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.
Here you will find a list of software that has been developed both by and for the AAVSO. This runs the spectrum from both data entry and data gathering software – still very important for what we do – and data analysis software to enable you to move forward and interpret the data you gather.
Observation Manager  - Manage your observations and export them into the official Visual Format of the AAVSO. This software is written in Java so can run on any platform (Windows or MacOS). Created by Dirk Lehmann (LDI).
Excel Spreadsheet  (Converts BAAVSS to AAVSO and VSNET formats) - by Gary Poyner
This Excel spreadsheet will take visual observations submitted in the BAAVSS format and export them to VSNET and AAVSO formats. Special thanks to Gary Poyner for providing this spreadsheet to the public.
Excel Spreadsheet (Creates AAVSO or VSNET format reports) - Erwin van Ballegoij's version of Gary Poyner's spreadsheet. Zipped files available as: Data_Entry.xls  and Data_Entry.xlsx  (updated 23 September 2013)
Enter visual observations and export as AAVSO or VSNET format. Many thanks to Erwin for providing this spreadsheet.
A program that converts VSNET format observations to AAVSO format observations. You also can download the documentation  as well as a the needed list of program stars .
OBSVAR V1.5  - Link to web page by Laurent Corp
OBSVAR.TXT  - (Readme file)
This is a link to an observation planning tool created by Laurent Corp (CLZ). It will search the AAVSO or AFOEV Bulletins and extract data that meets different criteria such as Constellation, Month, Right Ascension, etc. The web page is in French and there is an English option available. This software is not officially supported by the AAVSO and any questions should be directed to the author.
VaST  - 2/6/12
VaST (the Variability Search Toolkit) is a UNIX/LINUX based program designed by Kirill Sokolovsky aimed at finding objects of variable brightness on a series of astronomical images. The Tookit has been successfully used by several AAVSO members to aid in published analysis and the discovery of new variable stars.
CLEANest  - 3/10/05
This is Visual Basic source code for the CLEANest and SLICK algorithms in TS. Cleanest is an effective method for removing false peaks from a power spectrum and can also describe and detect multiperiodic signals. (Foster G., AJ Vol 109, Nr 4, April 1995 "The cleanest Fourier spectrum")
PhasPlot 2.0  - Version 2.0 released June 26, 2009
PhasPlot is a Windows-based tool for plotting phase diagrams of variable star data. The user interface is designed to make it easy to test different periods on a star. PhasPlot is designed to work with data from the AAVSO International Database downloaded via the official form to download data without any reformatting of the data needed.
Windows software to display and analyse light curves using AAVSO data
Rcodes . Release Date: 7/15/2010
This set of software, in the statistical language "R," is meant to accompany Grant Foster's book, Analyzing Light Curves: A Practical Guide.
TS (Fortran)  Release date: 4/6/04
A Fortran based time series statistical program that enables you to analyze variable star data.
TS (DOS)  Version 1.2
MS-DOS based time series statistical program that enables you to analyze variable star data.
WWZ (Fortran) 
A Fortran based time-series analysis program used to study the time-evolution of variable star data, capable of measuring changes in period, amplitude, and mean magnitude.
WinWWZ (Windows VB.Net) 
A VB.Net based time-series analysis program used to study the time-evolution of variable star data, capable of measuring changes in period, amplitude, and mean magnitude. Click here for more information about WinWWZ .
WWZ and TS Bundle (Fortran)  Release date: 4/6/04
Download the Fortran versions of both TS and WWZ all at one time.
VStar . Release date: Current
A free, java-based, open-source variable star data analysis tool.
A Java-based data entry program for reporting sunspot counts to the Solar Section. Please use this for your reports.
Software, by Bob Nelson 
Programs range from finding times of minima to intermediate processing of spectral data (no IRAF!)
Introduction to: AAVSO and How to Make a Visual Estimate 
A 2.5 Megabyte powerpoint presentation created by Chuck Pullen, AAVSO member, that introduces you to the AAVSO and shows you how to estimate the magnitude of a variable star. There is also a Spanish translation of this presentation by Jaime Garcia: ¡Aprenda cómo divertirse haciendo observaciones de estrellas variables! 
and a Chinese version by Tao Fan-Lin: 變星觀測練習 
Gamma Ray Burst Presentation 
A 3.5 Megabyte powerpoint presentation created by Chuck Pullen, AAVSO member, that introduces you to Gamma Ray Bursts and the AAVSO Gamma Ray Burst Network.
HOAFUN 2.0 
A Windows version of the DOS-based program distributed with Hands-On Astrophysics . This is a great tutorial for making variable star observations. It has a game, examples, and even prints out an award certificate for completion of the game. For Windows 95 and up. It was written for junior high through high school but applies to anyone just beginning variable star observing.
Information on the UNIX planetarium software support for AAVSO light curves.
Variable Star Search Utility 
Open source freeware designed for Windows that gives you much more control in searching for variable stars. Check out how easy and useful it is today. New version released: 5/26/08
AstroPlanner: Astronomical Planning and Logging Software 
A software application for Macintosh and Windows computers that facilitates astronomical visual observation planning and logging as well as control of Meade telescopes that use the LX200, LX200GPS or Autostar controllers, Celestron NexStar scopes, Astro-Physics GTO mounts, the Vixen SkySensor 2000 system , and several others. This item is shareware and costs $20 to register.
An application which is able to generate a finder chart for a given variable star (like planetarium software), is able to show the AAVSO observing chart with comparison stars, allows the recording of observations and generates reports in AAVSO format. Be sure to download the latest version.
An interactive version of the AAVSO Bulletin for LPV's. Use it to search for information about particular variables and to plan your observing sessions.
Signal-to-noise calculator for CCD photometry 
Excel spreadsheet developed by Michael Newberry
Nemesis companion star remover for CCD photometry 
Excel spreadsheet developed by Lew Cook
Transforms: Everything you need to transform your CCD observations 
This link will take you to a page that contains useful programs for both computing your transformation coefficients and applying the transforms to your observations. A prodigious amont of work has been done by volunteers Gordon Myers, George Silvis, and Richard Sabo to develop these tools.
Increasingly astronomers are turning to utilities on smartphones and tablets to augment their computational capabilities in the field. Below are some utilities we've found useful for variable star activities.
Variable Stars 
by Diatom Software. This iPhone app is a mobile catalog of over 183 thousand stars that vary in brightness over time.
Astro Time 
by Diatom Software. This iPhone app is an astronomical clock designed for field use by amateur astronomers. It includes your local date and time, Greenwich Mean Time (GMT), Local Sidereal Time (LST), and Julian Date (JD) with up to six decimal point precision.