Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.07584

Discovery of 2 km ultra-fast rotating asteroid in Rubin DP2 catalog via varying Fourier order method

Dmitrii E. Vavilov·Siegfried Eggl·Sarah Greenstreet
View original source ↗Read source document ↗Export metadata ↓

Abstract

Time-resolved photometry from large surveys can yield rotation periods for huge numbers of asteroids, but only if the reliability of each period is assessed automatically, since sparse and irregular sampling produces many false periodogram minima. We present an improved method that determines asteroid rotation periods with a Fourier series whose order is chosen for each object individually. This has substantial advantages over lower order methods, especially when unique solutions for the spin period cannot be reliably determined. In such cases, the method reports the set of alternative periods together with the corresponding probability estimates. We apply the improved spin period determination method to the NSF-DOE Vera C. Rubin Observatory Data Preview 2 (DP2) catalog of solar system objects and determine reliable periods for a large sample of asteroids. Among them we find 66 super-fast rotators, which spin faster than the classical 2.2 h spin barrier. Two of them are remarkable: asteroids 491384 and 566130 are both larger than 2 km, yet they complete a full rotation in only about five minutes. To survive such a fast spin, they must have significant internal cohesion. At a diameter of about 2.5 km, asteroid 491384 is the largest ultra-fast rotator known so far.

Explore related subjects

astro-ph.EPastro-ph.IM

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Dmitrii E. Vavilov, Siegfried Eggl, Sarah Greenstreet. 2026-10-06. Discovery of 2 km ultra-fast rotating asteroid in Rubin DP2 catalog via varying Fourier order method. https://arxiv.org/abs/2610.07584

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Companion architectures of sub-Saturns: Distinct migration pathways across the Neptunian landscape

Close-in sub-Saturns (4.0 - 8.5 R$_\oplus$) are depleted in the Neptunian desert, accumulate in a narrow overdensity near P = 3.2 - 5.7 d (the Neptunian ridge), and thin out into the more moderately populated savanna at longer periods. We test whether sub-Saturns have systematically different companion architectures, as predicted if desert and ridge planets arrived through high-eccentricity migration while savanna planets migrated quiescently. We compile 86 systems with both transit and RV data, construct completeness maps and combine them into detection probability surfaces for companions. The combined completeness maps are used to calculate companion occurrence rates across different companion types with a joint Poisson occurrence model. Companion architectures differ significantly across the landscape. $91.1_{-4.3}^{+3.2}\%$ of savanna sub-Saturns have nearby companions (P < 200 d) compared to only $36_{-14}^{+16}\%$ of desert and ridge sub-Saturns. This contrast is driven almost entirely by small ($M_\mathrm{c} < 20\,\mathrm{M}_\oplus$) companions, which accompany $88.2_{-5.5}^{+4.2}\%$ of savanna but only $29_{-14}^{+17}\%$ of desert and ridge sub-Saturns, while medium-mass and giant companions within 200\,d are rare ($\lesssim 13\%$) everywhere. Savanna sub-Saturns moreover typically reside in compact multi-planet systems. These contrasts are robust to crosscuts in sub-Saturn radius, bulk density, eccentricity, and host-star properties. Desert and ridge sub-Saturns reside in dynamically emptied systems whose nearby companion rates match those of hot Jupiters, while savanna sub-Saturns inhabit compact multi-planet systems resembling those of warm Jupiters. This parallel supports two migration channels operating within a single population: HEM delivering planets to the desert and ridge, and quiescent disk migration or in-situ formation populating the savanna.

astro-ph.EP↗
arXiv2026

Irradiated Atmospheres VII. Effect of Mixing Energy Flux on Atmosphere-Interior Coupling

Highly irradiated, underdense rocky planets such as puffy Venuses may host strong coupling between their atmospheres and magma-ocean interiors. Previous studies have mainly treated this coupling through radiative transfer and chemical equilibrium, leaving the role of vertical mixing unclear. Here we quantify how energy transport associated with vertical mixing modifies the thermal structure, volatile chemistry, and emission spectra of puffy Venuses. Atmospheric circulation and gravity-wave breaking are possible dynamical sources of such transport. We show that this energy transport provides an additional greenhouse-like heating pathway by warming the deep atmosphere, thereby increasing the pressure and temperature at the magma-ocean surface. The resulting thermal changes also reshape the atmospheric composition, especially the abundances of \ce{CO} and \ce{H2O}, and change the partitioning of C-, H-, and O-bearing volatiles between the atmosphere and the magma ocean. Moreover, these changes reshape the mid-infrared planet--star flux ratio, especially at low equilibrium temperatures and in higher-mass planets. Under high C/O, it slightly increases the flux near $3.5$--$4.0\,μ$m, but more broadly reduces atmospheric transparency and suppresses the flux. This may affect radius estimates for puffy Venuses over a limited temperature range.

astro-ph.EP↗
arXiv2026

Hubble Space Telescope Observations of Active Asteroid (101955) Bennu

Measurements from NASA's OSIRIS-REx spacecraft revealed (101955) Bennu as a member of the active asteroid class. These objects exhibit transient, comet-like activity, commonly producing particle trails best observed from a vantage point close to the projected orbit plane. Accordingly, we obtained deep, high resolution observations of Bennu at orbit plane crossing in 2023, using the Hubble Space Telescope. We find no evidence for ejected material, and place model-dependent limits to the mass loss of dM/dt < 0.12 kg/s from an analysis of the near-nucleus surface brightness profiles and dM/dt < 6e-3 kg/s from the absence of a measurable particle trail. These limits are one to two orders of magnitude smaller than rates of mass loss measured remotely in other active asteroids and raise the possibility that low activity in many or most asteroids might fall beneath the prevailing thresholds offered by remote observations. Taking a still smaller mass loss rate estimated from OSIRIS-REx data, we calculate a specific rate L = 1e-7 kg/km2/s and extrapolate to the entire main-belt asteroid population. We estimate a cumulative dust production rate 850/r_min**1/2 [kg/s], where r_min is the minimum asteroid radius in meters. For r_min > 1 m, this is <1% to 10% of the rate needed to sustain the Zodiacal cloud in steady state.

astro-ph.EP↗