A number of papers have been written discussing visual magnitude estimates in comparison to photometry.  Multiple studies have shown that visual magnitude estimates compare very favorably with instrumental photometry in terms of sensitivity and consistency.  As with all data, care must be taken to understand what visual magnitude estimates represent, what their bandpass is, and when their use is appropriate.

The AAVSO now distributes its published times-of-minimum data for eclipsing binary in single compressed files (.tgz and .zip), rather than as a searchable online index.  For data on a specific star, unzip the compressed file, and search for the star's name among the included text files.  These files contain updated publication information through November 30, 2005, the time at which the files were last updated.

Data Validation

The AAVSO Data Validation Project was a two-year project begun in 2002 where AAVSO staff examine every visual observation in the AAVSO International Database made between 1911 and 2001.  This project has been completed, and all AAVSO Light Curves are now available directly via the AAVSO Website.  A summary of the Validation Project was published by Malatesta et al. in the Journal of the AAVSO, volume 34 (2006).

Digitizing Olin Eggen's Legacy

Quick link: want to get involved? Visit the Eggen Data Project

1. JD: The Julian Date of the observation.
2. Magnitude: The magnitude estimate of the observation. A < sign means it was a null observation "fainter than" the magnitude given.
3. Uncertainty: Uncertainty (error) of the observation as submitted by the observer
4. HQuncertainty: Uncertainty (error) of the observation as calculated by AAVSO Headquarters
5. Band: Bandpass of the observation.

In the 1980s, the AAVSO began a monumental project to completely digitize the paper and punchcard records of the AAVSO.  This project, undertaken just as computers became more common and easy to use, foreshadowed the rapid advancement in networking technology that led directly to the world wide web, and to the AAVSO website.  As a result of the work the AAVSO did, we are now able to serve our archive of over 18 million observations to the entire world via our website, providing decades worth of variable star observations for thousands of different variable stars to researchers world-wide.

Overview: Long-term visual light curves

This page gives background on our long-term visual data archives, with an emphasis on our data holdings for different classes of variable stars.  It is meant to give an overview of the AAVSO International Database (AID) to researchers interested in studying a number of different light curves of a given class, or who are interested in a summary of what the AAVSO's visual data archives have to offer.

This is a short guide for researchers interested in analyzing data from the AAVSO International Database (AID).  It is intended to be an introduction to the data found in the AID, as well as a guide to help you begin utilizing these data in your research.  Data in the AID are heterogeneous in nature, and all users of AAVSO data are encouraged to work with the AAVSO to ensure that the data are being interpreted correctly.  All researchers are encouraged to contact the AAVSO at any stage of the

The AAVSO Data Access portal

Go to Data Download.
Go to WebObs (search observations).
Go to Light Curve Generator.
Go to MyNewsFlash.
Go to Data Usage Guidelines.
Go to Information about AAVSO Data.