Skip to main content



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.

Transforms: Everything you need to transform your CCD observations

This page serves as a central location for the tools AAVSO voulnteers have developed and promulgated to help fellow photometrists transform their observations, making them compatible and more useful to the professional astronomy community.

These include:

AAVSO CCD School Videos

The AAVSO is now offering you the opportunity to purchase streaming videos of the popular CCD school taught by former Director Arne Henden during the summer of 2014.

CCD Resource and Reading List

This page is a work in progress. Please help by suggesting more resources and reading material.

Suggested Stars for CCD Observers

If you are a CCD observer the Universe is your oyster. Nearly all the AAVSO program stars can and should be observed with CCDs and science filters. The primary advantages of CCD detectors over visual observers are the potential for very high precision photometry, which facilitates detecting very minute light changes, and the ability to record much fainter stars.

Long Period Variables

AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484