The following series of video tutorials have been produced by Ken Mogul. Some features may have changed since the tutorials were produced, but the core lessons are still applicable.

VPhot was originally published under another name. Click here to read why we ultimately chose the name VPhot.

VPhot is primarily the work of Geir Klingenberg (coding and design) and Arne Henden (photometry) with a cast of hundreds who have made suggestions, written tutorials and tested the software.

Software Directory

Increasingly, software and data analysis are becoming the heart of what we do as astronomers, even amateur astronomers. More and more a lot of our data gathering is being handled by orbiting satellites and robotic telescopes. It is up to the human beings in the equation to analyze and interpret the results.

SID Data Grabber

The SID Data Grabber is an application to help prepare an AAVSO SID report file from your Stanford/SARA superSID monitor log files. It offers a zoomable graphical view of the log data where you can click the graph to grab the times then puts them into the AAVSO format report file, ready for submission at the end of the month.

Variable Star iPhone App Now Free

The Variables Stars and AstroClock iPhone apps are now available for free. Thanks, Diatom software!


WinWWZ is a Windows XP-based tool for period analysis of variable stars or other time series data using wavelets. It is designed to work with data from the AAVSO International Database downloaded via the official form to download data but will work with most generic time series data sets and supports flexible input formats.


Software Agreement


AAVSO software and documentation are copyrighted by the AAVSO.

Software that exports AAVSO format

Exports to Visual Format:

Exports to Extended Format:

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