Please excuse the time lag, we had a holiday:
Tue, 25 Nov
Astrophysics > Earth and Planetary Astrophysics (astro-ph.EP) www.arxiv.org/abs/2511.19112
Trigo-Rodríguez, J. M. Gritsevich, M. Blum, J. Spectrophotometric evidence for a metal-bearing, carbonaceous, and pristine interstellar comet 3I/ATLAS
Wed, 26 Nov
www.arxiv.org/abs/2511.19467 (cross-list from astro-ph. IM)
Scarmato, T. Measuring Cometary Nuclei Behind Bright Comae: PSF Delta Decomposition with Bicubic Resampling and an Application to Interstellar Comet 3I/ATLAS C/2025 N1
Thu, 27 Nov
www.arxiv.org/abs/2511.20845
Roth, N. X. Cordiner, M. A. Bockelée-Morvan, D. et al. CH3OH and HCN in Interstellar Comet 3I/ATLAS Mapped with the ALMA Atacama Compact Array: Distinct Outgassing Behaviors and a Remarkably High CH3OH/HCN Production Rate Ratio
www.arxiv.org/abs/2511.20810
Eubanks, T. M. DeForest, C. E. Walsh, K. J. et al. Tracking the Activity of the Interstellar Object 3I/ATLAS through its Perihelion
Per Rahatgaonkar et al., Hutsemékers et al., Hoogendam et al., and maybe others, Trigo-Rodríguez et al. parse the interstellar object’s spectra for spectral features. As you may have gathered, this is a fertile field, and already done for Solar System comets. Just look at Roth et al.!
Roth et al., by the way, show ATLAS to be quite methanol-rich… yet not unprecedentedly-so. The comet is still within bounds of Solar System comets, just at the high end.
Scarmato has a new comet algorithm, Solar System or not. Applying the image-processing technique to ATLAS just happens to be a timely demo.
Finally, Eubanks et al. give their lightcurve (brightening and dimming over time) of the comet (like other groups). Like other comets, emissions (and thus reflectivity) rise as the object approaches the Sun, and warms. We are now near perihelion, and the comet should be it warmest and most active. As it passes perihelion and recedes, it should cool, decline in activity, and decline in brightness. The particulars are what’s important: different volatiles boil at different temperatures, changing the time series.