ZTF DR21 lightcurves in parquet format. There are 1,181 field subdirectories, 
containing a total of 176,218 parquet files (one for each field / chip / 
quadrant / filter combination).

File content and format are documented in section 12c of the release notes:
https://irsa.ipac.caltech.edu/data/ZTF/docs/releases/dr21/ztf_release_notes_dr21.pdf

To read parquet using python/pandas:
https://pandas.pydata.org/docs/user_guide/io.html?#parquet

The parquet files can be verified on a Unix/Linux OS using:
"md5sum -c checksum.md5"

Total volume: ~ 6.7T

Lightcurve statistics in g-filter:
Number of lightcurves with >=  1 epoch :   1,538,138,540
Number of lightcurves with >=  2 epochs:   1,262,333,551
Number of lightcurves with >=  5 epochs:   1,046,080,085
Number of lightcurves with >= 10 epochs:     925,887,178
Number of lightcurves with >= 20 epochs:     799,357,387

Lightcurve statistics in r-filter:
Number of lightcurves with >=  1 epoch :   2,403,654,314
Number of lightcurves with >=  2 epochs:   2,068,020,423
Number of lightcurves with >=  5 epochs:   1,759,780,669
Number of lightcurves with >= 10 epochs:   1,580,723,196
Number of lightcurves with >= 20 epochs:   1,391,366,327

Lightcurve statistics in i-filter:
Number of lightcurves with >=  1 epoch :     945,057,256
Number of lightcurves with >=  2 epochs:     799,417,676
Number of lightcurves with >=  5 epochs:     683,591,920
Number of lightcurves with >= 10 epochs:     609,339,641
Number of lightcurves with >= 20 epochs:     516,126,174

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Last modified: 2024-05-15