In the Planetary And Space Science December 2025 issue (vol. 269):
Gorshanov, D. L. Sokova, I. A. Petrova, S. N. et al. Testing the binarity of asteroid (720) Bohlinia using lightcurve analysis Art 106217 .2025.106217
We think there’s a satellite around asteroid (720) Bohlinia… think. How do we know? It’s a dot of light in the sky, but that dot brightens and dims (a “lightcurve”) in a certain pattern. A perfectly round, even sphere would never brighten and dim; a potato does, when it turns endwise to longwise and back. A potato with a companion then adds irregular dips and peaks, as that companion alternately adds or subtracts its light to the dot.
Every rotation gets us more data; you can bet astronomers watch these bodies for far more than just one rotation. Watching them over half an orbit then adds ‘season’ data; you can imagine we’d like to confirm more than one-half orbit as well. Given enough tracking, we can statistically say which “dips” and “peaks” are more likely to be real, and not noise in the data. Gorshanov et al. think they have enough tracking.