ASASSN-24fw: Candidate circumplanetary disk occultation of a main-sequence star
Nadia L. Zakamska, Gautham Adamane Pallathadka, Dmitry Bizyaev, Jaroslav Merc, James E. Owen, Kevin C. Schlaufman, Karolina Bk{a}kowska, S{l}awomir Bednarz, Krzysztof Bernacki, Agnieszka Gurgul, Kirsten R. Hall, Franz-Josef Hambsch, Krzysztof Kotysz, Sebastian Kurowski, Alexios Liakos, Przemys{l}aw J. Miko{l}ajczyk, Erika Pakv{s}tien.e, Grzegorz Pojma’nski, Adam Popowicz, Henrique Reggiani, Daniel E. Reichart, {L}ukasz Wyrzykowski, Justas Zdanaviv{c}ius, Micha{l} .Zejmo, Pawe{l} Zieli’nski, Staszek Zola
arXiv:2507.05367v1 Announce Type: new
Abstract: Dusty disks around planets in outer reaches of exo-planetary systems can be detected as long-lasting occultations, provided the observer is close to the planet’s orbital plane. Here we report follow-up observations of ASASSN-24fw (Gaia 07:05:18.97+06:12:19.4), a 4-magnitude dimming event of a main-sequence star which lasted 8.5 months. Using optical spectroscopy with KOSMOS (APO), MagE (Magellan) and GHOST (Gemini-S), we find strong Na I D absorption indicating that the occulter is gas rich. We detect multiple low-ionization metal emission lines with velocity dispersion 2 Gyr), the disk is unlikely to be a survivor of the planet formation stage and is more likely to be a result of a planetary collision. If Na D absorption and metal emission lines originate in the circumplanetary disk, the observations presented here are the first discovery of a planet-driven wind or of circumsecondary disk rotation.arXiv:2507.05367v1 Announce Type: new
Abstract: Dusty disks around planets in outer reaches of exo-planetary systems can be detected as long-lasting occultations, provided the observer is close to the planet’s orbital plane. Here we report follow-up observations of ASASSN-24fw (Gaia 07:05:18.97+06:12:19.4), a 4-magnitude dimming event of a main-sequence star which lasted 8.5 months. Using optical spectroscopy with KOSMOS (APO), MagE (Magellan) and GHOST (Gemini-S), we find strong Na I D absorption indicating that the occulter is gas rich. We detect multiple low-ionization metal emission lines with velocity dispersion 2 Gyr), the disk is unlikely to be a survivor of the planet formation stage and is more likely to be a result of a planetary collision. If Na D absorption and metal emission lines originate in the circumplanetary disk, the observations presented here are the first discovery of a planet-driven wind or of circumsecondary disk rotation.