The following objects are high-confidence transient objects detected in the 90-220 GHz band by SPT-3G and is updated as new objects are found. Objects listed here have a signal-to-noise ratio of at least 6.5, at the level of one false detection per year from noise. Possible sources of other false detections are weather balloons and instrument glitches, which rarely pass checks in low signal-to-noise detections.

Frequent source classes detected are stellar flares, flares from AGN below our threshold (here 10 mJy) in their quiescent state, and asteroids. Where known, event classification is indicated in the "Additional Information" column.

Provided light curves and fluxes use a preliminary calibration and may be shifted by up to 20%. Source position uncertainties are also preliminary and may be shifted as much as 0.1 arcmin. The "1-year" lightcurve plots show week-averaged flux densities from Feb - Dec for each observing year. The "2 weeks at peak" lightcurves show flux densities measured in single observations over the most recent 2 week period.

For more information, please consult Guns et al. 2021 (ArXiv:2103.06166). Please direct questions to spt_source_help@box.uchicago.edu. The SPT transient alert system is supported by NSF grants AST-1716965 and OPP-1852617.