arXiv subjects

Leonard Kornoš

Publications and source records attributed to Leonard Kornoš.

16 recordsLinked to original sources

arXiv2026

Achondrites in meteor data: Spectra, dynamics, and physical properties of candidate aubrite and eucrite impactors

Meteor spectroscopy presents new opportunities for investigating the diversity of small Solar System bodies and capturing the real distribution of present material types. We analyze 180 higher-resolution meteor spectra from the All-sky Meteor Orbit System (AMOS) network to identify meteoroids with atypical compositions. In addition to several iron bodies, we identify the first two achondritic meteoroids in our database, both likely meteorite-dropping impactors, and compare them with a reference ordinary chondrite meteoroid observed under similar conditions. Their spectra show strong compositional departures: one case has strong Mg and Si with low Fe, while the other has strong Ca, Al and Ti with low Mg. Derived relative elemental abundances imply an aubrite-like and a eucrite-like composition. The aubrite-like meteoroid exhibits unexpected enhancements in Ca, Mn and Ti in short-lived intensity spikes, which we interpret as rapid release of localized inclusions rather than bulk enrichment. This indicates that transient spectral features can reveal internal heterogeneity in achondritic meteoroids beyond their average composition. Dynamical and physical properties are consistent with these classifications: the eucrite-like meteoroid originated from an inner-main-belt orbit influenced by the $ν_6$ resonance and shows compact ablation with low erosion and an estimated bulk density of 3.16 $\pm$ 0.10 g cm -3; the aubrite-like meteoroid came from a short-period, low-eccentricity orbit similar to some E-type near-Earth asteroids. Both events show atypical light curves, but our results indicate that robust identification of achondritic meteoroids in surveys generally requires emission spectra. This work presents one of the first detailed studies of achondrites from meteor observations and provides reference properties of atypical meteors for future surveys.

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arXiv2022

Hydrogen emission from meteors and meteorites: mapping traces of H$_{2}$O molecules and organic compounds in small Solar system bodies

The hydrogen emission from meteors is assumed to originate mainly from the meteoroid composition, making it a potential tracer of H$_{2}$O molecules and organic compounds. H$α$ line was previously detected in individual fireballs, but its variation in a larger meteor dataset and dependency on the dynamical origin and physical properties have not yet been studied. Here we investigate the relative intensity of H$α$ within 304 meteor spectra observed by the AMOS network. We demonstrate that H$α$ emission is favored in faster meteors ($v_i >>$ 30 km s$^{-1}$) which form the high-temperature spectral component. H$α$ was found to be a characteristic spectral feature of cometary meteoroids with $\sim$ 92% of all meteoroids with detected H$α$ originating from Halley-type and long-period orbits. Our results suggest that hydrogen is being depleted from meteoroids with lower perihelion distances (q $<$ 0.4 au). No asteroidal meteoroids with detected H emission were found. However, using spectral data from simulated ablation of different meteorite types, we show that H emission from asteroidal materials can occur, and apparently correlates with their water and organic matter content. Strongest H emission was detected from carbonaceous chondrites (CM and CV) and achondrites (ureilite and aubrite), while it was lacking in most ordinary chondrites. The detection of H$α$ in asteroidal meteoroids could be used to identify meteoroids of carbonaceous or achondritic composition. Overall, our results suggest that H$α$ emission correlates with the emission of other volatiles (Na and CN) and presents a suitable tracer of water and organic matter in meteoroids.

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arXiv2021

Possibility of transporting material from Ceres to NEO region via 8:3 MMR with Jupiter

In this work we investigate the possibility of transporting material to the NEO region via the 8:3 MMR with Jupiter, potentially even material released from the dwarf planet Ceres. By applying the FLI map method to the 8:3 MMR region in the orbital plane of Ceres, we were able to distinguish between stable and unstable orbits. Subsequently, based on the FLI maps (for mean anomaly $M=60^\circ$ and also $M=30^\circ$), 500 of the most stable and 500 of the most unstable particles were integrated for $15\,Myr$ for each map. Long-term integration in the case of $M=60^\circ$ showed that most of the stable particles evolved, in general, in uneventful ways with only 0.8\% of particles reaching the limit of q $\leq$ 1.3 $AU$. However, in the case of $M=30^\circ$, a stable evolution was not confirmed. Over 40\% of particles reached orbits with q $\leq$ 1.3 $AU$ and numerous particles were ejected to hyperbolic orbits or orbits with a > 100 $AU$. The results for stable particles indicate that short-term FLI maps are more suitable for finding chaotic orbits, than for detecting the stable ones. A rough estimate shows that it is possible for material released from Ceres to get to the region of 8:3 MMR with Jupiter. A long-term integration of unstable particles in both cases showed that transportation of material via 8:3 MMR close to the Earth is possible.

