The American Association of Variable Star Observers (AAVSO) coordinates a network of volunteer observers who contribute time-stamped estimates of the brightness of variable stars. The principle behind this effort, underway since 1910, is that statistically significant information can be derived from a large body of observations of uncertain quality. The AAVSO: “coordinates, evaluates, compiles, processes, publishes, and disseminates variable star observations to the astronomical community throughout the world. Observers send their data to Headquarters, where they are checked, processed, and added to the AAVSO International Database. [...] The AAVSO and its observers frequently provide the professional community with archival data, intensive monitoring of interesting variable stars, and target-of-opportunity event notification for coordinated observing campaigns and satellite observations."
In addition to volunteer observations, the AAVSO provides the facility for volunteers to assist with validation of observation data maintained in the observation database, through the use of a GUI-based computer program. The program allows users to visually inspect observation data in graphical form, and to flag, for further inspection, particular observations. According to the AAVSO Data Evaluation Guidelines:
The following observations could be considered “suspicious” data worthy of marking:
The AAVSO database contains about 20 million observation records. Light Curves is an automated assistant for locating candidate discrepant observations, focussing on the first two criteria listed in the guidelines above. Such an automated tool might assist human volunteer validators as a driver of their workflow, or might possibly complement their efforts.
- Positive observations more than 1 magnitude brighter or fainter than the mean
magnitude. Make sure [...] you are comparing observations made at approximately
the same time (for some stars, significant changes in behavior can occur
in a very short time.)
- Fainter-than observations that are fainter than the mean curve.
- Observations made during the “seasonal gap” of a star.
- For novae and supernovae, positive observations made before outburst.
Observations that meet any of the criteria in these guidelines may ultimately be judged as discrepant
entries, by official arbiters with the AAVSO.
This page shows a batch of candidate descrepant observations automatically generated by the application.