The observation/publication cycle is getting into a groove:
Astrophysics > Earth and Planetary Astrophysics arxiv.org/abs/2509.02813
[Submitted on 4 Sep 2025]
Frincke, T. T. Yaginuma, A. Noonan, J. W. et al. Near-Discovery SOAR Photometry of the Third Interstellar Object: 3I/ATLAS
arxiv.org/abs/2509.03361
[Submitted on 4 Sep 2025]
Guo, Y. Zhang, L. Feng, F. et al. Search for Past Stellar Encounters and the Origin of 3I/ATLAS
Activity: the faint and changing emission and brightening of comets (and some asteroids). Frincke et al. do their part to track our little interstellar fellow in time and in coma composition. Since gas composition tells us of chemical makeup, we are on track to see (even if faintly) the makeup of some other star system. This is a preprint, sure, but a straightforward one.
Guo et al., meanwhile, do their part to track ATLAS back to some other star system. Space is overwhelmingly empty, so following 3I’s trajectory may sound simple. But these low-mass bodies can be perturbed by passing a star, so the galaxy forms a gigantic billards table- ATLAS may have got to us by way of a ‘bank shot’. This arXiv claim is, understandably, more vague.