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arXiv2020

On the sodium enhancement in spectra of slow meteors and the origin of Na-rich meteoroids

The detected Na/Mg ratio in a sample of 17 Na-enhanced and Na-rich meteors is investigated based on obtained spectral, orbital and structural data. We utilize the meteor observations of the AMOS network obtained within a survey of medium-sized meteoroids supplemented by higher-resolution spectra observed on the Canary Islands. Ground-based meteor observations are then compared with high-resolution Echelle spectra of simulated ablation of known meteorite samples in a high-enthalpy plasma wind tunnel. It was found that most Na-enhanced and Na-rich spectra can be explained by the effect of low meteor speed related to low ablation temperatures and generally do not reflect real meteoroid composition. Spectra obtained by the laboratory experiment simulating low meteor speeds show corresponding Na-rich profiles irrespectively of the meteorite composition. We estimate that for an H-type ordinary chondrite with speed of $\approx$ 10 km/s, the Na line intensity is increased by a factor of 40 to 95. The dynamical analysis has revealed that all Na-rich meteors originated on Apollo-type orbits and exhibit consistent chondritic material strengths. For more clarity in the classification of Na-enhanced and Na-rich meteoroids, we propose new speed-dependent boundaries between the spectral classes. Real compositional Na enhancement was confirmed in five cometary meteoroids: two Perseids, an $α$-Capricornid, $ν$-Draconid and a sporadic. The two Na-enhanced Perseids were linked with increased material strength suggesting that the detected increase of volatile content has implications for the meteoroid structure.

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arXiv2020

Characterization of the June epsilon Ophiuchids meteoroid stream and the comet 300P/Catalina

Prior to 2019, the June epsilon Ophiuchids (JEO) were known as a minor unconfirmed meteor shower with activity that was considered typically moderate for bright fireballs. An unexpected bout of enhanced activity was observed in June 2019, which even raised the possibility that it was linked to the impact of the small asteroid 2019 MO near Puerto Rico. Early reports also point out the similarity of the shower to the orbit of the comet 300P/Catalina. We aim to analyze the orbits, emission spectra, and material strengths of JEO meteoroids to provide a characterization of this stream, identify its parent object, and evaluate its link to the impacting asteroid 2019 MO. Our analysis is based on a sample of 22 JEO meteor orbits and four emission spectra observed by the AMOS network at the Canary Islands and in Chile. The link to potential parent objects was evaluated using a combination of orbital-similarity D-criteria and backwards integration of the orbit of comet 300P and the JEO stream. We confirm the reports of an unexpected swarm of meteoroids originating in the JEO stream. JEO meteoroids have low material strengths characteristic for fragile cometary bodies, and they exhibit signs of a porous structure. The emission spectra reveal slightly increased iron content compared to all other measured cometary streams, but they are generally consistent with a primitive chondritic composition. Further dynamical analysis suggests that the JEO stream is likely to originate from comet 300P/Catalina and that it was formed within the last 1000 years. Over longer timescales, the meteoroids in the stream move to chaotic orbits due to the turbulent orbital evolution of the comet. Our results also suggest that the impact of the small asteroid 2019 MO on June 22 was not connected to the JEO activity.

