Parameter estimation using 2σ upper limits
It turns out they could be as massive as 200-2,000 Jupiter-masses – it means scientists used calculations to find limits on the masses of these worlds.
Technical definition
This technique involves constraining parameters (such as planetary mass) by assigning a confidence interval, usually represented by 1σ ± δx or 2σ ± δy, where δx and δy are the corresponding uncertainties.