This ATLAS100 data release (v1.0) consists of the light curve data and a catalog csv file for the ATLAS100 sample of 1729 transients within ~100 Mpc (Srivastav et al. 2026).

The LCdata folder contains the binned (1-day) and cleaned ATLAS light curves. The light curve data was produced from ATClean, and the columns are described in the ATLAS forced photometry webpage (https://fallingstar-data.com/forcedphot/resultdesc/).

Baseline Correction
A baseline correction for the ATLAS light curves was computed for each transient, and a constant offset was applied if the computed baseline correction was significant, i.e. offset_uJy > 5 * offset_err_uJy. The offset was computed from a 200-day pre-discovery window (-220 to -20 days since TNS discovery). If the data was insufficient in the pre-discovery window, a late-time window (+500 to +700 days) was used (details in the paper).

The original ATClean output (not baseline-corrected) is included in the data release, along with the baseline corrected data for completeness. Each directory includes the original and corrected data (separated by filters - orange and cyan), as well as png plot(s) showing the light curve with and without the correction (if applied). A baseline correction was applied only to 275 light curves of 246 unique transients (out of 3449 light curves for 1729 transients). In case a baseline correction was not needed, the 'corrected' file is then just a copy of the original ATClean output, but we include both data products for consistency.

We recommend using the baseline corrected data, e.g. 2017gmr.o.1.00days_zp_corr.lc.txt is the o-band, corrected data for SN 2017gmr. However, if the user wants to perform a custom baseline correction, the original ATClean output is also provided (e.g. 2017gmr.1.00days.lc.txt).