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arXiv2019

Spectral and orbital survey of medium-sized meteoroids

We investigate the spectra, material properties, and orbital distribution of millimeter- to decimeter-sized meteoroids. Our study aims to distinguish the characteristics of populations of differently sized meteoroids and reveal the heterogeneity of identified meteoroid streams. We verify the surprisingly large ratio of pure iron meteoroids on asteroidal orbits detected among mm-sized bodies. Emission spectra and multi-station meteor trajectories were collected within the AMOS network observations. The sample is based on 202 meteors of -1 to -14 magnitude, corresponding to meteoroids of mm to dm sizes. Meteoroid composition is studied by relative intensity ratios of Na, Mg, and Fe. Heliocentric orbits, trajectory parameters, and material strengths inferred from empirical $K_B$ and $P_E$ parameters were determined for 146 meteoroids. An overall increase of Na content compared to the population of mm-sized meteoroids was detected, reflecting weaker effects of space weathering processes on larger meteoroids. We report a very low ratio of pure iron meteoroids and the discovery of a new spectral group of Fe-rich meteors. The majority of meteoroids on asteroidal orbits were found to be chondritic. Thermal processes causing Na depletion and physical processes resulting in Na-rich spectra are described and linked to characteristically increased material strengths. Numerous major and minor shower meteors were identified in our sample, revealing various degrees of heterogeneity within Halley-type, ecliptical, and sungrazing meteoroid streams. Our results imply a scattered composition of the fragments of comet 2P/Encke and 109P/Swift-Tuttle. The largest disparities were detected within the $α$-Capricornids and $δ$-Aquarids. We also find a spectral similarity between $κ$-Cygnids and Taurids, which could imply a similar composition of the parent objects of the two streams.

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arXiv2017

Spectra and physical properties of Taurid meteoroids

Taurids are an extensive stream of particles produced by comet 2P/Encke, which can be observed mainly in October and November as a series of meteor showers rich in bright fireballs. Several near-Earth asteroids have also been linked with the meteoroid complex, and recently the orbits of two carbonaceous meteorites were proposed to be related to the stream, raising interesting questions about the origin of the complex and the composition of 2P/Encke. Our aim is to investigate the nature and diversity of Taurid meteoroids by studying their spectral, orbital, and physical properties determined from video meteor observations. Here we analyze 33 Taurid meteor spectra captured during the predicted outburst in November 2015 by stations in Slovakia and Chile, including 14 multi-station observations for which the orbital elements, material strength parameters, dynamic pressures, and mineralogical densities were determined. It was found that while orbits of the 2015 Taurids show similarities with several associated asteroids, the obtained spectral and physical characteristics point towards cometary origin with highly heterogeneous content. Observed spectra exhibited large dispersion of iron content and significant Na intensity in all cases. The determined material strengths are typically cometary in the $K_B$ classification, while $P_E$ criterion is on average close to values characteristic for carbonaceous bodies. The studied meteoroids were found to break up under low dynamic pressures of 0.02 - 0.10 MPa, and were characterized by low mineralogical densities of 1.3 - 2.5 g cm$^{-3}$. The widest spectral classification of Taurid meteors to date is presented.

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arXiv2014

Density, porosity and magnetic susceptibility of the Košice meteorite shower and homogeneity of its parent meteoroid

Bulk and grain density, porosity, and magnetic susceptibility of 67 individuals of Košice H chondrite fall were measured. The mean bulk and grain densities were determined to be 3.43 g/cm$^\text{3}$ with standard deviation (s.d.) of 0.11 g/cm$^\text{3}$ and 3.79 g/cm$^\text{3}$ with s.d. 0.07 g/cm$^\text{3}$, respectively. Porosity is in the range from 4.2 to 16.1%. The logarithm of the apparent magnetic susceptibility (in 10$^\text{-9}$ m$^\text{3}$/kg) shows narrow distribution from 5.17 to 5.49 with mean value at 5.35 with s.d. 0.08. These results indicate that all studied Košice meteorites are of the same composition down to ~g scale without presence of foreign (non-H) clasts and are similar to other H chondrites. Košice is thus a homogeneous meteorite fall derived from a homogeneous meteoroid.

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arXiv2011

Video observation of Geminids 2010 and Quadrantids 2011 by SVMN and CEMeNt

Since 2009 the double station meteor observation by the all-sky video cameras of the Slovak Video Meteor Network (SVMN) brought hundreds of orbits. Thanks to several amateur wide field video stations of the Central European Meteor Network (CEMeNt) and despite not an ideal weather situation we were able to observe several Geminid and Quadrantid multi-station meteors during its 2010 and 2011 maxima, respectively. The presented meteor orbits derived by the UFOOrbit software account a high precision of the orbital elements and are very similar to those of the SonotaCo video meteor database.

