The Asteroid Lightcurve Data Exchange Format (ALCDEF) was introduced at the 2010 Division of Planetary Sciences meeting. The idea is to standardize minimum data requirements and format so that exchanging data sets among researchers is as simple as possible.

There is also a Simple ALCDEF (S-ALCDEF) format for those wanting to upload legacy data or from programs that do not generate full ALCDEF files with a minimum.

Download the combined ALCDEFand S-ALCDEF standards document.

The ALCDEF initiative also includes storing data on a long-term, centralized system that will be regularly maintained. The site is now privately hosted and there is a mirror of the MySQL database on a virtual machine at the NASA Small Bodies Node in Tucson, AZ.

The ALCDEF site displays the individual plots for submitted data as well as a phase angle bisector longitude plot that highlights the longitude for a selected lightcurve. This allows determining the breadth of coverage (different viewing aspects) for modeling as well as planning observations.

Individual lightcurve blocks or the entire set for a given asteroid can be downloaded as a ALCDEF-compliant file.

It is vital that asteroid photometry be recorded for posterity.
Lightcurve data can be used to determine rotation periods and model the spin axis and/or shape of an asteroid. Far too much of past data are in disarray, following any number of formats, if available at all.

Please consider submitting your data to the ALCDEF database as soon as possible.

ALCDEF web site