Hubble Space Telescope / WFC3 camera images used to determine the orbit of the satellite of the dwarf planet Gonggong (2007 OR10). We later suggested the name Xiangliu for the satellite (Kiss et al, Icarus, 334, 3, 2019)
The asteroid belt, the interplanetary dust cloud and the small bodies in the trans-Neptunian region are the leftovers of a once much more massive disk that formed the planets about 4.5 billion years ago. Our group’s focus is mainly on these small bodies and their connection to the formation conditions in the early Solar system.
The webpage of the group can be found here.
Two important results:
1. Light-curves of trans-Neptunian objects with the Kepler Space Telescope
Kecskeméthy, V., Kiss, Cs., Szakáts, R. et al. Light Curves of Trans-Neptunian Objects from the K2 Mission of the Kepler Space Telescope, The Astrophysical Journal Supplement Series, 264, 18, 2023, https://ui.adsabs.harvard.edu/abs/2023ApJS..264...18K/abstract
Light curves, i.e. periodic brightness variations of asteroids, are caused by the rotation of the object as we see it each time from a different angle and therefore we see a different amount of reflected sunlight. The K2 mission of the Kepler space telescope allowed the observations of light curves of small solar system bodies (asteroids) throughout the whole Solar System, and in our latest work we investigated K2 observations of 66 trans-Neptunian objects. Due to the faintness of our targets, the detectability rate of a light-curve period was ~56%, notably lower than in the case of other small-body populations observed in the K2 mission, like Hildas or Jovian Trojans which are much closer to the Sun. We managed to obtain light-curve periods with an acceptable confidence for 37 targets; the majority of these cases are new identifications. We were able to give light-curve amplitude upper limits for the other 29 targets. Several of the newly detected light-curve periods are longer than ~24 hr, in many cases close to ~80 hr; i.e., these targets are slow rotators. This relative abundance of slowly rotating objects is similar to that observed among Hildas, Jovian Trojans, and Centaurs in the K2 mission, as well as among main belt asteroids measured with the TESS space telescope. This draws a very different picture of the rotational characteristics of trans-Neptunian objects compared with the earlier ground-based observations, notably affecting the formation and collisional evolution theories of these bodies. Trans-Neptunian objects also show distinctively higher light-curve amplitudes at large (D ≳ 300 km) sizes than found among large main belt asteroids, in contrast to the general expectation that due to their lower compressive strength, they reach hydrostatic equilibrium at smaller sizes than their inner Solar System counterparts.