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arXiv2011

All-Sky Video Orbits of Lyrids 2009

We report observational results of the Lyrid meteor shower observed by the double station all-sky video system in the night of April 21/22, 2009 at the Astronomical and Geophysical Observatory of the Comenius University in Modra and Arboretum, Tesárske Mlyňany, Slovakia. This observation was the first test of the double stations and orbit determination method within the frame of the new Slovak Video Meteor Network (SVMN). We present the whole set of 17 observed orbits of Lyrids as well as the five most precise orbits in detail form. The comparison with the known datasets, precise photographic IAU MDC and SonotaCo video orbits, demonstrate quite good consistency and similar quality.

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arXiv2011

Orbital evolution of Příbram and Neuschwanstein

The orbital evolution of the two meteorites Příbram and Neuschwanstein on almost identical orbits and also several thousand clones were studied in the framework of the N-body problem for 5000 years into the past. The meteorites moved on very similar orbits during the whole investigated interval. We have also searched for photographic meteors and asteroids moving on similar orbits. There were 5 meteors found in the IAU MDC database and 6 NEAs with currently similar orbits to Příbram and Neuschwanstein. However, only one meteor 161E1 and one asteroid 2002 QG46 had a similar orbital evolution over the last 2000 years.

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arXiv2011

Tidal disruption of NEAs - a case of Příbram

This work studies the dynamical evolution of a possible meteor stream along the orbit of the Příbram meteorite, which originated in the tidal disruption of the putative rubble-pile-like parent body during a close approach to the Earth. We assumed the disruption at the time when the ascending or descending node of the parent orbit was close to the Earth's orbit. In the last 5000 years, the Příbram orbit has crossed the Earth orbit twice. It happened about 4200 years and 3300 years ago. In both cases, we modeled the release of particles from the simplified model of rotating asteroid, and traced their individual orbital evolution to the current date. It takes several hundred years to spread released meteoroids along the entire orbit of the parent body. Even today, the stream would be relatively narrow. Considering a model parent body with physical parameters of the asteroid Itokawa, the complete disintegration of the object produced 3.8$\times10^{11}$ meteoroid particles with diameter $\geq$ 1\,cm. The meteor activity observed from the Earth is revealed and justification of follow-up observation during suggested activity of the shower in the first two weeks of April is discussed. The Earth's tidal forces would disintegrate a fraction of NEA population into smaller objects. We evaluate the upper limit of mass of disintegrated asteroids within the mean NEA lifetime and the contribution of disrupted matter to the size distribution of the NEA.

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arXiv2010

Meteor showers of comet C/1917 F1 Mellish

December Monocerotids and November Orionids are weak but established annual meteor showers active throughout November and December. Analysis of a high quality orbits subset of the SonotaCo video meteor database shows that the distribution of orbital elements, geocentric velocity and also the orbital evolution of the meteors and potential parent body may imply a common origin for these meteors coming from the parent comet C/1917 F1 Mellish. This is also confirmed by the physical properties and activity of these shower meteors. An assumed release of meteoroids at the perihelion of the comet in the past and the sky-plane radiant distribution reveal that the December Monocerotid stream might be younger than the November Orionids. A meteoroid transversal component of ejection velocity at the perihelion must be larger than 100 m/s. A few authors have also associated December Canis Minorids with the comet C/1917 F1 Mellish. However, we did not find any connection.

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arXiv2009

Search for very close approaching NEAs

A simulation of de-biased population of NEAs is presented. The numerical integration of modeled orbits reveals geometrical conditions of close approaching NEAs to the Earth. The population with the absolute magnitude up to H=28 is simulated during one year. The probability of possible discoveries of the objects in the Earth vicinity is discussed.

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arXiv2009

Release of meteoroids from asteroids by Earth's tides

The orbital evolution of particles released from the surface of a rubble-pile body by Earth's tides during flyby within the Roche limit is studied. Test particles initially placed on the surface leave the surface and escape the parent body. Released particles remain in a relative small cloud for about 500 years and spread evenly along the orbit of the parent asteroid during next several hundred years. Their orbital elements exhibit very small dispersion in the mentioned time frame.

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arXiv2009

Relative photometry of transiting exoplanet CoRoT-Exo-2b

Relative CCD photometry of the extrasolar planet COROT-Exo-2b transiting in front of its parent star was carried out at the Astronomical and Geophysical Observatory of Comenius University at Modra (AGO). Physical and orbital parameters were determined and compared with the previous published data.

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