Happy Samhain, All Saints Day, etc. to all who celebrate. Speaking of things coming from Europe, good Astronomy & Astrophysics for October (vol. 702):
Santana-Ros, T. Ivanova, O. Mykhailova, S. et al. Temporal evolution of the third interstellar comet 3I/ATLAS: Spin, color, spectra, and dust activity L3 202556717
Beaugé, C. Gianuzzi, E. Trógolo, N. et al. A formation mechanism for narrow rings around minor bodies L15 202556383
Shober, P. M. Determining the statistical significance of meteorite–asteroid pairs using geocentric parameters A36 202555857
Sun, C. Zhang, X. Zeng, X. et al. Revealing the loss of sulfur on troilite under simulated solar wind H+ irradiation A81 202555234
Agrusa, H. Chatenet, C. Gravitational scattering of ejecta in the Didymos system cannot explain the evolution of the binary’s orbital period A122 202555772
Krugly, Y. Golubov, O. Kyrylenko, I. et al. Contact binary asteroid (153201) 2000 WO107: Rotation, shape model, and density A170 202452553
Fornasier, S. El-Bez-Sebastien, N. Spectrophotometry of Jupiter Trojan with the Gaia DR3 catalog A193 202555999
Balossi, R. Tanga, P. Delbo, M. et al. An ancient L-type family associated with (460) Scania in the middle main belt as revealed by Gaia DR3 spectra A239 202555527
Dybczyński, P. A. Królikowska, M. Update of the CODE catalogue and some aspects of the dynamical status of Oort Cloud comets A143 202556678
Santana-Ros et al. I covered as a preprint… now A And A has made it officially a “print”.
Beaugé et al. cover a timely and interesting topic- rings have been found around multiple small bodies. What are the dynamics of ring systems in weak gravity fields, around possibly irregular primary bodies, possibly perturbed by Saturn, Uranus, etc.? Very interesting.
We sometimes claim parentage- ‘particle X was shed from host body Y’. Meteor showers come from some comets, and for visible, obvious showers, we have the statistics to speak with confidence. But what of asteroids that shed material, sometimes becoming meteors and meteorites? The low activity of even the most active asteroids hurts the statistics- we must speak with due care, not confidence.
Asteroids contain many sulfides. These minerals are not refractory, less stable than most. Under space weathering (micrometeorite bombardment, solar wind, cosmic rays, etc.), sulfides will be altered. How? Sun et al. do the experiment- might it explain active asteroid (3200) Phaethon?
Agrusa et al. I touched on before. The DART project deflected Didymos, but how much? After the initial impact and assessment, Didymos continued to shift slightly. Agrusa et al. rule out one mechanism for that second-order effect; this may be necessary for a real Earth defense mission.
Speaking of binaries, we see another: WO107. Each new binary gives us clues. Here, WO107 is a contact binary- the two objects have come back together, forming a ‘peanut’ shape, apparently. What is the history of this recontact?
Gaia: truly, the mission that keeps on giving. From its vantage point, far from Earth eclipses or other disturbances, the craft steadily trickled back data on astronomical object after object after object, and with a crude color index, too. Some of those (well, lots) were Trojan asteroids.
Speaking of asteroid collections, some are no accidental collections. Apparently, bodies near (460) Scania (and not-so-near) are fragments of it, scattered when Scania had an impact event. If so, they should have similar compositions, after all. But Scania appears to be a K-type asteroid, while these fragments look L-type. Might that be a clue to that composition(s)?
The CODE catalog collects comets. Lots of comets. Meanwhile, we have no direct, observational evidence for the Oort Cloud, thousands of AU away. Do we have enough long-period comets to say something- even something statistical- about the Oort Cloud now?