What is ALCDEF?About Asteroid LightcurvesAcknowledgementsCreditsData and Privacy Policy

Special Annoucements

Download and review the latest ALCDEF standards PDF.

2024 March 4
The site and standard have been updated to distinguish between Pan-STARRS and Sloan ugriz filters and magbands. "Px" stands for Pan-STARRS wile "Sx" stands for Sloan. Magnitudes based on the ATLAS star catalog (Tonry et al., 2008) are Px

The EPOCH keyword has been deprecated and replaced by EQUINOX. Existing programs that generate EPOCH will still work as will upload files using EPOCH. If using a custom program to read/write ALCDEF files, it should be updated to use EQUINOX.

Statistics and Search

 Objects  LC Blocks  Observations 
Last update: 2024-07-14 08:15:48

Object Search

Required "Opt-in" and File Upload

You must give express permission before your data can be stored and distributed. Without this permission, your data will not be accepted by the ALCDEF site. You must also choose whether or not your data will be automatically made part of a periodic release from the NASA Planetary Data System.

For more information, see the Data and Privacy Policy statement and the ALCDEF documentation.

Allow sharing       Submit to PDS 




ALCDEFVerify is a web-based tool that runs the same verification checks used when uploading files to the ALCDEF database. It was developed for those writing third-party programs or scripts to debug and validate their data prior to uploading the files to the ALCDEF database.

Up to three files can be processed during each run.
It is strongly recommended that each file be < 1 MB.

Defined Constant Keywords
(see section 3 of ALCDEF standards documentation)


S-ALCDEF is for those who have basic text data files, e.g., JD, magnitude[, magerror]. Usually with a minimal amount of editing, these files can be uploaded to the ALCDEF database without creating the more detailed and rigorous standard ALCDEF files.

See the ALCDEF documentation for details
Click here to go to the S-ALCDEF upload page

N.B. If using Gaia G magnitudes, you must set MAGBAND=GG (Gaia G). The single-letter 'G' can be confused with the Sloan g magband. There is no 'G' filter, so use FILTER=X, where X is one of the accepted filters.

Archive Download

Full Download

Custom Download

Download Notes

Latest ZIP with all ALCDEF data
Created: 2023 September 27 @ 22:02:13
Size: 128,019 KB

yyyy-mm-dd or yyyymmdd


If successful, a ZIP file is created that contains only those lightcurve blocks that were added or edited on/after the date given above and a download link appears above the Sumbit button.

Due to the heavy load required to generate the ZIP, custom downloads are limited to no more than the last 90 days.

Do not press any buttons or leave the page while waiting for the file to be generated.

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